112-39-0Relevant articles and documents
A new oxo-sterol derivative from the rhizomes of Costus speciosus
Kumar, Ashish,Chand, Gopi,Agnihotri, Vijai K.
, p. 18 - 22 (2018)
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.
The major zeaxanthin dipalmitate derivatives from wolfberry
Long, Jia-Tang,Fan, Hong-Xia,Zhou, Zheng-Qun,Sun, Wan-Yang,Li, Qing-Wen,Wang, Ying,Ma, Min,Gao, Hao,Zhi, Hui
, p. 746 - 753 (2020)
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.
Efficient conversion of triacylglycerols and fatty acids to biodiesel in a microwave reactor using metal triflate catalysts
Socha, Aaron M.,Sello, Jason K.
, p. 4753 - 4756 (2010)
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.
Magnetically separable porous carbon nanospheres as solid acid catalysts
Chang, Binbin,Tian, Yanlong,Shi, Weiwei,Liu, Jiyang,Xi, Fengna,Dong, Xiaoping
, p. 20999 - 21006 (2013)
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.
A rapid and sensitive profiling of free fatty acids using liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) after chemical derivatization
Mok, Hyuck Jun,Lee, Jae Won,Bandu, Raju,Kang, Hong Seok,Kim, Kyun-Hwan,Kim, Kwang Pyo
, p. 32130 - 32139 (2016)
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.
Catalytic esterification of fatty acids using solid acid catalysts generated from biochar and activated carbon
Kastner, James R.,Miller, Joby,Geller, Daniel P.,Locklin, Jason,Keith, Lawrence H.,Johnson, Tyson
, p. 122 - 132 (2012)
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.
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
Chehrouri, Manel,Othman, Adil A.,Jiménez-Cecilia, Samuel,Moreno-Cabrerizo, Cristina,Sansano, José M.
, p. 1301 - 1307 (2019)
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.
Potassium 2-methoxy-4-vinylphenolate: A novel hit exhibiting quorum-sensing inhibition in: Pseudomonas aeruginosa via LasIR/RhlIR circuitry
Shah, Mayank D.,Kharkar, Prashant S.,Sahu, Niteshkumar U.,Peerzada, Zoya,Desai, Krutika B.
, p. 40228 - 40239 (2019)
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.
Biodiesel production by acid catalysis with heteropolyacids supported on activated carbon fibers
Alca?iz-Monge, Juan,Trautwein, Guido,Marco-Lozar, Juan Pablo
, p. 432 - 441 (2013)
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.
A solvent-free, one-step synthesis of sulfonic acid group-functionalized mesoporous organosilica with ultra-high acid concentrations and excellent catalytic activities
Wu, Qin,Liu, Fujian,Yi, Xianfeng,Zou, Yongcun,Jiang, Lilong
, p. 1020 - 1030 (2018)
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.
