- A new oxo-sterol derivative from the rhizomes of Costus speciosus
-
Chemical investigation of the rhizomes of Costus speciosus led to the isolation of a new compound, 22-ketocholesteryl palmitate (1) along with four known compounds, 24-methylenecycloartanol (2), cycloartanol (3), stigmasterol (4) and linoleic acid (5). The structure of new compound was characterised by extensive 1D-, 2D-NMR and mass spectrometry (GC-MS and HR-ESI-MS) techniques.
- Kumar, Ashish,Chand, Gopi,Agnihotri, Vijai K.
-
-
Read Online
- The major zeaxanthin dipalmitate derivatives from wolfberry
-
Zeaxanthin dipalmitate (3) and two zeaxanthin dipalmitate derivatives, including one new compound (1), were obtained from wolfberry [the fruit of Lycium barbarum L. (Solanaceae)]. Their structures were unambiguously elucidated by spectroscopic analyses. Compound 2 is isolated from the genus Lycium for the first time, and its 1D/2D NMR data are firstly reported. All the compounds belong to carotenoids which are a kind of major bioactive constituents in wolfberry and are also responsible for wolfberry’s red color.
- Long, Jia-Tang,Fan, Hong-Xia,Zhou, Zheng-Qun,Sun, Wan-Yang,Li, Qing-Wen,Wang, Ying,Ma, Min,Gao, Hao,Zhi, Hui
-
-
Read Online
- Efficient conversion of triacylglycerols and fatty acids to biodiesel in a microwave reactor using metal triflate catalysts
-
We report that catalytic quantities of the Lewis acidic metal catalysts scandium triflate and bismuth triflate promote conversion of oleic, linoleic, palmitic and myristic acids and their glyceryl triesters to the corresponding methyl esters (biodiesel) in greater than 90% yield upon microwave heating. Additionally, both catalysts could be recovered and reused in esterification reactions at least six times.
- Socha, Aaron M.,Sello, Jason K.
-
-
Read Online
- Magnetically separable porous carbon nanospheres as solid acid catalysts
-
A novel solid acid material, magnetically separable and SO 3H-functionalized porous carbon nanosphere, was facilely synthesized by a simple activation route. The SiO2 layer protected the magnetic core from dissolving during the process of activation with ZnCl2, and retained the highly magnetic property. The obtained materials were characterized by N2 adsorption-desorption technology and transmission electron microscopy, and the results indicated that this solid acid material possessed an excellent spherical morphology and a superior porosity with high surface area and large pore volume. The results of X-ray diffraction, fourier transform infrared spectra and energy dispersive X-ray spectra demonstrated the preservation of the magnetic core and the successful modification of -SO 3H functional groups. The solid acid activated at a low temperature (400 °C) showed the highest acidity of 1.98 mmol H+ g -1, which was estimated by an indirect titration method. The high surface area, large pore volume and high acidity endued this solid acid material excellent catalytic performance for esterification and transesterification reaction. Besides, the solid acid catalyst possessed remarkable stability and recycling property. The Royal Society of Chemistry 2013.
- Chang, Binbin,Tian, Yanlong,Shi, Weiwei,Liu, Jiyang,Xi, Fengna,Dong, Xiaoping
-
-
Read Online
- A rapid and sensitive profiling of free fatty acids using liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) after chemical derivatization
-
Free fatty acids (FFAs) have diverse roles in cellular energy and signaling and they are critical molecules in various biological states. Due to the poor ionization efficiency of FFAs under electrospray ionization mass spectrometry (ESI-MS) conditions, it is a challenging aspect to construct a robust platform for profiling of various FFAs in biological samples using liquid chromatography ESI-MS. In the present study, we applied trimethylsilyldiazomethane (TMSD) derivatization to improve ionization efficiencies in the profiling of FFAs. Multiple reaction monitoring (MRM) was used for the selective quantification of methylated FFAs. The optimal TMSD methylation was validated for a reliable FFA profiling. Furthermore, the high-throughput analysis of FFAs was successfully performed in short analysis and derivatization times. To verify the utility and effectiveness of the developed method, we compared both methylation and nonmethylation (intact FFA) data in the profiling of FFAs in mice liver and plasma. It is noteworthy that the methylation derivatization provided better results in FFA profiling. Further, we performed statistical data analysis where HBV and mock mice tissues were discriminated when the methylated FFAs data were used. In the lipidomics field, the present method can also be applied for the profiling of FFAs in biological samples for biomarker discovery. The present validated LC/ESI-MS/MS assay method may also be used for FFA profiling modeling studies in other biomedical samples.
- Mok, Hyuck Jun,Lee, Jae Won,Bandu, Raju,Kang, Hong Seok,Kim, Kyun-Hwan,Kim, Kwang Pyo
-
-
Read Online
- Catalytic esterification of fatty acids using solid acid catalysts generated from biochar and activated carbon
-
Reusable, solid acid carbon supported catalysts were generated from biomass by pyrolysis (400-500 °C) to generate a soft to hard carbon backbone (i.e., biochar) for addition of acidic functional groups. Acid catalysts were synthesized by sulfonating the biochar and wood derived activated carbon using concentrated H2SO4 at 100, 150 and 200 °C (12 h) and gaseous SO3 (23 °C). Attenuated Total Reflectance, sulfur, and NH3-TPD analysis of the sulfonated carbons indicated the presence of -SO3H groups on the 100 °C sulfonated biochar and activated carbon (AC), with higher active site densities (SO3H density) for the SO3 sulfonated material. The sulfonated carbons were tested for their ability to esterify free fatty acids with methanol in blends with vegetable oil and animal fat (5-15 wt.% FFA). Esterification of the fatty acids was typically complete (～90-100% conversion) within 30-60 min at 55-60 °C (large methanol excess), but decreased with lower methanol to oil ratios using the biochar catalysts (e.g., 70%, 6 h, 20:1). Solid acid catalysts derived from wood based activated carbon had significantly higher activity compared to the biochar derived catalysts (e.g., 97%, 6 h, 6:1). Of the synthesized biochar catalysts, 400 °C pyrolyzedpine chip biochar, sulfonated at 100 °C, resulted in the highest reaction rate and lowest reduction in conversion (or deactivation) when reused multiple times. Drying the biochar catalysts for 1 h at 125 °C between uses maintained esterification activity, allowing the catalysts to be reused up to 7 cycles. For the SO3 sulfonated AC catalyst, such a regeneration step was not required, as the fractional conversion of palmitic and stearic acid (5% FFA, 10:1, 3 h) remained >90% after 6 cycles.
- Kastner, James R.,Miller, Joby,Geller, Daniel P.,Locklin, Jason,Keith, Lawrence H.,Johnson, Tyson
-
-
Read Online
- 4-Amino-3-pentadecyl-3H-1,2,4-triazole-3-thiones and 3-pentadecyl-1,3,4-oxadiazole-2(3H)-thione for the preparation of dimeric palladium(II) complexes and their applications in Tsuji–Trost and Mizoroki–Heck reactions
-
The synthesis of palladium complexes derived from 4-amino-3-pentadecyl-3H-1,2,4-triazole-3-thiones and 3-pentadecyl-1,3,4-oxadiazole-2(3H)-thiones are reported. They were obtained from palladium acetate and dipotassium tetrachloropalladate(II) and their composition was assigned by elemental analysis (solid state). The resulting metallic entities were also characterized in solution based in mass spectrometry experiments. Their application in organic synthesis as cross-coupling reaction catalysts is described. One example of both conventional Tsuji–Trost and Mizoroki–Heck reactions were efficiently carried out in very high chemical yield.
- Chehrouri, Manel,Othman, Adil A.,Jiménez-Cecilia, Samuel,Moreno-Cabrerizo, Cristina,Sansano, José M.
-
-
Read Online
- Potassium 2-methoxy-4-vinylphenolate: A novel hit exhibiting quorum-sensing inhibition in: Pseudomonas aeruginosa via LasIR/RhlIR circuitry
-
The emergence of multidrug-resistant (MDR) bacterial strains in the last decade is astonishingly alarming. Many of the widely used antibiotics have failed to exhibit clinical efficacy against such strains. Eventually we will exhaust all the resources in our antibiotic armamentarium. As a need of the hour, novel strategies are desperately required not only to curb, but also to reverse, the development of resistance in these pathogens, thereby maintaining their sensitivity towards current antibiotics. Intervention of bacterial virulence, rather than killing them, by inhibiting specific pathways/targets has emerged as a novel approach to tackle the drug resistance problem. The bacterial virulence is regulated via quorum-sensing, a cell-cell communication process precisely controlled by autoinducer molecules such as acyl homoserine lactone (AHL). The present study aimed at identifying promising quorum-sensing inhibitors in Pseudomonas aeruginosa, an opportunistic human pathogen especially associated with nosocomial infections, yielding four potential hits. Out of these, potassium 2-methoxy-4-vinylphenolate was the most potent quorum-sensing inhibitor targeting P. aeruginosa LasIR/RhlIR circuitry. It also inhibited biofilm formation, various virulence factors like LasA protease, LasB elastase and pyocyanin, and motility of bacteria like swarming and twitching.
- Shah, Mayank D.,Kharkar, Prashant S.,Sahu, Niteshkumar U.,Peerzada, Zoya,Desai, Krutika B.
-
-
Read Online
- Biodiesel production by acid catalysis with heteropolyacids supported on activated carbon fibers
-
Different catalysts, based on heteropolyacids supported on activated carbon fibers, have been prepared for palmitic acid esterification reaction. The influence of the catalyst (heteropolyacid) and the support on the catalytic activity have been analyzed. The results prove that an adequate combination of both is required to achieve the most suitable catalysts. Regarding to the heteropolyacid, phosphomolybdic acid seems to be the most suitable appropriate taking into account its lowest leaching. About the support, it must show an optimum microporosity, which must be wide enough to allow the entrance and exit of the reagents and products but not too wide in order to avoid the leaching of the catalyst. In addition, both decreasing of the catalytic activity and its recovery over several cycles have been analyzed.
- Alca?iz-Monge, Juan,Trautwein, Guido,Marco-Lozar, Juan Pablo
-
-
Read Online
- A solvent-free, one-step synthesis of sulfonic acid group-functionalized mesoporous organosilica with ultra-high acid concentrations and excellent catalytic activities
-
We demonstrate herein a novel solvent-free technique for the synthesis of sulfonic acid group-functionalized mesoporous organosilica, which was achieved from the self-assembly of a block copolymer template using mercaptopropyltrimethoxysilane (MPTS) and tetramethoxysilane (TMOS) under melting conditions without using additional solvents and subsequent condensation at high temperature (up to 140 °C). The resultant samples were designated as SMS-xs, where x stands for molar ratio of MPTS/(MPTS + TMOS). SMS-xs have relatively large BET surface areas, highly cross-linked frameworks, and abundant and uniform mesopores with wormhole-like characteristics. Interestingly, MPTS could be used as the solo precursor to prepare mesoporous organosilica (SMS-1.0), which had controllable acidity and an ultra-high concentration of sulfur (5.51 mmol g-1, the highest acid density to date), which was even higher than those of commercial Amberlyst 15 (4.7 mmol g-1), HS-JLU-20-0.8 (4.61 mmol g-1) and sulfonated carbon (CH0.30O0.33S0.16, 4.90 mmol g-1). These structural characteristics give SMS-xs excellent activities and good reusability in biomass conversions and fine chemicals synthesis, which are much better than various solid acids, such as Amberlyst 15, H-form USY zeolite, and sulfonic acid group-functionalized ordered mesoporous silica.
- Wu, Qin,Liu, Fujian,Yi, Xianfeng,Zou, Yongcun,Jiang, Lilong
-
-
Read Online
- Super-Hydrophobic, Stable, and Swelling Nanoporous Solid Strong Acid
-
Super-hydrophobic solid strong acid with superior thermal stability and unique swelling properties has been synthesized by sulfonation of nanoporous polydivinylbenzene (PDVB) with super-acid of trifluoromethanesulfonic acid (TFMSA). The resultant PDVB–HOSO2CF3 has a well developed system of nanopores, superhydrophobic surface character and strong acid sites, and could be used as a highly efficient solid acid for catalyzing production of biodiesel and fine chemicals via transesterification, esterification and acylation. In terms of activity PDVB–HOSO2CF3 is superior to various solid acids such as SBA-15-SO3CF3, Nafion, Amberlyst 15, SBA-15-Ar-SO3H and H form USY. The preparation of PDVB–HOSO2CF3 offers the way to develop new kind of porous solid acid with strong acid strength and regulated wettability.
- Wu, Qin,Peng, Jinjun,Kong, Weiping,Zou, Yongcun
-
-
Read Online
- Can surface energy measurements predict the impact of catalyst hydrophobicity upon fatty acid esterification over sulfonic acid functionalised periodic mesoporous organosilicas?
-
Sulfonic acid functionalised periodic mesoporous organosilicas (PrSO 3H-PMOs) with tunable hydrophobicity were synthesised via a surfactant-templating route, and characterised by porosimetry, TEM, XRD, XPS, inverse gas chromatography (IGC) and ammonia pulse chemisorption. IGC reveals that incorporation of ethyl or benzyl moieties into a mesoporous SBA-15 silica framework significantly increases the non-specific dispersive surface energy of adsorption for alkane adsorption, while decreasing the free energy of adsorption of methanol, reflecting increased surface hydrophobicity. The non-specific dispersive surface energy of adsorption of PMO-SO3H materials is strongly correlated with their activity towards palmitic acid esterification with methanol, demonstrating the power of IGC as an analytical tool for identifying promising solid acid catalysts for the esterification of free fatty acids. A new parameter -ΔGNP-PC, defined as the per carbon difference in Gibbs free energy of adsorption between alkane and polar probe molecules, provides a simple predictor of surface hydrophobicity and corresponding catalyst activity in fatty acid esterification.
- Pirez, Cyril,Lee, Adam F.,Jones, Christopher,Wilson, Karen
-
-
Read Online
- Decoration of chitosan microspheres with Br?nsted heteropolyacids and Lewis ion Ti: Trifunctional catalysts for esterification to biodiesel
-
H3PW12O40 is a commonly used Br?nsted acid catalyst in esterification and transesterification reactions to produce biodiesel, whose homogeneous form and single acid sites lead to difficulties in separation and relatively less activity. Herein, the water-insoluble and multifunctional active sites based on H3PW12O40, chitosan and Ti4+ had been fabricated giving H3PW12O40/Ti/chitosan tri-functional hybrids. Such hybrids exhibited higher activity in esterification reactions due to the existence of Br?nsted acid from H3PW12O40, Lewis acid from Ti4+, and base sites from the -NH2 group of chitosan, and all also due to the generation of pores in chitosan through introduction of the Ti ions. Furthermore, H3PW12O40/Ti/chitosan acted as heterogeneous catalysts and could be separated for reuse at least six times without significant loss of activity and with little leaching of Ti4+ and H3PW12O40 from the support chitosan.
- Tong, Tong,Li, Yiming,Hou, Rui,Wang, Xiaohong,Wang, Shengtian
-
-
Read Online
- Identification of new diterpene esters from green Arabica coffee beans, and their platelet aggregation accelerating activities
-
Eight new ent-kaurane diterpene fatty acid esters, namely caffarolides A–H (1–8), were isolated from green beans of Coffea arabica. Their chemical structures were confirmed by extensive spectroscopic analysis including 1D, 2D NMR (HSQC, HMBC, 1
- Wang, Xia,Meng, QianQian,Peng, XingRong,Hu, GuiLin,Qiu, MingHua
-
-
Read Online
- Clean synthesis of biodiesel over solid acid catalysts of sulfonated mesopolymers
-
FDU-15-SO3H, a solid acid material prepared from the sulfonation of FDU-15 mesoporous polymer, has been demonstrated to serve as an efficient catalyst in the esterification of palmitic acid with methanol as well as in the transesterification of fatty acid-edible oil mixture. FDU-15-SO3H achieved an acid conversion of 99.0% when the esterification was carried out at 343 K with a methanol/palmitic acid molar ratio of 6:1 and 5 wt% catalyst loading. It was capable of giving 99.0% yield of fatty acid methyl esters (FAME) when the transesterification of soybean oil was performed at 413 K and the methanol/oil weight ratio of 1:1. FDU-15-SO3H was further applied to the transesterification/esterification of the oil mixtures with a varying ratio of soybean oil to palmitic acid, which simulated the feedstock with a high content of free fatty acids. The yield of FAME reached 95% for the oil mixtures containing 30 wt% palmitic acid. This indicated the sulfonated mesopolymer was a potential catalyst for clean synthesis of fuel alternative of biodiesel from the waste oil without further purification.
- Fang, Lin,Xing, Rong,Wu, Haihong,Li, Xiaohong,Liu, Yueming,Wu, Peng
-
-
Read Online
- THE STEROIDS AND FATTY ACIDS OF THE BASIDIOMYCETE SCLERODERMA POLYRHIZUM
-
Key Word Index - Scleroderma polyrhizum; Basidiomycete; sterols; fatty acids; ergosta-4,6,8(14),22-tetraene-3-one; 5α,8α-epidioxyergosta-6,22-dien-3β-ol; palmitic acid, oleic acid. The fruit bodies of the Basidiomycete polyrhizum have been shown to contain the steroids ergosta-4,6,8(14),22-tetraen-3-one and 5α,8α-epidioxyergosta-6,22-dien-3β-ol and also palmitic and oleic acids.
- Gonzales, Antonio G.,Barrera, Jaime Bermejo,Marante, Francisco J. Toledo
-
-
Read Online
- Template-free synthesis of porous carbonaceous solid acids with controllable acid sites and their excellent activity for catalyzing the synthesis of biofuels and fine chemicals
-
N rich porous carbon based solid acids (NPC-[CxN][X]) have been successfully synthesized by treatment of N rich porous carbon (NPC) with various quaternary ammoniation reagents such as iodomethane, 1,3-propane sultone, and 1,4-butanesultone, and ion exchange with various strong acids such as HSO3CF3, H2SO4, H3PW12O40, HBF4etc. The NPC support was synthesized by carbonization of KOH-activated polypyrrole without using additional templates. Various characterizations showed that NPC-[CxN][X] possesses abundant nanopores, large Brunauer-Emmett-Teller surface areas, good stability, and strong and controllable acid sites with Br?nsted characteristics. The immobilized acidic groups were homogeneously dispersed into NPC-[CxN][X]. Notably, NPC-[CxN][X] acted as efficient, reusable and generalized solid acids, which showed excellent activity in various acid-catalyzed reactions such as esterification and transesterification in the synthesis of biodiesel, dehydration of fructose into 5-hydroxymethylfurfural, depolymerization of crystalline cellulose into sugars, and condensation of phenol with acetone in the synthesis of bisphenol A, much higher than that of various solid acids such as Amberlyst 15, H-ZSM-5, H-USY, and sulfonic group functionalized ordered mesoporous silicas. The preparation of NPC-[CxN][X] leads to the development of porous carbon based solid acids with controllable structural characteristics and excellent catalytic activity.
- Liu, Fujian,Li, Bojie,Liu, Chen,Kong, Weiping,Yi, Xianfeng,Zheng, Anmin,Qi, Chenze
-
-
Read Online
- The Structure of Wightianone, the Pigment of a Clathrate from Calophyllum wightianum
-
From the heartwood of Calophyllum wightianum T.Anders has been isolated, in small quantities, a clathrate composed of four molecules of a pigment, wightianone, to one of palmitic acid.Other fatty acids are present in small amounts.Wightianone is shown to be identical with zeyloxanthonone and to have the structure (1) .The isomeric structure (2) for the pigment was rejected on the basis of the aromatic solvent-induced shifts and because of biosynthetic considerations, i.e., the occurrence of gem-dialkylation in resorcinol and phloroglucinol but not in quinol nuclei.
- Dean, Francis M.,Khan, Hafizzullah,Minhaj, Najme,Prakash, Satya,Zaman, Asif
-
-
Read Online
- Developing two-dimensional solid superacids with enhanced mass transport, extremely high acid strength and superior catalytic performance
-
Solid acids have been widely used as heterogeneous catalysts in developing green and sustainable chemistry. However, it remains a challenge to improve the mass transport properties and acid strength of solid acids simultaneously. Herein, we report a class of two dimensional (2D) layered hybrid solid acids with outstanding mass transfer and extremely high acid strength by incorporating sulfonated polymers in-between montmorillonite layers. The 2D layered structure and broad distribution of pore sizes allow for highly efficient mass transport of substrate molecules into and out of the solid acids. The acid strength of these solid acids was found to be stronger than that of 100% H2SO4, H3PW12O40 and any other reported solid acids to date, as determined by 1H and 31P solid-state NMR. These 2D solid acids show extraordinary catalytic performance in biomass conversion to fuels, superior to that of H3PW12O40, HCl and H2SO4. Theoretical calculations and control experiments reveal that H-bond based interactions between the polymer and montmorillonite facilitate the unusually high acid strengths found in these samples.
- Liu, Fujian,Yi, Xianfeng,Chen, Wei,Liu, Zhiqiang,Qi, Chen-Ze,Song, Yu-Fei,Zheng, Anmin
-
-
Read Online
- Effect of Fe/Fe2O3 loading on the catalytic activity of sulfonated single-walled carbon nanohorns for the esterification of palmitic acid
-
The effect of dispersion of Fe/Fe2O3 nanoparticles in sulfonated single-walled carbon nanohorns (SO3H/SWCNHs) on their catalytic activity for the esterification of palmitic acid was investigated. A gas-injected arc-in-water (GI-AIW) method was employed to initially synthesize SWCNHs dispersed with iron nanoparticles (Fe-SWCNHs). The Fe-loading amount in the Fe-SWCNHs was varied by changing the number of Fe wires inserted in an anode. The results showed that Fe-loading amount proportionally increased from 6 to 13 wt% with an increase in the number of Fe wires. The surfaces of the Fe-SWCNHs were functionalized with acid functional groups by two sequential steps: impregnation of sulphuric acid and calcination in air. From the characterization results, their acid site concentrations were estimated to be 5.6-8.5 mmol g-1, suggesting that the catalyst was a solid superacid catalyst. XRD analyses indicated that most of the Fe was transformed to α-Fe2O3. The catalytic activity of the SO3H/Fe-SWCNHs for the esterification of palmitic acid was evaluated to investigate the influence of the Fe-loading on their catalytic activity. The results showed that the yield of methyl palmitate was significantly enhanced by an increase in the Fe-loading amount. It was discovered that the catalytic activity and the magnetic susceptibility of SO3H/Fe-SWCNHs can be preserved during repeated use, if the Fe-loading amount is large enough.
- Poonjarernsilp, Chantamanee,Sano, Noriaki,Sawangpanich, Nut,Charinpanitkul, Tawatchai,Tamon, Hajime
-
-
Read Online
- IRISTECTORENES A AND C-G, MONOCYCLIC TRITERPENE ESTERS FROM IRIS TECTORUM
-
Six new triterpene esters, iristectorenes A and C-G, along with one known one have been found in the seeds of Iris tectorum.On the basis of spectroscopic methods and chemical evidence, the esters were established to be 3--2,3-dimethyl-6-(1-methyl-2-oxoethylidene)cyclohexyl>propyl> (Z)-9-tetradecanoate, (Z)-11-hexadecanoate, (Z,Z)-9,12-octadecadienoate, hexadecanoate, (Z)-11-octadecenoate and octadecanoate, respectively.
- Seki, Katsura,Tomihari, Toshiya,Haga, Kazuo,Kaneko, Ryohei
-
-
Read Online
- Anti-inflammatory metabolites from endophytic fungus Fusarium sp
-
Three new ergosterol derivatives, namely, fusaristerols B [(22E,24R)-3-palmitoyl-19(10→6)-abeo-ergosta-5,7,9,22-tetraen-3β-ol] (1), C [(22E,24R)-ergosta-7,22-diene-3β,6β,9α-triol] (3), and D [(22E,24R)-ergosta-7,22-diene-3β,5α,6β,9α-tetraol 6-acetate] (4), along with (22E,24R)-5β,8β-epidioxyergosta-22-en-3β-yl decanoate (2) and (22E,24R)-ergosta-7,22-dien-3β-ol (5), were isolated and characterized from the endophytic fungus Fusarium sp. isolated from Mentha longifolia L. (Labiatae) roots growing in Saudi Arabia. The structures of the isolated metabolites were verified based on UV, IR, NMR (1D and 2D), HRMS, and a comparison with the literature. All the metabolites were assessed for 5-lipoxygenase (5-LOX) inhibitory potential. Compounds 1 and 2 possessed 5-LOX inhibitory potential with an IC50s of 3.61 and 2.45 μM, respectively, compared to that of indomethacin (IC50 1.17 μM). In addition, their structure-activity relationship was discussed.
- Khayat, Maan T.,Ibrahim, Sabrin R.M.,Mohamed, Gamal A.,Abdallah, Hossam M.
-
-
Read Online
- GC-EI-MS analysis of fatty acid composition in brain and serum of twitcher mouse
-
Globoid cell leukodystrophy or Krabbe disease is an inherited autosomal recessive disorder caused by mutations in the galactosylceramidase gene. The objective of the study was to present information about the fatty acid (FA) composition of the brain and serum of twitcher mice, a mouse model of Krabbe disease, compared to wild type, in order to identify biomarker of disease progression. We defined the FA profiles by identifying the main components present in serum and brain using GC-EI-MS analysis. The FA percentage composition was measured and data were analyzed considering the disease and the mouse age as experimental factors. Significant correlations were established, both in brain and in serum, in the fatty acid percentage composition of twitcher compared to wild type mice. The most abundant saturated fatty acid in brain was the palmitic acid (C16:0) with mean values significantly increased in twitcher mouse (p = 0.0142); moreover, three monounsaturated, three polyunsaturated (PUFA) and a plasmalogen were significantly correlated to disease. In the serum highly significant differences were observed between the two groups for three polyunsaturated fatty acids. In fact, the docosahexaenoic acid (C22:6n3c) content was significantly increased (p = 0.0116), while the C20 PUFA (C20:3n6c and C20:5n3c) were significantly decreased in twitcher serum samples. Our study shows a specific FA profile that may help to define a possible pattern that could distinguish between twitcher and wild type; these data are likely to provide insight in the identification of new biomarkers to monitor the disease progression and thereby permit the critical analysis of therapeutic approaches.
- Zanfini, Assunta,Dreassi, Elena,Berardi, Anna,Piomboni, Paola,Costantino-Ceccarini, Elvira,Luddi, Alice
-
-
Read Online
- Esters, retroesters, and a retroamide of palmitic acid: Pool for the first selective inhibitors of N-palmitoylethanolamine-selective acid amidase
-
Cyclohexyl hexadecanoate, hexadecyl propionate, and N-(3-hydroxypropionyl)pentadecanamide, respectively ester, retroester, and retroamide derivatives of N-palmitoylethanolamine, represent the first selective inhibitors of "N-palmitoylethanolamine hydrolase" described so far. These compounds are devoid of affinity for CB1 and CB 2 receptors and characterized by high percentages of inhibition of N-palmitoylethanolamine-selective acid amidase (84.0, 70.5, and 76.7% inhibition at 100 μM, respectively) with much lower inhibitory effect on either fatty acid amide hydrolase or the uptake of anandamide.
- Vandevoorde, Séverine,Tsuboi, Kazuhito,Ueda, Natsuo,Jonsson, Kent-Olov,Fowler, Christopher J.,Lambert, Didier M.
-
-
Read Online
- Fructose induces transketolase flux to promote pancreatic cancer growth
-
Carbohydrate metabolism via glycolysis and the tricarboxylic acid cycle is pivotal for cancer growth, and increased refined carbohydrate consumption adversely affects cancer survival. Traditionally, glucose and fructose have been considered as interchangeable monosaccharide substrates that are similarly metabolized, and little attention has been given to sugars other than glucose. However, fructose intake has increased dramatically in recent decades and cellular uptake of glucose and fructose uses distinct transporters. Here, we report that fructose provides an alternative substrate to induce pancreatic cancer cell proliferation. Importantly, fructose and glucose metabolism are quite different; in comparison with glucose, fructose induces thiaminedependent transketolase flux and is preferentially metabolized via the nonoxidative pentose phosphate pathway to synthesize nucleic acids and increase uric acid production. These findings show that cancer cells can readily metabolize fructose to increase proliferation. They have major significance for cancer patients given dietary refined fructose consumption, and indicate that efforts to reduce refined fructose intake or inhibit fructose-mediated actions may disrupt cancer growth. 2010 AACR.
- Liu, Haibo,Huang, Danshan,McArthur, David L.,Boros, Laszlo G.,Nissen, Nicholas,Heaney, Anthony P.
-
-
Read Online
- A heteropolyacid-based ionic liquid as a thermoregulated and environmentally friendly catalyst in esterification reaction under microwave assistance
-
A new kind of heteropolyacid (HPA) ionic liquid [(CH3) 3NCH2CH2OH]H2PW12O 40 (ChH2PW) has been synthesized using choline chloride and H3PW12O40 (HPW) as precursors. The catalyst exhibited a novel switchable property based on temperature. The separation of the catalyst would be explored by simply decreasing reaction temperature without appreciable loss. Excellent conversions (97%) for esterification have been obtained under microwave-accelerated conditions.
- Duan, Xixin,Sun, Guiru,Sun, Zhong,Li, Jianxin,Wang, Shengtian,Wang, Xiaohong,Li, Shiwu,Jiang, Zijiang
-
-
Read Online
- Antiproliferative and apoptotic effects of compounds from the flower of Mammea siamensis (Miq.) T. Anders. on human cancer cell lines
-
On the search for anti-cancer compounds from Thai traditional herb medicines, a bioassay-guided fractionation and chemical investigation of the methanol extract of Mammea siamensis flower resulted in the isolation and identification of eight compounds (1-8) including a novel geranylated coumarin, namely mammeanoyl (2), and seven known compounds (1 and 3-8). The structure of new compound 2 was elucidated based on the extensive spectroscopic and chemical methods. Among the isolated compounds, three structurally related coumarins 3, 4, and 5 showed significant antiproliferative activities against human leukemia and stomach cancer cell lines. However, these compounds did not affect the cell viabilities of colon cancer, hepatoma, and normal skin fibroblast cell lines. Further analysis demonstrated that the morphological features of apoptosis including DNA fragmentation and chromatin condensation were observed in human leukemia HL-60 cells treated with compounds 3, 4, and 5. In addition, compound 3 led to caspase-3 activation and cleavage of poly (ADP-ribose) polymerase (PARP), and compound 3-induced DNA fragmentation was inhibited by caspase-specific inhibitors. These results suggest that compound 3, 4, and 5 exert antiproliferative actions through apoptotic cell death in leukemia cells and these compounds may have the potential to be developed into new anti-cancer drug candidates.
- Tung, Nguyen Huu,Uto, Takuhiro,Sakamoto, Ayana,Hayashida, Yuka,Hidaka, Yuuki,Morinaga, Osamu,Lhieochaiphant, Sorasak,Shoyama, Yukihiro
-
-
Read Online
- Lipidyl pseudopteranes A-F: Isolation, biomimetic synthesis, and PTP1B inhibitory activity of a new class of pseudopteranoids from the Gorgonian Pseudopterogorgia acerosa
-
Novel lipidyl pseudopteranoids, lipidyl pseudopteranes A-F (1-6), have been isolated from the soft coral Pseudopterogorgia acerosa collected from the Bahamas. Structure elucidation of the six new compounds was based on 1D and 2D NMR data and mass spectrometry, and a biomimetic synthesis of 1 from pseudopterolide (7) was used to help establish its absolute configuration. These structures represent the first report of a pseudopterane diterpene with a fatty acid moiety. Lipidyl pseudopteranes A and D exhibited modest yet selective inhibitory activity against protein tyrosine phosphatase 1B, a promising drug target.
- Kate, Abhijeet S.,Aubry, Isabelle,Tremblay, Michel L.,Kerr, Russell G.
-
-
Read Online
- Water-tolerant heteropolyacid on magnetic nanoparticles as efficient catalysts for esterification of free fatty acid
-
Heteropolyacids (HPAs) supported on magnetic nanoparticles (MNPs) have been prepared by a simple acid-base interaction between functionalized magnetic nanoparticles and HPAs. The surface of the catalyst had been modified by organic groups to protect the catalytic sites from destruction by water. The hybrid SiO2-MNP-HPW consists of a core of magnetic iron oxide MNPs, silica shell, amino-silica and organic groups on the surface, which catalyzed the esterification of palmitic acid with methanol to give 90.4% FFA conversion within 2 h and a high TOF of 4.95 × 102 h-1 under mild reaction conditions. The catalytic performance compared favourably to other solid acid catalysts, demonstrating the advantage of the small size of catalyst particles in reducing mass transfer limitations and providing the substrates with better access to the catalyst sites on the surface of carriers. The catalysts are easily separable from the reaction mixture under a magnetic field and showed high stability and recyclability, with no significant loss of productivity after five cycles of esterification.
- Duan, Xixin,Liu, Yue,Zhao, Qian,Wang, Xiaohong,Li, Shiwu
-
-
Read Online
- Catalytic deoxygenation of oleic acid in continuous gas flow for the production of diesel-like hydrocarbons
-
Continuous gas phase deoxygenation of oleic acid in the presence of hydrogen employing a granular 2 wt% Pd/C catalyst was investigated under solvent free conditions. Conversion of oleic acid and selectivity to the desired diesel-like C17 hydrocarbons heptadecane and heptadecenes was studied at different reaction conditions such as temperature, gas flow and catalyst amount. The best hydrocarbon yield was achieved with low reaction temperatures, high catalyst amounts and high hydrogen flows. To further decrease the reaction temperature but yet maintain a pure gas phase reaction, reactions were conducted in vacuum. Furthermore, water was added in varying amounts to support desorption and to determine if catalyst deactivation could be overcome. The deoxygenation catalyst was characterized by nitrogen adsorption isotherms (BET; Brunauer-Emmet-Teller method), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM).
- Arend, Matthias,Nonnen, Thomas,Hoelderich, Wolfgang F.,Fischer, Jürgen,Groos, Jeremie
-
-
Read Online
- A new triterpenoid ester from lobelia sessilifolia
-
One novel triterpenoid ester, oleanol 28-aldehyde 3-Oβ-palmitate (1), was isolated from the aerial part of Lobelia sessilifolia Lamb. along with seven known compounds, namely two triterpenoid esters (2, 3), one sterol (4), two coumarins (5, 6), and two triterpenes (7, 8). The structure of 1 was established on the basis of spectroscopic and chemical data.
- Sun, Jiaming,Wang, Xiuli,Zhang, Hui,Yang, Junshan
-
-
Read Online
- Regiospecific synthesis of new fatty N-acyl trihalomethylated pyrazoline derivatives from fatty acid methyl esters (FAMEs)
-
A series of new fatty N-acyl trihalomethylated pyrazoline derivatives from fatty acid methyl esters was synthesized by the cyclocondensation of respective fatty hydrazides with 4-alkoxy-1,1,1-trialomethyl-3-alquen-2-ones. Efficient and regiospecific cyclizations catalyzed by BF3·MeOH gave the desired products in good to excellent yields and at high purity.
- Beck, Paulo,Dos Santos, Juliane M.,Kuhn, Bruna L.,Moreira, Dayse N.,Flores, Alex F. C.,Martins, Marcos A. P.,D'Oca, Marcelo G. M.,Piovesan, Luciana A.
-
-
Read Online
- Lipoteichoic acid anchor triggers Mincle to drive protective immunity against invasive group A Streptococcus infection
-
Group A Streptococcus (GAS) is a Gram-positive bacterial pathogen that causes a range of diseases, including fatal invasive infections. However, the mechanisms by which the innate immune system recognizes GAS are not well understood. We herein report that the C-type lectin receptor macrophage inducible C-type lectin (Mincle) recognizes GAS and initiates antibacterial immunity. Gene expression analysis of myeloid cells upon GAS stimulation revealed the contribution of the caspase recruitment domain-containing protein 9 (CARD9) pathway to the antibacterial responses. Among receptors signaling through CARD9, Mincle induced the production of inflammatory cytokines, inducible nitric oxide synthase, and reactive oxygen species upon recognition of the anchor of lipoteichoic acid, monoglucosyldiacylglycerol (MGDG), produced by GAS. Upon GAS infection, Mincle-deficient mice exhibited impaired production of proinflammatory cytokines, severe bacteremia, and rapid lethality. GAS also possesses another Mincle ligand, diglucosyldiacylglycerol; however, this glycolipid interfered with MGDG-induced activation. These results indicate that Mincle plays a central role in protective immunity against acute GAS infection.
- Imai, Takashi,Matsumura, Takayuki,Mayer-Lambertz, Sabine,Wells, Christine A.,Ishikawa, Eri,Butcher, Suzanne K.,Barnett, Timothy C.,Walker, Mark J.,Imamura, Akihiro,Ishida, Hideharu,Ikebe, Tadayoshi,Miyamoto, Tomofumi,Ato, Manabu,Ohga, Shouichi,Lepenies, Bernd,Van Sorge, Nina M.,Yamasaki, Sho
-
p. E10662 - E10671
(2018)
-
Read Online
- Sterols and Fatty Acids of the Harmful Dinoflagellate Cochlodinium polykrikoides
-
Sterol and fatty acid compositions were determined for Cochlodinium polykrikoides, a toxic, bloom-forming dinoflagellate of global significance. The major sterols were dinosterol (40% of total sterols), dihydrodinosterol (32%), and the rare 4α-methyl Δ8(14) sterol, amphisterol (23%). A minor sterol, 4α-methylergost-24(28)-enol was also detected (5.0%). The fatty acids had a high proportion of PUFAs (47%), consisting mainly of EPA (20%) and the relatively uncommon octadecapentaenoic acid (18: 5, 22%). While unlikely to be responsible for toxicity to fish, these lipids may contribute to the deleterious effects of this alga to invertebrates.
- Giner, José-Luis,Ceballos, Harriette,Tang, Ying-Zhong,Gobler, Christopher J.
-
-
Read Online
- Identification and α -Glucosidase Inhibitory Activity of Meroterpenoids from Hericium erinaceus
-
Hericium erinaceus is a very popular edible and medicinal mushroom used for the treatment of enervation and gastrointestinal diseases in Eastern Asia. Chemical investigation on the fruiting body of Hericium erinaceus led to the isolation of 4 new (1 - 4) and 10 known meroterpenoids (5 - 14). The structures of new compounds were determined via analysis of NMR and MS data in combination with chemical derivatization. The inhibitory activities of 1 - 14 against α -glucosidase were evaluated using p -nitrophenyl- α -D-glucopyranoside, sucrose, or maltose as substrate. Compounds 6, 9, 11 - 13 were demonstrated to show the α -glucosidase inhibitory activities. This work confirms the potential of H. erinaceus in the treatment of diabetes.
- Bao, Li,Chen, Baosong,Han, Junjie,Liu, Hongwei,Ma, Ke,Wang, Wenzhao
-
-
Read Online
- Production of biodiesel through esterification of palmitic acid using 12-tungestoposphoric acid supported on nanocavity of aluminium incorporated mesoporous SBA-15
-
The main aim of this research is to develop efficient and environmentally benign heterogeneous catalysts for biodiesel production. For this purpose, H3PW12O40 (PW12) supported on Al-functionalized SBA-15 mesoporous molecular sieve featuring a well-defined three-dimensional (3D) mesoporosity were studied, and the prepared catalyst (PW12/Al-SBA-15) was tested for the esterification process of palmitic acid to produce methyl palmitate as a kind of biodiesel. The effects of the methanol/oil ratio, catalyst amounts, reaction time, and reaction temperature on the conversion are also reported in this paper. More importantly, by using a 35 wt % of PW12/Al-SBA-15 with methanol/oil molar ratio of 20: 1 at reflux of methanol, the oil conversion of 98% after 8 h of reaction, could be achieved over the solid catalyst for at least 6 cycles under mild conditions.
- Fazaeli, Razieh,Aliyan, Hamid
-
-
Read Online
- Non-cannabinoid constituents from a high potency Cannabis sativa variety
-
Six new non-cannabinoid constituents were isolated from a high potency Cannabis sativa L. variety, namely 5-acetoxy-6-geranyl-3-n-pentyl-1,4-benzoquinone (1), 4,5-dihydroxy-2,3,6-trimethoxy-9,10-dihydrophenanthrene (2), 4-hydroxy-2,3,6,7-tetramethoxy-9,10-dihydrophenanthrene (3), 4,7-dimethoxy-1,2,5-trihydroxyphenanthrene (4), cannflavin C (5) and β-sitosteryl-3-O-β-d-glucopyranoside-2′-O-palmitate (6). In addition, five known compounds, α-cannabispiranol (7), chrysoeriol (8), 6-prenylapigenin (9), cannflavin A (10) and β-acetyl cannabispiranol (11) were identified, with 8 and 9 being reported for the first time from cannabis. Some isolates displayed weak to strong antimicrobial, antileishmanial, antimalarial and anti-oxidant activities. Compounds 2-4 were inactive as analgesics.
- Radwan, Mohamed M.,ElSohly, Mahmoud A.,Slade, Desmond,Ahmed, Safwat A.,Wilson, Lisa,El-Alfy, Abir T.,Khan, Ikhlas A.,Ross, Samir A.
-
-
Read Online
- Dual-catalytic decarbonylation of fatty acid methyl esters to form olefins
-
The homogeneous dehydrative decarbonylation of fatty acid methyl esters (FAMEs) to form olefins is reported. In order to facilitate cleavage of the unactivated acyl C-O bond of the alkyl ester, a one pot dual-catalytic directing group strategy was developed through optimization of the individual transesterification and decarbonylation reaction steps.
- Fieser, Megan E.,Schimler, Sydonie D.,Mitchell, Lauren A.,Wilborn, Emily G.,John, Alex,Hogan, Levi T.,Benson, Brooke,LaPointe, Anne M.,Tolman, William B.
-
-
Read Online
- Sustainable production of biodiesel and transformation of glycerol to glycerol laurate esters over inner diameter-controlled sulfonic acid functionalized ethyl-bridged-organosilica nanotubes
-
Solid acid-catalyzed biodiesel production from inedible oils offers a promising mean to reduce the cost of feedstocks and avoid the competition with edible oil market. Here we demonstrate a series of inner diameter-controlled sulfonic acid functionalized ethyl-bridged-organosilica nanotubes (Ar/PrSO3H–Si(Et)Si) by a toluene swollen mixed Pluronic surfactant micelle-templating co-condensation route for transesterification of tripalmitin or plant oils with methanol to produce fatty acid methyl esters and esterification of glycerol with lauric acid to produce mono- and di-glycerol esters. By combination of superstrong Br?nsted acidity, unique hollow tubular nanostructure, excellent porosity properties and hydrophobic surface, the Ar/PrSO3H–Si(Et)Si nanotubes display higher catalytic activity as compared with acidic resin and zeolite. Additionally, the inner diameters and lengths of Ar/PrSO3H–Si(Et)Si nanotubes influence the activity obviously. The Ar/PrSO3H–Si(Et)Si nanotubes also show excellent catalytic reusability, attributing to covalent bonding of Ar/PrSO3H groups within silica/carbon framework and surface hydrophobicity of the catalysts.
- Guo, Yihang,Liu, Jingyu,Song, Daiyu,Wu, Qingyin,Zhang, Chaoyue,Zhang, Qingqing
-
-
Read Online
- Cucumol B, a new triterpene benzoate from Cucumis melo seeds with cytotoxic effect toward ovarian and human breast adenocarcinoma
-
Phytochemical investigation of the methanolic extract of Cucumis melo L. (Cucurbitaceae) seeds furnished a new triterpene benzoate derivative: cucumol B (1) and four known flavonoids: quercetin-3-O-β-D-glucopyranosyl-(1→6)-α-L-rhamnopyranoside (2), quercetin-3-O-β-D-glucopyranoside (3), quercetin (4), and luteolin (5). Their structures were identified by UV, IR, 1D (13C and 1H), 2D (HSQC, 1H-1H COSY, HMBC, and NOESY) NMR, and HRESIMS spectral as well as comparing with literature data. Compound 1 has been assessed for the in vitro cytotoxic effect against SKOV-3, MCF-7, and HCT-116 cell lines. It had selective and potent effect toward SKOV-3 and MCF-7 cell lines with IC50s 2.05 and 0.41 μM, respectively, in comparison to doxorubicin (IC50s 0.32 and 0.05 μM). However, it showed moderate activity toward HCT-116 cell line with IC50 8.27 μM.
- Ibrahim, Sabrin Ragab Mohamed,Khedr, Amgad Ibrahim Mansour,Mohamed, Gamal Abdallah,Zayed, Mohamed Fathalla,El-Kholy, Amal Abd-Elmoneim Soliman,Al Haidari, Rwaida Adel
-
-
Read Online
- Organosulfonic acid-functionalized mesoporous silicas for the esterification of fatty acid
-
The transesterification of vegetable oils with short-chain alcohols has shown potential application as an intermediate for value-added products, e.g., fatty alcohols and biodiesel. Organosulfonic acid-functionalized mesoporous silicas were synthesized in a one-step approach of co-condensing inorganic-organic reagents in the presence of different surfactant templates with in situ oxidation of the thiol groups to the sulfonic acid groups. The resulting materials were tested for their catalytic performance in the esterification of fatty acid with methanol to produce methyl esters. The performance of the functionalized mesoporous materials demonstrated a strong dependence on the median pore diameter of the catalyst as well as the acidic strength of the organosulfonic acid group. A comparison of the activity of the organosulfonic acid-functionalized silicas in the esterification to that of standard acidic resins showed the potential of rational catalysis design using organic-inorganic mesoporous materials.
- Mbaraka, Isa K.,Radu, Daniela R.,Lin, Victor S.-Y.,Shanks, Brent H.
-
-
Read Online
- PALMILYCORINE AND LYCORISIDE: ACYLOXY AND ACYLGLUCOSYLOXY ALKALOIDS FROM CRINUM ASIATICUM
-
Two new types of alkaloidal conjugates, a C16-acyloxy derivative, named palmilycorine, and an acylglucosyloxy derivative, named lycoriside, were isolated from the fruits of Crinum asiaticum.The presence of these compounds was also detected in the fleshy scale leaves and in roots of these species.The structures of the two compounds were established as 1-O-palmitoyllicorine (1) and lycorine-1-O-(6'-O-palmitoyl-β-D-glucopyranoside) (2), respectively, on the basis of chemical transformation and comprehensive spectral evidence.The biological effects of the alkaloids were evaluated. Key Word Index - Crinum asiaticum; Amaryllidaceae; fruits; alkaloids; alkaloidal conjugates; palmilycorine, 1-O-palmitoyllicorine; lycoriside, lycorine-1-O-(6'-O-palmitoyl-β-D-glucopyranoside); lycorine-1-O-β-D-glucoside; promoters of cell viability, cell growth and root growth.
- Ghosal, Shinbath,Shanthy, Amirthalingam,Kumar, Anand,Kumar, Yatendra
-
-
Read Online
- Glycerogalactolipids from the fruit of Lycium barbarum
-
Four glycerogalactolipids (1-4), together with 11 other previously known homologues were isolated from the fruit of Lycium barbarum. Their structures were elucidated by chemical analyses including regio-selective enzymatic, alkaline and acidic hydrolyses and spectroscopic methods involving GCMS, HRESIMS and 1D and 2D NMR, respectively.
- Gao, Zengping,Ali, Zulfiqar,Khan, Ikhlas A.
-
-
Read Online
- Chemoenzymatic Generation of Phospholipid Membranes Mediated by Type i Fatty Acid Synthase
-
The de novo formation of lipid membranes from minimal reactive precursors is a major goal in synthetic cell research. In nature, the synthesis of membrane phospholipids is orchestrated by numerous enzymes, including fatty acid synthases and membrane-bound acyltransferases. However, these enzymatic pathways are difficult to fully reproduce in vitro. As such, the reconstitution of phospholipid membrane synthesis from simple metabolic building blocks remains a challenge. Here, we describe a chemoenzymatic strategy for lipid membrane generation that utilizes a soluble bacterial fatty acid synthase (cgFAS I) to synthesize palmitoyl-CoA in situ from acetyl-CoA and malonyl-CoA. The fatty acid derivative spontaneously reacts with a cysteine-modified lysophospholipid by native chemical ligation (NCL), affording a noncanonical amidophospholipid that self-Assembles into micron-sized membrane-bound vesicles. To our knowledge, this is the first example of reconstituting phospholipid membrane formation directly from acetyl-CoA and malonyl-CoA precursors. Our results demonstrate that combining the specificity and efficiency of a type I fatty acid synthase with a highly selective bioconjugation reaction provides a biomimetic route for the de novo formation of membrane-bound vesicles.
- Khanal, Satyam,Brea, Roberto J.,Burkart, Michael D.,Devaraj, Neal K.
-
-
Read Online
- Design and synthesis of micro-meso-macroporous polymers with versatile active sites and excellent activities in the production of biofuels and fine chemicals
-
Micro-meso-macroporous polymers (MOPs) grafted with versatile functional groups, such as sulfonate, amine, triazole, pyridine, strong acidic ionic liquids and triphenylphosphine, were synthesized by in situ cross-linking of different functional molecules with 1,4-bis(chloromethyl)benzene in the presence of Lewis acid catalysts without using additional templates. The resultant hyper-cross-linked nanoporous polymers show unique characteristics such as large BET surface areas (up to 1523 m2 g-1), abundant micro-meso-macropores (4.5-131 nm), and tunable and versatile active sites (acid, base and palladium). These functional polymers exhibit excellent activities and good reusability in biomass conversions, cross-coupling reactions and condensation. The catalytic activities are much better than those of various conventional catalysts such as H3PW12O40, SBA-15-SO3H, Amberlyst 15, and mesoporous H-ZSM-5 Pd/C and even as comparable as those of homogeneous H2SO4 and HCl in the depolymerization of crystalline cellulose into fine chemicals and towards transesterification to biodiesel. This work highlights a low cost route to the synthesis of solid catalysts based on functional nanoporous polymers for catalyzing the production of clean biofuels and fine chemicals.
- Liu, Fujian,Liu, Chen,Kong, Weiping,Qi, Chenze,Zheng, Anmin,Dai, Sheng
-
-
Read Online
- High-temperature synthesis of strong acidic ionic liquids functionalized, ordered and stable mesoporous polymers with excellent catalytic activities
-
Strong acidic ionic liquids functionalized, ordered and stable mesoporous phenol-formaldehyde resins (OMR-ILs) monoliths have been successfully synthesized from the treatment of ordered mesoporous resins (OMR-[HMTA]) using 1,3-propanesultone, followed by ion exchanged using various strong acids. The OMR-[HMTA] samples could be synthesized by the assembly of block copolymer template of F127 with preformed resol, which could be obtained from heating a mixture of phenol and formaldehyde at 70 °C; during curing processes, certain contents of the hexamethyltetramine (HMTA) cross linker were also introduced, after hydrothermal treatment at 200 °C for 20 h, calcination at 360 °C under nitrogen, OMR-[HMTA] samples with opened mesopores were obtained. Characterizations suggest that OMR-ILs have ordered and stable mesospores, high BET surface areas, and strong acid strength. Interestingly, OMR-ILs show much higher catalytic activities and recyclability in the esterification of acetic acid with cyclohexanol, hydration of propylene oxide, Peckmann reaction of resorcinol with ethyl acetoacetate and transesterification of tripalmitin with methanol than those of Amberlyst 15, sulfonic group functional ordered mesoporous silicas and acidic zeolites, which were even comparable with that of H2SO4. The unique features of OMR-ILs such as superior thermal stability, excellent catalytic activities and recyclability, will be potentially important for their applications in industry.
- Liu, Fujian,Zuo, Shufeng,Kong, Weiping,Qi, Chenze
-
-
Read Online
- Four new phorbol diesters from Croton tiglium and their cytotoxic activities
-
Phytochemical investigation of the seeds of Croton tiglium resulted in the isolation and structure elucidation of four new 4-deoxy-4β-phorbol diesters (1-4) named as 12-O-tiglylphorbol-4-deoxy-4β-phorbol-13-acetate (1), 12-O-tiglylphorbol-4-deoxy-4β-phorbol-13-hexadecanoate (2), 13-O-acetylphorbol-4-deoxy-4β-phorbol-20-oleate (3) and 13-O-acetylphorbol-4-deoxy-4β-phorbol-20-linoleate (4), respectively. The structures of the new compounds were established by 1D, 2D-NMR and HR-ESI-MS spectroscopic data and chemical degradation experiments. The cytotoxic activities of compounds 1-4 were evaluated against hepatic tumor cell lines (SNU387 and SNU398). Among these compounds, compound 4 exhibited the most potent activity against the SNU387 with IC50 value of 0.71 μM.
- Zhang, Xiao-Long,Khan, Ashfaq-Ahmad,Wang, Lun,Yu, Kai,Li, Fu,Wang, Ming-Kui
-
-
Read Online
- Determining the role of oxygen vacancies in palmitone selectivity and coke formation over acid metal oxide catalysts for the ketonization of methyl palmitate
-
In the present study, TiO2, CeO2, MnO2, and ZrO2 catalysts were used to investigate the catalytic performance in methyl palmitate ketonization. The reaction was accelerated by weak Lewis acid, while the oxygen v
- Guntida, Adisak,Jongsomjit, Bunjerd,Praserthdam, Piyasan,Praserthdam, Supareak,Rattanachartnarong, Thanwarat,Sooknoi, Tawan,Weerachawanasak, Patcharaporn
-
-
- Chemically Modified Lipase from Thermomyces lanuginosus with Enhanced Esterification and Transesterification Activities
-
Lipase from Thermomyces lanuginosus is one of the most explored enzymes for the esterification of several added-value industrial compounds, such as biodiesel, fragrances, and flavors. Its selectivity in these reactions is mostly related with its activity towards small alcohols. In this work, the impact of the chemical modification, with 4 dodecyl chains at its surface, was evaluated regarding its transesterification and esterification activities, comparing with the native form. Linear size-differentiated alcohols (from 1 to 20 carbons in the aliphatic chain) were used to explore for the first time the effect of the chain length in both transesterification and esterification reactions, using p-nitrophenyl palmitate and oleic acid as model compounds, respectively. The chemically modified lipase showed an outstanding improvement of its catalytic performance than the native enzyme, being this increase directly proportional to the size of the alcohols chain used as substrates. The enormous potential and remarkable versatility of this novel super catalyst was here demonstrated, where diverse types of esters, differing in their potential applications (biodiesel, cosmetics, fine chemistry), were efficiently synthesized. The produced esters were fully characterized by 1H NMR, GC-MS, and FTIR.
- Noro, Jennifer,Cavaco-Paulo, Artur,Silva, Carla
-
p. 4524 - 4531
(2021/09/02)
-
- Oxidative esterification of alcohols by a single-side organically decorated Anderson-type chrome-based catalyst
-
The direct esterification of alcohols with non-noble metal-based catalytic systems faces great challenges. Here, we report a new chrome-based catalyst stabilized by a single pentaerythritol decorated Anderson-type polyoxometalate, [N(C4H9)4]3[CrMo6O18(OH)3C{(OCH2)3CH2OH}], which can realize the efficient transformation from alcohols to esters by H2O2oxidation in good yields and high selectivity without extra organic ligands. A variety of alcohols with different functionalities including some natural products and pharmaceutical intermediates are tolerated in this system. The chrome-based catalyst can be recycled several times and still keep the original configuration and catalytic activity. We also propose a reasonable catalytic mechanism and prove the potential for industrial applications.
- Wang, Jingjing,Jiang, Feng,Tao, Chaofu,Yu, Han,Ruhlmann, Laurent,Wei, Yongge
-
supporting information
p. 2652 - 2657
(2021/04/21)
-
- Synthesis and characterization of biodegradable palm palmitic acid based bioplastic
-
This study involves the quantitative analysis of high free fatty acid crude palm oil, the separation of palmitic acid and synthesis of palm palmitic acid-based bioplastic. Synthesis of dimethyl 2-tetradecylmalonate (DMTDM) using methyl palmitate (MP) with sodium hydride (NaH) in the presence of reactive solvent of dimethyl carbonate (DMC) was carried out. The reaction conditions comprise at a mole ratio of MP: DMC: NaH: Dimethylformamide (DMF) (0.1:2:0.25:1) at 60 °C for 14 h with 88.3 ± 1.4% yield. FTIR spectra of DMTDM showed the ester carbonyl group at 1740 cm-1. The polymerization of DMTDM with 1,6-hexandiol or 1,12-dodecandiol was carried out using titanium (IV) isopropoxide Ti(OiPr)4 as the catalyst and reaction time of 24 h. The results showed that the poly(dodecyl 2-tetradecylmalonte) (PDTDM) exhibited good thermal properties compared to poly(hexyl 2-tetradecylmalonte) (PHTDM). The increase of the chain length of diol in PDTDM improved the thermal properties of polyester with glass transition, Tg of 13 °C and melting point of 51 °C with a molecular weight of 12508 Da and polydispersity index (PDI) of 1.4. In general, the synthetic polyesters can be used as internalplasticizer in bio-based industry.
- Japir, Abd Al-Wali,Salih, Nadia,Salimon, Jumat
-
p. 585 - 599
(2021/07/26)
-
- FLOW CHEMISTRY SYNTHESIS OF ISOCYANATES
-
The disclosure provides, inter alia, safe and environmentally-friendly methods, such as flow chemistry, to synthesize isocyanates, such as methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and tetramethylxylene diisocyanate.
- -
-
Paragraph 0175; 0186-0187; 0270-0272
(2021/06/22)
-
- Phytochemical studies of melilotus officinalis
-
GC-MS analysis of the n-hexane extract of Melilotus officinalis seeds revealed twelve compounds with a combined area percentage of 98.33% predominantly, (9Z,12Z)-octadecadienoic acid (20.22%, 366 ppm), 14-methylpentadecanoic acid (19.52%, 353 ppm) and (9E)-octadecenoic acid (15.94%, 289 ppm). Two compounds, namely, cis-coumaric acid-2-O-β-D-glucopyranoside (cis-melilotoside, 1) and 1,2-benzopyrone (coumarin, 2), were isolated from the MeOH extract of the seeds of M. officinalis. The structures of isolated compounds were determined by spectroscopic techniques such as NMR, UV-Vis, and FTIR. The MeOH extract of M. Officinalis was also tested for its antioxidant activity using DPPH assay. The extract showed 29.87% DPPH inhibition at concentration of 100 μg/mL.
- Mammo, Wendimagegn,Sisay, Melaku Assefa,Yaya, Estifanos Ele
-
p. 141 - 150
(2021/06/03)
-
- Protic ionic liquids from di- or triamines: even cheaper Br?nsted acidic catalysts
-
Dicationic and tricationic ionic liquids, synthesised by proton transfer from sulfuric acid and corresponding di- and triamines, were characterised and used as Br?nsted acidic catalysts in biodiesel production. It has been demonstrated that the new ionic liquids are less expensive than those based on monoamines (even on triethylamine) and are highly acidic. Their performance in a model catalytic esterification reaction surpassed that of sulfuric acid and other literature reports, due to the capability of the ionic liquids to absorb water while phase-separating the ester, thereby shifting the reaction equilibrium towards products. The overall catalytic performance was an interplay between acidity (quantified by Gutmann AN) and physical properties: density and viscosity, which enabled easy phase separation, thereby separating water from the ester. The substrate scope and recycling studies have demonstrated that the new ionic liquids are robust and recyclable catalysts.
- Barteczko, Natalia,Brz?czek-Szafran, Alina,Byrne, Emily,Chrobok, Anna,Kolanowska, Anna,Swad?ba Kwa?ny, Ma?gorzata,Szelwicka, Anna,Wi?c?awik, Justyna
-
p. 4421 - 4429
(2021/06/28)
-
- Novel synthesized microporous ionic polymer applications in transesterification of Jatropha curcas seed oil with short Chain alcohol
-
New suites of sulfonic acid-functionalized microporous ionic polymers (PIPs) catalysts were synthesized with polymer, alkyl bromides, and 1, 3-propane sultone via a two-step procedure. The synthesized microporous PIP catalysts were characterized using FT-IR, SEM-Mapping, XPS, N2 adsorption–desorption isotherms, solid NMR spectroscopy, and element analysis. Esterification of several fatty acids with ethanol, which was used as a model reaction in the stabilization of Jatropha curcas seed oil, was checked over functionalized PIP. We tested the catalytic performance of PIP-C8 on the synthesis of fatty acid esters via the transesterification of J. curcas seed oil with a mixture of short-chain alcohols such as ethanol, ethanol–to–diethyl carbonate (1;1 molar ratio), and ethanol–to–dimethyl carbonate (1:1 molar ratio) with 170 mg of PIP-C8 at reflux temperature with agitation. The PIP-C8 catalyst was particularly effective, having achieved yields of 85%, 94%, and 70% for J. curcas seed oil with ethanol, J. curcas seed oil with ethanol–to–DEC, and J. curcas seed oil with ethanol–to–DMC, respectively, under the optimized reaction conditions. The catalyst could be recycled more than five times without significant deactivation. Kinetic studies performed at different temperatures revealed that the conversion of oleic acid to an ethyl ester follows a first-order reaction. The best catalysts with microporous structure (average pore diameter: 1.7–1.9 nm, pore volume: 0.23–0.33 cm3 g–1) and –SO3H density (0.70–0.84 mmol/gcat) were obtained by 1, 3-propane sultone of the chemically activated. The results indicate that the site activity of functionalized microporous ionic polymer materials shows promising approach for the development of environmentally friendly technology.
- Chang, Tao,Hao, Yongjing,Jinxi, Jinxi,Kai, Kai,Panchal, Balaji,Qin, Shenjun,Sun, Yuzhuang,Zhao, Cunling,Zhao, Qiaojing,Zhu, Zheng
-
-
- Encapsulation of heteropolyacids within hollow microporous polymer nanospheres for sustainable esterification reaction
-
Herein, the Keggin structural phosphotungstic acid (HPW) has been successfully encapsulated within hollow microporous polymer nanospheres (H-MPNs) by a “ship-in-bottle” approach. The H-MPNs are formed by self-assembly induced by hyper-crosslinking of polylactide-b-polystyrene (PLA-b-PS). The obtained catalysts (HPW@H-MPNs) exhibit more sustainable availability than the previously reported HPW-supported catalysts in esterification reaction. This excellent sustainability can be attributed to the stable microporous channels in H-MPNs which are smaller than the molecular size of HPW, thereby effectively preventing the HPW from leaking out. Moreover, such catalysts also perform well in terms of catalytic activity and universality because of the combination of a hollow structure in the interior and permeable pore channels in the shells. This type of polymer carrier and general encapsulation method may provide a new strategy for developing more sustainable catalysts for various chemical reactions.
- He, Zhiwei,Huang, Kun,Song, Chunmei,Wang, Huaqing,Yu, Haitao,Zhang, Li
-
-
- Ruthenium-catalyzed hydrogenation of CO2as a route to methyl esters for use as biofuels or fine chemicals
-
A novel robust diphosphine-ruthenium(ii) complex has been developed that can efficiently catalyze both the hydrogenation of CO2 to methanol and its in situ condensation with carboxylic acids to form methyl esters; a TON of up to 3260 is achievable for the CO2 to methanol step. Both aromatic and aliphatic carboxylic acids can be transformed to their corresponding methyl esters with high conversion and selectivity (17 aliphatic and 18 aromatic examples). On the basis of a series of experiments, a mechanism has been proposed to account for the various steps involved in the catalytic pathway. More importantly, this approach provides a promising route for using CO2 as a C1 source for the production of biofuels, fine chemicals and methanol.
- Li, Yong,Liu, Qingbin,Ma, Yanping,Solan, Gregory A.,Sun, Wen-Hua,Wang, Zheng,Zhang, Qiuyue,Zhao, Ziwei,Zhong, Yanxia
-
p. 6766 - 6774
(2020/08/25)
-
- Highly ordered mesoporous functionalized pyridinium protic ionic liquids framework as efficient system in esterification reactions for biofuels production
-
Polysiloxane acidic ionic liquids containing pyridinium trifluoroacetate salts (PMO-Py-IL) were synthesized from pyridine containing organosilane precursors. Characterization by SEM, XRD, TGA, and nitrogen porosimetry confirmed that both pyridinium cation and trifluoroacetate anion were successfully incorporated within the organosilica network. The resulting organic-inorganic hybrid nanomaterial (PMO-Py-IL) was studied as nanocatalyst in free fatty acids esterification into biodiesel-like compounds. Remarkably, the synergistic hydrophilic/hydrophobic effect of pyridinium and trifluoroacetate ionic liquid in the well-ordered channels of PMO-Py-IL nanomaterial enhanced the activity toward sustainable biodiesel-like esters production. More importantly, PMO-Py-IL nanocatalyst also exhibited an exceptional activity and stability. The catalyst could be easily separated to reuse at least in ten reactions runs preserving almost intact its catalytic activity under otherwise identical conditions to those employed for the fresh catalysts.
- Luque, Rafael,Rajabi, Fatemeh
-
-
- Sulfonated Hyper-cross-linked Porous Polyacetylene Networks as Versatile Heterogeneous Acid Catalysts
-
Two highly sulfonated micro/mesoporous polymers, P(1,3-DEB)-SO3H and P(1,4-DEB)-SO3H, with permanent porosity, the specific surface area about 550 m2 ? g?1 and the content of SO3H groups of 2.7 mmol ? g?1 were prepared as new acid Porous Polymer Catalysts, PPCs. The PPCs were achieved by easy sulfonation of parent hyper-cross-linked micro/mesoporous polyacetylene-type networks resulting from a chain-growth homopolymerization of 1,3- and 1,4-diethynylbenzenes. New PPCs are reported as highly active and reusable heterogeneous catalysts of esterification of fatty acids with methanol and ethanol, Prins cyclization of aldehydes with isoprenol and intramolecular Prins cyclization of citronellal to isopulegol. The catalytic activity of the micro/mesoporous PPCs (TON values up to 522 mol ? mol?1) was higher than that of commercial polymer-based heterogeneous catalyst Amberlyst 15 possessing gel texture without permanent pores and that of p-toluenesulfonic acid applied as a homogeneous catalyst.
- Sekerová, Lada,B?ezinová, Pavlína,Do, Thuy Tran,Vysko?ilová, Eli?ka,Krupka, Ji?í,?erveny, Libor,Havelková, Lucie,Bashta, Bogdana,Sedlá?ek, Jan
-
p. 1075 - 1084
(2020/01/03)
-
- Aldehydes as potential acylating reagents for oxidative esterification by inorganic ligand-supported iron catalysis
-
The oxidative esterification of various aldehydes with alcohols could be achieved by a heterogeneous iron(iii) catalyst supported on a ring-like POM inorganic ligand under mild conditions, affording the corresponding esters, including several drug molecules and natural products, in high yields. ESI-MS and control experiments demonstrated that POM-FeV(O) was the active catalytic species and the plausible mechanism was presented. More importantly, the 6th run of the iron catalyst recycles shows only a slight decrease in the yield.
- Yu, Han,Wang, Jingjing,Wu, Zhikang,Zhao, Qixin,Dan, Demin,Han, Sheng,Tang, Jiangjiang,Wei, Yongge
-
supporting information
p. 4550 - 4554
(2019/08/21)
-
- Detection and identification of complex oxylipins in meadow buttercup (Ranunculus acris) leaves
-
Screening of linolipins, i.e. galactolipids containing esterified residues of divinyl ether oxylipins, in the leaves of several higher plants revealed the presence of these complex oxylipins in the meadow buttercup leaves. The rapid accumulation of linoli
- Chechetkin, Ivan R.,Blufard, Alexander S.,Yarin, Andrey Y.,Fedina, Evgenia O.,Khairutdinov, Bulat I.,Grechkin, Alexander N.
-
-
- Method for synthesis of long-chain fatty acid ester derivative
-
The invention relates to a method for synthesis of a long-chain fatty acid ester derivative. Specifically, a hydrochloride of glycine methyl ester or glycine ethyl ester is used as a catalyst to catalyze the esterification reaction of long-chain fatty acid. The method includes: subjecting alcohol and long-chain fatty acid to esterification reaction under the action of the catalyst at certain temperature condition, then conducting extraction and precipitation with ethyl acetate, performing flushing with a sodium chloride aqueous solution for purification. A hydrochloride of glycine methyl esteror glycine ethyl ester is adopted as the catalyst, which belongs to a green catalyst, is the development trend of modern chemistry, has the characteristics of no corrosion to the reaction kettle, lowprice, no toxicity and the like, and is suitable for use as a catalyst to produce palmitate and laurate perfume raw materials.
- -
-
Paragraph 0027-0028
(2020/01/12)
-
- Sulfonic acid-functionalized organic knitted porous polyaromatic microspheres as heterogeneous catalysts for biodiesel production
-
The use of renewable energy sources decreases the consequences of greenhouse gas emission from fossil fuels. Biodiesel, an easily burning and biodegradable fuel, is an alternative to conventional diesel fuel. The esterification of long-chain fatty acids and transesterification of triglycerides are two major reactions widely used to convert vegetable oils or animal fats into biodiesel. As solid acid catalysts are considered promising candidates for biodiesel production, we have synthesized a series of organic knitted porous polyaromatics (OPPs) using pyrene, anthracene, and naphthalene as monomers via Friedel-Crafts alkylation, followed by crosslinking reactions. The resultant polymers showed good surface morphology, stability and swelling property, high capacity for functionalization due to the unreacted bromomethyl groups on the surface, and excellent hydrophobicity. The sulfonated polymer microspheres obtained by the surface sulfonation showed good surface acidity; thus, they can be employed as heterogeneous solid acid catalysts for the esterification of long-chain fatty acids and transesterification of triglycerides, and they are reusable without any leaching of functional groups.
- Varyambath, Anuraj,Kim, Mi-Ra,Kim, Il
-
p. 12745 - 12753
(2018/08/04)
-
- Clean and Green Procedure for the Synthesis of Biodiesel from the Esterification of Free Fatty Acids and Alcohol Catalyzed by 6-O-(sulfobutyl)-Β-cyclodextrin
-
The catalyst of 6-O-(sulfobutyl)-β-cyclodextrin (SB-CD) is renewable, non-toxic, environmentally benign and biocompatible, which could be used as efficient and recyclable catalyst for the synthesis of biodiesel from free long-chain fatty acids with low-chain alcohols as substrates. The reaction was accomplished at 60°C for 1.5 h, while the products were separated from the catalyst system by liquid/liquid at room temperature with good conversion of 91–98%. The catalyst can be reused for 10 times. The novel and clean procedure offers advantages including short reaction time, good conversion, operational simplicity, and environmentally benign characteristics.
- Zhang, Guangqing,He, Leqin,Yuan, Mingxia,Li, Hui,Chang, Tao,Qin, Shenjun
-
p. 1123 - 1128
(2018/10/24)
-
- Dammarane triterpenoids from Carnauba, Copernicia prunifera (Miller) H. E. Moore (Arecaceae), wax
-
Phytochemical investigation from carnauba (Copernicia prunifera) wax led to the identification of sixteen dammarane–type triterpenes, including thirteen new characterized as: (24R*)-methyldammara-20,25-dien-3α-ol and a mixture of alkyl (24R*)-methyldammar-25-en-20-ol-3β-carboxylates, together with three previously described triterpenes: carnaubadiol, (24R*)-methyldammara-20,25-dien-3β-ol and (24R*)-24-methyldammara-20,25-dien-3-one. Moreover, four fatty alcohols (eicosanol, docosanol, tetracosanol and hexacosanol) as well as four sterols (cholesterol, campesterol, stigmasterol, and sitosterol) were also obtained. These compounds were isolated using classical chromatographic methods and their structures were determined by spectroscopic and chemical methods.
- De Almeida, Buana C.,Araújo, Bruno Q.,Barros, Elcio D. S.,Freitas, Samya D. L.,Maciel, Dayany S. A.,Ferreira, Ari J. S.,Guadagnin, Rafael C.,Vieira, Gerardo M.,Lago, Jo?o H. G.,Chaves, Mariana H.
-
p. 1371 - 1376
(2017/07/13)
-
- Conversion of alcohols to alkyl esters and carboxylic acids using heterogeneous palladium-based catalysts
-
Disclosed are methods for synthesizing an ester or a carboxylic acid from an organic alcohol. To form the ester one reacts, in the presence of oxygen gas, the alcohol with methanol or ethanol. This reaction occurs in the presence of a catalyst comprising palladium and a co-catalyst comprising bismuth, tellurium, lead, cerium, titanium, zinc and/or niobium (most preferably at least bismuth and tellurium). Alternatively that catalyst can be used to generate an acid from that alcohol, when water is also added to the reaction mix.
- -
-
-
- Methanolysis of Jatropha curcas oil using K2CO3/CaO as a solid base catalyst
-
Biodiesel, fatty acid methyl ester produced by the transesterification of vegetable oil with methanol, is a promising alternative to petroleum-based diesel fuel. In the present study, the methanolysis of high free fatty acid (FFA) Jatropha curcas oil in a transesterification reaction using K 2 CO 3 /CaO solid base catalyst was studied. The various reaction parameters in the transesterification reaction were also discussed. The catalyst was characterized by means of Fourier transform infrared, X-ray diffraction, temperature programmed desorption of CO 2, scanning electron microscopy, particle size analyzer, true density, and surface area analyzer. The optimum conversion of jatropha oil was 92% when the transesterification reaction was carried out at 70? C with 10:1 molar ratio of methanol to oil at reaction time of 3 h and catalyst amount of 6 wt%. The efficiency of catalysts in the methanolysis of jatropha oil was also investigated.
- Sahu, Gajanan,Saha, Sujan,Datta, Sudipta,Chavan, Prakash,Naik, Satyanarayan
-
p. 845 - 861
(2018/01/12)
-
- Metathesis of renewable polyene feedstocks – Indirect evidences of the formation of catalytically active ruthenium allylidene species
-
Cross-metathesis (CM) of conjugated polyenes, such as 1,6-diphenyl-1,3,5-hexatriene (1) and α-eleostearic acid methyl ester (2) with several olefins, including 1-hexene, dimethyl maleate and cis-stilbene as model compounds has been carried out using (1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene)-dichloro(o-isopropoxyphenylmethylene)ruthenium (Hoveyda-Grubbs 2nd generation, HG2) catalyst. The feasibility of these reactions is demonstrated by the observed high conversions and reasonable yields. Thus, regardless of the relatively low electron density, =CH–CH= conjugated units of molecules, including compound 2 as a sustainable, non-foodstuff source, can be utilized as building blocks for the synthesis of various value-added chemicals via olefin metathesis. DFT-studies and the product spectrum of the self-metathesis of 1,6-diphenyl-1,3,5-hexatriene suggest that a Ru η1-allylidene complex is the active species in the reaction.
- Kovács, Ervin,Sághy, Péter,Turczel, Gábor,Tóth, Imre,Lendvay, Gy?rgy,Domján, Attila,Anastas, Paul T.,Tuba, Róbert
-
supporting information
p. 213 - 217
(2017/09/12)
-
- Inflammation Modulatory Phorbol Esters from the Seeds of Aquilaria malaccensis
-
The tree Aquilaria malaccensis is a valuable source of agarwood, which is used in herbal medicinal preparations. Phytochemical research on A. malaccensis seeds has led to the isolation of four new phorbol esters (1-4), two known phorbol esters (5, isolated from Nature for the first time, and 6), and two known glycerides (7 and 8). The structures of these isolates were elucidated by means of spectroscopic data interpretation. The inflammation-modulatory activities of the isolates on elastase release and superoxide anion generation in human neutrophils were evaluated. Interestingly, phorbol esters 1, 5, and 6 showed potent inhibitory activity on elastase release in human neutrophils, with IC50 values of 2.7, 0.8, and 2.1 μM, respectively. All isolated phorbol esters exerted enhancing activity on superoxide anion generation. The results indicated that phorbol esters may play a bilateral modulatory role in the processes of inflammation. In addition, the compounds were evaluated for their cytotoxic properties against HepG2 (hepatoma), MDA-MB-231 (breast), and A549 (lung) cancer cells, but all compounds were inactive for all cell lines used (IC50 > 10 μM).
- Wagh, Vitthal D.,Korinek, Michal,Lo, I-Wen,Hsu, Yu-Ming,Chen, Shu-Li,Hsu, Hsue-Yin,Hwang, Tsong-Long,Wu, Yang-Chang,Chen, Bing-Hung,Cheng, Yuan-Bin,Chang, Fang-Rong
-
p. 1421 - 1427
(2017/06/01)
-
- CERAMIDE DERIVATIVES AS ANTICANCER AGENTS
-
The invention provides a compound of formula (I): (I) wherein R1-R4 have any of the values defined in the specification, as well as compositions comprising a compound of formula (I) and methods for treating diseases (e.g. cancer).
- -
-
Page/Page column 21
(2017/02/09)
-
- Surfactant-like Br?nsted acidic ionic liquid as an efficient catalyst for selective Mannich reaction and biodiesel production in water
-
Abstract: The current study deals with the applications of a surfactant-like Br?nsted acidic ionic liquid (IL) 1-dodecyl-3-methylimidazolium hydrogen sulfate ([DMIm]HSO4) for Mannich reaction at room temperature. The reaction was efficiently preceded in water as solvent without using any harmful and expensive organic additives. Our findings showed that the reaction is selective for cyclohexanone and no Mannich product was observed when cyclopentanone was used as starting material. Density functional theory (DFT) calculations were performed to provide an evidence about the nature of reactivity of the cyclohexanone/cyclopentanone. The activity of the catalyst was also tested for biodiesel production of fatty acids with methanol and ethanol at mild thermal condition without applying additional water removal steps such as using additives or performing special methodologies like azeotropic distillation. In both reactions, the IL can be recycled and reused several times with relatively constant efficiency. Graphical Abstract: [Figure not available: see fulltext.]
- Vafaeezadeh, Majid,Karbalaie-Reza, Mina,Hashemi, Mohammad Mahmoodi,Soleimany, Kasra Qasempour
-
p. 907 - 914
(2017/02/26)
-
- Synthesis and antimicrobial studies of 5-n-alkyl-1,3,4-oxadiazole-2-thiol derivatives from fatty acids
-
The novel 5-N-alkyl-1,3,4-oxadiazole-2-thiol derivatives have been synthesized by esterification of fatty acid followed by reaction the ester with hydrazine hydrate. The acid hydrazide was converted to 1,3,4-oxadiazole by ring closure mechanism. The synthesized compounds have been characterized by physical (melting point and TLC) and spectral (IR, 1H NMR and mass) data. All the compounds were screened for their antimicrobial activity. The compounds 3F1 & 3F4 showed good inhibition activity against all four types of bacteria; while compound 3F2 & 3F3 shown moderate activity.
- Naga Sudha,Yella Subbaiah,Srikanth,Venkata Ramana Reddy,Sneha Latha,Vijaya Lakshmi
-
p. 2369 - 2371
(2017/10/31)
-
- Mesoporous Ag1(NH4)2PW12O40 heteropolyacids as effective catalysts for the esterification of oleic acid to biodiesel
-
Mesoporous Ag1(NH4)2PW12O40 (AgN-PW) was developed by co-doping silver and ammonium ions into phosphotungstic acid as an efficient and stable catalyst for free fatty acid esterification, and its physicochemical properties were derived from X-ray diffraction (XRD), thermogravimetric (TG) analysis, Fourier transform infrared (FT-IR) spectra, N2 adsorption-desorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The final catalyst showed a typical Keggin structure of heteropoly acids. This solid acid exhibited remarkable catalytic activity (nearly 100% conversion) in the esterification of oleic acid with methanol for biodiesel production under optimum synthesis conditions. Furthermore, due to the high activity presented in various esterifications of free fatty acids and non-edible oils with high acid values, the mesoporous AgN-PW material was proven to be an environmentally friendly catalyst for industrial biodiesel production.
- Zhang, Qiu-Yun,Wei, Fang-Fang,Li, Qian,Huang, Jin-Shu,Feng, Yun-Mei,Zhang, Yu-Tao
-
p. 51090 - 51095
(2017/11/16)
-
- Lipophilic gold(I) complexes with 1,3,4-oxadiazol-2-thione or 1,3-thiazolidine-2-thione moieties: synthesis and their cytotoxic and antimicrobial activities
-
Novel lipophilic gold(I) complexes containing 1,3,4-oxadiazol-2-thione or 1,3-thiazolidine-2-thione derivatives were synthesized and characterized by IR, high resolution mass spectrometry, and 1H, 13C 31P NMR. The cytotoxicity of the compounds was evaluated considering cisplatin and/or auranofin as reference in different tumor cell lines: colon cancer (CT26WT), metastatic skin melanoma (B16F10), breast adenocarcinoma (MCF-7), cervical carcinoma (HeLa), glioblastoma (M059?J). Normal human lung fibroblasts (GM07492-A) and kidney normal cell (BHK-21) were also evaluated. The gold(I) complexes were more active than their respective free ligands and cisplatin. Furthermore, antibacterial activity was evaluated against Gram-positive bacteria Staphylococcus aureus ATCC 25213, Staphylococcus epidermidis ATCC 12228 and Gram-negative bacteria Escherichia coli ATCC 11229 and Pseudomonas aeruginosa ATCC 27853 and expressed as the minimum inhibitory concentration (MIC). The complexes exhibited lower MIC values when compared to the ligands and chloramphenicol against Gram-positive bacteria and Gram-negative bacteria. Escherichia coli was sensitive one to the action of gold(I) complexes.
- de Almeida, Angelina Maria,de Oliveira, Bruno Assis,de Castro, Pedro P?ssa,de Mendon?a, Camille Carvalho,Furtado, Ricardo Andrade,Nicolella, Heloiza Diniz,da Silva, Vania Lúcia,Diniz, Cláudio Galuppo,Tavares, Denise Crispim,Silva, Heveline,de Almeida, Mauro Vieira
-
p. 841 - 857
(2017/10/07)
-
- Separation of PALMITIC acid from over used oil for production of heterogeneous organic derivatives of potential biological activities
-
PALMITIC acid was extracted from Over-used cooking oil where oil was filtered off, then it was hydrolyzed with distilled water in high pressure reactor at 250°C and 2 MPa to produce glycerol and mixture of fatty acids. Fatty acids mixture was cooled at 7°C in order to precipitate all saturated fatty acids, which were then filtered off, Palmitic acid was extracted from this mixture by means of supercritical CO2 extractor at 35.0 MPa and 55°C, followed by its methylation and confirmation by GC mass. Then it was used as precursor for production of a different heterocyclic compounds which were then tested for their antimicrobial activities. Thus the long-chain methyl palmitate was interacted with hydrazine hydrate to produce the corresponding acid hydrazide (2), and then it was treated with phenyl isothiocyanate, furnished the corresponding thiosemicarbazide 4. The later was reacted with ethyl chloro(arylhydrazono) acetate 5a-b in dimethylformamide, in the presence of triethylamine, afforded thiadiazole derivatives 7a-b. A solution of thiosemicarbazide 4 in ethanol was interacted with the a-haloketones 9 in the presence of triethylamine, produced the parallel thiadiazine 12. The structure elucidation of all synthesized compounds is based on the elemental analysis and spectral data (IR, 1H NMR, 13C NMR and MS).
- Soliman, Hanaa M.,El-Shattory
-
p. 591 - 600
(2019/01/30)
-
- Cytotoxic ceramides from Antipathes dichotoma
-
A new ceramid (2S?, 3S?, 4E, 8E)-2N-[hexadecanoyl]-4 (E), 8 (E)-docosadiene-1, 3-diol (1), along with the previously identified one (2S?, 3S?, 4E, 8E)-2N-[tetradecanoyl]-4 (E), 8 (E)-icosadiene-1, 3-diol (2), and the dihydroxy steroid, 24-methyl-cholest-5 (E), 22 (E)-dien-3β,7α-diol (3) were identified from the Red Sea black coral Antipathies dichotoma. Extensive spectroscopic data 1D and 2D- NMR, UV, IR and MS were the bases for structure elucidation of all isolated metabolites. The spectral values for compound 3 are reported here for the first time. All compounds have been estimated toward their cytotoxicity, against several cancer cell lines; HepG2, WI 38, VERO and MCF-7. They showed strong to moderate cytotoxic activities. Compounds 1 and 2 displayed strong antiproliferative activities against HepG2 and MCF-7 cell lines. 3 displayed almost weak activity towards all investigated cell lines.
- Alarif, Walied Mamed,Al-Lihaibi, Sultan Samran,Ayyad, Seif-Eldin Nasr,Ghandourah, Mohamed Ali,Orif, Mohamed Ibrahim,Basaif, Salim Ahmed,Abdel-Lateff, Ahmed
-
p. 553 - 557
(2016/08/26)
-
- A new lupane-type triterpenoid fatty acid ester and other isolates from Ophiorrhiza shendurunii
-
A new pentacyclic triterpenoid fatty acid ester, lupan-20-ol-3(β)-yl hexadecanoate (1), together with lupan-20-ol-3(β)-yl acetate (2), olean-18-en-3(β)-yl hexadecanoate (3), dotriacontanoic acid (4), stigmasterol (5), rubiadin (6), nonadecanoic acid (7), palmitic acid (8) and camptothecin (9) were isolated from the hexane and chloroform extracts of Ophiorrhiza shendurunii from South India. Structures of the isolates were determined by1H,13C,13C DEPT,1H–1H COSY, HMBC, HSQC, NOESY NMR, FT-IR, DART-MS, ESI-MS, alkaline hydrolysis, derivatisation, GC–MS and HPTLC analyses. O. shendurunii hexane and chloroform extracts showed significant activities against Candida albicans and Fusarium oxysporum. Compounds 1 to 3 showed only moderate antiyeast/antifungal activities.
- Rajan, Renjith,Venkataraman, Ramaswamy,Baby, Sabulal
-
p. 2197 - 2203
(2016/09/20)
-
- Efficient and stable PS-SO3H/SiO2 hollow nanospheres with tunable surface properties for acid catalyzed reactions
-
Facile synthesis of hybrid solid acids with finely engineered surface properties was successfully realized via sulfonation of polystyrene (PS) dispersed in nanopores of silica hollow nanosphere modified with different organic group. It was found that octyl or perfluorinated octyl could efficiently increase the surface hydrophobicity of the hybrid solid acids. Benefited from the facile adjustability of the surface properties, the catalytic performance of the solid acids could be readily improved in both the esterification of lauric acid with ethanol and the transterification between tripalmitin and methanol. The solid acid modified with perfluorinated octyl shows even higher activity than liquid sulfuric acid in the transesterification reaction. The octyl group incorporated in the silica shell could also prevent the leaching of PS-SO3H during the catalytic process.
- Chen, Jingjing,Chen, Jian,Zhang, Xiaomin,Gao, Jinsuo,Yang, Qihua
-
-
