- IRISTECTORENE B, A MONOCYCLIC TRITERPENE ESTER FROM IRIS TECTORUM
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A monocyclic triterpene ester, iristectorene B, has been isolated from the seeds of Iris tectorum.On the basis of spectroscopic methods and chemical evidence, the ester was shown to be 3--2,3-dimethyl-6-(1-methyl-2-oxoethylidene)cyclohexyl>propyl tetradecanoate and its stereochemistry was also clerified.
- Seki, Katsura,Tomihari, Toshiya,Haga, Kazuo,Kaneko, Ryohei
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- Steroids and ceramide from the stem bark of Odyendyea gabonensis
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Two new steroids, 22E, 24R-stigmast-22-ene-3,6,11-trione (1) and 22E, 24R-3-acetylstigmasta-5,22-diene-7,11-dione (2), and one new ceramide, (2S,3S,4R,5R) N-(1,3,4,5-tetrahydroxyundecan-2-yl)tetradecanamide (7), together with eleven known compounds were isolated from the CH2Cl2 extract of the stem bark of Odyendyea gabonensis. The structures of all compounds were determined by comprehensive analyses of their 1D and 2D NMR, mass spectral (EI and ESI) data, chemical reactions, and comparison with previously known analogs. Pure compounds were tested for their activity against the bacteria Bacillus subtilis, Staphylococcus aureus and Escherichia coli, the fungi Mucor miehei and Candida albicans, and the plant pathogen oomycetes Aphanomyces cochlioides, Pythium ultimum and Rhizoctonia solani using the paper disk agar diffusion assay. For active compounds, MICs were determined by the broth microdilution assay. Cytotoxic activity against the human lung adenocarcinoma cell line A 549 was evaluated by the MTT assay. All compounds delivered low to missing antimicrobial activities in the agar diffusion assay and MICs > 1 mg mL-1. The alkaloids 10 and 11 displayed cytotoxic activity against the human lung adenocarcinoma cell line A549 with IC 50 2.5 and 4.5 μm respectively.
- Happi, Emmanuel Ngeufa,Fannang, Simone Veronique,Fomani, Marie,Donkwe, Suzye Mireille Moladje,Nicaise, Nkoungou Yomzak Carine,Wansi, Jean Duplex,Sewald, Norbert
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- Antibacterial sphingolipid and steroids from the black coral Antipathes dichotoma
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From the black coral Antipathies dichotoma, a sphingolipid (2S*,3S*,4E,8E)-2N-[tetradecanoyl]-4(E),8(E)-icosadiene-1, 3-diol (1) and a steroid (22E)-methylcholesta-5,22-diene-1 α,3 β,7 α-triol (2) were isolated. Other known compounds, 3β,7 α-dihydroxy-cholest-5-ene (3) (22E,24S),5α,8α-epidioxy-24- methylcholesta-6,22-dien-3β-ol (4) and (22E,24S),5α,8α- epidioxy-24-methylcholesta-6,9(11),22-trien-3β-ol (5). The structures were established on the basis of NMR spectroscopic analysis and comparison with literature. The antibacterial activity of five compounds was evaluated.
- Al-Lihaibi, Sultan Samran,Ayyad, Seif-Eldin Nasr,Shaher, Fekry,Alarif, Walied Mohamed
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- ZWITTERIONIC CATALYSTS FOR (TRANS)ESTERIFICATION: APPLICATION IN FLUOROINDOLE-DERIVATIVES AND BIODIESEL SYNTHESIS
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An amide/iminium zwitterion catalyst has a catalyst pocket size that promotes transesterification and dehydrative esterification. The amide/iminium zwitterions are easily prepared by reacting aziridines with aminopyridines. The reaction can be applied a wide variety of esterification processes including the large-scale synthesis of biodiesel. The amide/iminium zwitterions allow the avoidance of strongly basic or acidic condition and avoidance of metal contamination in the products. Reactions are carried out at ambient or only modestly elevated temperatures. The amide/iminium zwitterion catalyst is easily recycled and reactions proceed in high to quantitative yields.
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Paragraph 0010; 0026
(2021/01/29)
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- Preparation method of carboxylic ester compound
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The invention relates to a preparation method of a carboxylic ester compound, which comprises the following steps: reacting carboxylic acid with methanol in air under the catalysis of nitrite to obtain an ester compound, the preparation method disclosed by the invention has the advantages of rich raw material sources, cheap and easily available catalyst, mild reaction conditions, simplicity and convenience in operation and the like, a series of fatty carboxylic acids can be modified with high yield, and particularly, the traditional esterification method is generally not suitable for esterification of drug molecules. By utilizing the method, a series of known drug molecules can be modified, so that a shortcut is provided for discovering new drug molecules.
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Paragraph 0034-0035
(2021/03/30)
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- Green Esterification of Carboxylic Acids Promoted by tert-Butyl Nitrite
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In this work, the green esterification of carboxylic acids promoted by tert-butyl nitrite has been well developed. This transformation is compatible with a broad range of substrates and exhibits excellent functional group tolerance. Various drugs and substituted amino acids are applicable to this reaction under near neutral conditions, with good to excellent yields.
- Cheng, Xionglve,Jiang, Gangzhong,Li, Xingxing,Tao, Suyan,Wan, Xiaobing,Zhao, Yanwei,Zheng, Yonggao
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supporting information
p. 2713 - 2718
(2021/06/25)
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- Tunable aryl imidazolium ionic liquids (TAIILs) as environmentally benign catalysts for the esterification of fatty acids to biodiesel fuel
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Herein, we describe the synthesis of tunable aryl imidazolium ionic liquid catalysts and tested for esterification of fatty acids to biodiesel. In this work, six tunable aryl imidazolium ionic liquids (TAIILs) 1a-1f were prepared. These ionic liquids were used as the economical and reusable catalysts for the synthesis of biodiesel fuels. The reaction has been preceded in a monophase at 80 °C for 4 h, after which the product was separated from the catalyst system by a simple liquid/liquid phase separation at room temperature with excellent yields. With the simple post-process, the catalyst is reusable at least 6 times. This novel method offers a short reaction time, good yields, and environmentally benign characteristics.
- Ho, Wen-Yueh,Lin, Wesley,Lin, Yi-Jyun,Luo, Shun-Yuan,Pantawane, Amit,Su, Po-Fang,Thul, Mayur,Tseng, Shao-An,Wu, Hsin-Ru
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- Novel synthesized microporous ionic polymer applications in transesterification of Jatropha curcas seed oil with short Chain alcohol
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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
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- Highly ordered mesoporous functionalized pyridinium protic ionic liquids framework as efficient system in esterification reactions for biofuels production
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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
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- Sulfonated Hyper-cross-linked Porous Polyacetylene Networks as Versatile Heterogeneous Acid Catalysts
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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
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p. 1075 - 1084
(2020/01/03)
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- Ruthenium-catalyzed hydrogenation of CO2as a route to methyl esters for use as biofuels or fine chemicals
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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
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p. 6766 - 6774
(2020/08/25)
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- 1,3-Dibromo-5,5-dimethylhydantoin as a Precatalyst for Activation of Carbonyl Functionality
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Activation of carbonyl moiety is one of the most rudimentary approaches in organic synthesis and is crucial for a plethora of industrial-scale condensation reactions. In esterification and aldol condensation, which represent two of the most important reactions, the susceptibility of the carbonyl group to nucleophile attack allows the construction of a variety of useful organic compounds. In this context, there is a constant need for development of and improvement in the methods for addition-elimination reactions via activation of carbonyl functionality. In this paper, an advanced methodology for the direct esterification of carboxylic acids and alcohols, and for aldol condensation of aldehydes using widely available, inexpensive, and metal-free 1,3-dibromo-5,5-dimethylhydantoin under neat reaction conditions is reported. The method is air- and moisture-tolerant, allowing simple synthetic and isolation procedures for both reactions presented in this paper. The reaction pathway for esterification is proposed and a scale-up of certain industrially important derivatives is performed.
- ?ebular, Klara,Bo?i?, Bojan ?.,Stavber, Stojan
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supporting information
(2019/08/01)
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- Medium-chain fatty acids from Eugenia winzerlingii leaves causing insect settling deterrent, nematicidal, and phytotoxic effects
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Eugenia winzerlingii (Myrtaceae) is an endemic plant from the Yucatan peninsula. Its organic extracts and fractions from leaves have been tested on two phloem-feeding insects, Bemisia tabaci and Myzus persicae, on two plant parasitic nematodes, Meloidogyne incognita and Meloidogyne javanica, and phytotoxicity on Lolium perenne and Solanum lycopersicum. Results showed that both the hexane extract and the ethyl acetate extract, as well as the fractions, have strong antifeedant and nematicidal effects. Gas chromatography-mass spectrometry analyses of methylated active fractions revealed the presence of a mixture of fatty acids. Authentic standards of detected fatty acids and methyl and ethyl derivatives were tested on target organisms. The most active compounds were decanoic, undecanoic, and dodecanoic acids. Methyl and ethyl ester derivatives had lower effects in comparison with free fatty acids. Dose-response experiments showed that undecanoic acid was the most potent compound with EC50 values of 21 and 6 nmol/cm2 for M. persicae and B. tabaci, respectively, and 192 and 64 nmol for M. incognita and M. javanica, respectively. In a phytotoxicity assay, medium-chain fatty acids caused a decrease of 38-52% in root length and 50-60% in leaf length of L. perenne, but no effects were observed on S. lycopersicum. This study highlights the importance of the genus Eugenia as a source of bioactive metabolites for plant pest management.
- Cruz-Estrada, Angel,Ruiz-Sánchez, Esaú,Cristóbal-Alejo, Jairo,González-Coloma, Azucena,Andrés, María Fe,Gamboa-Angulo, Marcela
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- Amide/Iminium Zwitterionic Catalysts for (Trans)esterification: Application in Biodiesel Synthesis
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A class of zwitterionic organocatalysts based on an amide anion/iminium cation charge pair has been developed. The zwitterions are easily prepared by reacting aziridines with aminopyridines. They are catalytically applicable to transesterifications and dehydrative esterifications. Mechanistic studies reveal that the amide anion and iminium cation work synergistically in activating the reaction partners, with the iminium cationic moiety interacting with the carbonyl substrates through nonclassical hydrogen bonding. The reaction can be applied to large-scale synthesis of biodiesel under mild conditions.
- Lam, Ying-Pong,Ng, Wing-Hin,Tan, Fei,Tse, Ying-Lung Steve,Wang, Xinyan,Yeung, Ying-Yeung
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p. 8083 - 8092
(2019/08/26)
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- Sulfonic acid-functionalized organic knitted porous polyaromatic microspheres as heterogeneous catalysts for biodiesel production
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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
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p. 12745 - 12753
(2018/08/04)
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- Metathesis of renewable polyene feedstocks – Indirect evidences of the formation of catalytically active ruthenium allylidene species
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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
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supporting information
p. 213 - 217
(2017/09/12)
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- Methods for production of fatty acid alkanolamides (FAAAs) from microalgae biomass
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Provided herein are methods for fatty acid alkanolamide (FAAA) synthesis and isolation from lipid-containing algal biomass, and the products of such methods.
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Page/Page column 11; 12
(2017/02/28)
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- Heterogeneous esterification of fatty acids with methanol catalyzed by Lewis acidic organozirconium complexes with Keggin-type mono-aluminum-substituted polyoxotungstates
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Two Lewis acidic organozirconium complexes with α-Keggin-type mono-aluminum-substituted polyoxotungstates, [(n-C4H9)4N]6[α-PW11Al(OH)O39ZrCp2]2 (Cp = η5-C5H5?) (TBA-P-Al-Zr) and [(n-C4H9)4N]6[α-SiW11Al(OH)2O38ZrCp2]2·2H2O (TBA-Si-Al-Zr), were used as heterogeneous catalysts for the esterification of various fatty acids with methanol. For the esterification of linoleic acid at 80 ± 2 °C, TBA-P-Al-Zr exhibited 83% conversion after 6 h, approximately six times higher than that of TBA-Si-Al-Zr. TBA-P-Al-Zr also exhibited 69–90% conversion for the esterification of oleic acid, palmitic acid, myristic acid, and lauric acid with methanol at 80 ± 2 °C.
- Kato, Chika Nozaki,Ogasawara, Tsukasa,Kondo, Akari,Kato, Daichi
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- Mesoporous Ag1(NH4)2PW12O40 heteropolyacids as effective catalysts for the esterification of oleic acid to biodiesel
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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
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p. 51090 - 51095
(2017/11/16)
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- 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
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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
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p. 841 - 857
(2017/10/07)
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- New cytotoxic secondary metabolites from marine bryozoan Cryptosula pallasiana
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A new sterol, (23R)-methoxycholest-5,24-dien-3β-ol (1), two new ceramides, (2S,3R,4E,8E)- 2-(tetradecanoylamino)-4,8-octadecadien-l,3-diol (6) and (2S,3R,2′R,4E,8E)-2-(tetradecanoylamino)- 4,8-octadecadien-l,3,2′-triol (7), together with three known sterols (2-4), a lactone (5) and two ceramides (8,9), were isolated from the marine bryozoan Cryptosula pallasiana, collected at Huang Island of China. The structures of the new compounds were elucidated by extensive spectroscopic analyses, chemical methods and quantum electronic circular dichroism (ECD) calculations. Among the isolated compounds, sterol 1 possessed a rare side chain with a methoxy group at C-23, and a double bond between C-24 and C-25. Ceramides 6 and 7 possessed 14 carbons in their long-chain fatty acid base (FAB), which were different from the normal ceramides with 16 carbons in the FAB. Moreover, compounds 5 and 8 were isolated for the first time from marine bryozoans. Compounds 1-9 were evaluated for their cytotoxicity against human tumor cell lines HL-60, Hep-G2 and SGC-7901. The results showed that lactone 5 appears to have strong cytotoxicity against the test tumor cell lines, with IC50 values from 4.12 μM to 7.32 μM, and sterol 1 displayed moderate cytotoxicity with IC50 values between 12.34 μM and 18.37 μM, while ceramides 6-9 showed weak cytotoxicity with IC50 ranging from 21.13 μM to 58.15 μM.
- Tian, Xiang-Rong,Gao, Yan-Qing,Tian, Xiao-Lin,Li, Jiao,Tang, Hai-Feng,Li, Yu-Shan,Lin, Hou-Wen,Ma, Zhi-Qing
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- CERAMIDE DERIVATIVES AS ANTICANCER AGENTS
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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).
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Page/Page column 21; 23; 24
(2017/02/09)
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- Sulfonated porous organic polymer as a highly efficient catalyst for the synthesis of biodiesel at room temperature
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A new functionalized porous organic polymer bearing sulfonic acid groups (PDVTA-SO3H) at the pore surface with high surface area (SBET = 406 m2 g-1) and Bronsted acidity is reported. The material has been synthesized via post-synthetic sulfonation of the porous co-polymer poly-divinylbenzene-co-triallylamine (PDVTA-1) using chlorosulfonic acid as sulfonating agent. A detailed characterization of the -SO3H functionalized porous polymeric material has been carried out using N2 sorption, FT-IR and UV-vis spectroscopy, HR-TEM, FE-SEM, thermogravimetric and elemental analyses. Temperature programmed desorption of NH3 (TPD-NH3 analysis) of PDVTA-SO3H revealed a very high surface acidity of 2.3 mmol g-1. Such high acidity of PDVTA-SO3H has been explored to investigate its catalytic efficiency towards eco-friendly production of biodiesel via esterification of long-chain free fatty acids (FFA) to the respective fatty acid monoalkyl esters (FAMEs) at room temperature using methanol as reactant as well as solvent. The sulfonated porous polymer is found to be a very active and reusable solid acid catalyst giving high yields (~92-98%) of various biodiesel compounds under very mild reaction conditions.
- Gomes, Ruth,Bhanja, Piyali,Bhaumik, Asim
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p. 110 - 116
(2015/11/11)
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- A magnetically recoverable nanocatalyst based on functionalized mesoporous silica
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A magnetically separable 2D-hexagonally ordered thiol functionalized mesoporous silica material (Fe@TFMS) has been synthesized through co-condensation reaction of 3-mercaptopropyltriethoxysilane (MPTES) and tetraethylorthosilicate (TEOS) using cetyltrimethylammonium bromide (CTAB) as a cationic surfactant followed by immobilization of Fe3O4 nanocrystallies at the functionalized mesopore surface. Powder X-ray diffraction (XRD), N2 adsorption/desorption analysis, FT-IR, TEM, FE-SEM, TGA/DTA, CHNS, XPS and NH3-TPD tools are employed to characterize the materials. This functionalized mesoporous material exhibited high catalytic activity in the biodiesel production from a wide range of long chain fatty acids and soybean oil. The material showed high Lewis acidity of 1.02 mmolg-1 with a good Brunauer-Emmett-Teller (BET) surface area of 411 m2 g-1. Fe@TFMS exhibited excellent catalytic efficiency for this esterification reaction using methanol as a solvent cum reactant under eco-friendly and mild reaction conditions (room temperature, 25 °C).
- Bhanja, Piyali,Sen, Tapas,Bhaumik, Asim
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- Sterols and Fatty Acids of the Harmful Dinoflagellate Cochlodinium polykrikoides
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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.
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p. 249 - 252
(2016/02/27)
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- Pyrazinium polyoxometalate tetrakaidecahedron-like crystals esterify oleic acid with equimolar methanol at room temperature
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Ionic-liquid-modified polyoxometalate was prepared by self-assembly of Keggin-type heteropolyacids and sulfonated pyrazinium-IL, in which no template, surfactant, or organic solvent was used. The obtained ionic hybrid exhibits uniform morphology of cubic tetrakaidecahedron-like crystals and possesses a larger number of strong acid sites with narrower dispersion of acid strength than its analogues with similar chemical composition but different morphology. Catalytic activity tests reveal its high conversion, stable recycling, and good substrate compatibility for esterification of free fatty acids (FFA) with methanol into biodiesel at room temperature and over a wide range of molar ratios of methanol to FFA (10-50). Even under the ideal stoichiometric conditions (methanol:FFA = 1:1, a viscous solution), it converts 83% of oleic acid in 24 h. Morphology and performance are discussed, suggesting that the uniform crystals translate into high activity due to improved accessibility of the strong acid sites on the smooth external surface of the catalyst.
- Li, Jing,Li, Difan,Xie, Jingyan,Liu, Yangqing,Guo, Zengjing,Wang, Qian,Lyu, Yinong,Zhou, Yu,Wang, Jun
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p. 123 - 134
(2016/05/09)
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- A new hypercrosslinked supermicroporous polymer, with scope for sulfonation, and its catalytic potential for the efficient synthesis of biodiesel at room temperature
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We have designed a new hypercrosslinked supermicroporous polymer (HMP-1) with a BET surface area of 913 m2 g-1 by FeCl3via a catalyzed Friedel-Crafts alkylation reaction between carbazole and α,α′-dibromo-p-xylene. Upon sulfonation HMP-1 yielded a very efficient solid acid catalyst for the production of biodiesels via esterification/transesterification of free fatty acids (FFA)/esters at room temperature.
- Bhunia, Subhajit,Banerjee, Biplab,Bhaumik, Asim
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supporting information
p. 5020 - 5023
(2015/03/30)
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- A novel aromatic carbocation-based coupling reagent for esterification and amidation reactions
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A novel tropylium-based coupling reagent has been developed to facilitate the synthesis of a series of esters, amides, lactones and peptides under mild reaction conditions. Remarkably, this reagent can be used in catalytic amounts in conjunction with a sacrificial reagent, offering a new and efficient method for nucleophilic coupling reactions of carboxylic acids.
- Nguyen, Thanh V.,Lyons, Demelza J.M.
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supporting information
p. 3131 - 3134
(2015/06/17)
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- Self-assembled sulfated zirconia nanocrystals with mesoscopic void space synthesized via ionic liquid as a porogen and its catalytic activity for the synthesis of biodiesels
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Abstract Self-assembled ZrO2 nanocrystals have been synthesized through a facile chemical route via steam-assisted ionothermal method using 1-butyl-3-methylimidazolium chloride ([bmim][Cl]) as a porogen. The template-free material has been sulphonated by 1(N) H2SO4 at room temperature followed by calcination in air at 723 K. Both ZrO2 and the sulfonated zirconia materials are thoroughly characterized by powder X-ray diffraction (PXRD), ultra high-resolution transmission electron microscopy (UHR-TEM), Fourier transform infrared spectroscopy (FT-IR), FE-SEM, N2 sorption, and NH3-TPD analyses. The sulfonated material has been employed as efficient and environmentally benign heterogeneous catalyst for the synthesis of biodiesels based on long chain fatty acid esters. The catalyst can be easily recovered and reused at least for five times without significant decrease in its catalytic activity.
- Banerjee, Biplab,Bhunia, Subhajit,Bhaumik, Asim
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p. 380 - 387
(2015/07/15)
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- Improved protocol toward 1,3,4-oxadiazole-2(3H)-thiones and scale-up synthesis in the presence of SDS as a micelle promoted catalyst
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Convenient procedure for in situ cyclization of hydrazinecarbodithioate potassium salts to 1,3,4-oxadiazole-2(3H)-thiones under normal phase micellar media catalysis promoted by sodium dodecyl sulfate (SDS) as an anionic surfactant is reported. The main advantage of this procedure is to provide shorter reaction time for the completion of cyclization; scale-up synthesis is possible and the oxadiazoles were obtained in high to excellent yields (87-100%), making the protocol an attractive alternative to the available methods.
- Yildirim, Ayhan
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p. 473 - 478
(2015/06/30)
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- GC-FID analysis of fatty acids and biological activity of Zanthoxylum rhetsa (Roxb.) DC seed oil
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The Fatty acid content and composition of fixed oil from Zanthoxylum rhetsa seeds was determined. The seeds were found to contain about ~19.5% of crude fixed oil on a dry weight basis. Fatty acids were converted into methyl esters and analyzed by GC-FID. Ten fatty acids were identified using GC-FID. The major monounsaturated and saturated fatty acids were oleic acid (41.6 - 43.5%) and palmitic acid (26.8-30.2%) respectively, whereas the α-linolenic acid (12.1 - 12.5%) and linoleic acid (10.0%) were polyunsaturated fatty acid. Stearic acid (5.2 - 6.0%), myristic acid (0.1%), traces of pentadecanoic, heptadecanoic and arachidic acid were also identified. These fatty acids have not been reported earlier from the oil of Z. rhetsa. Fixed oil exhibited significant free radical scavenging activity which was measured using DPPH, and is also known to inhibit the gastrointestinal motility significantly.
- Naik, Rajashri R.
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p. 1929 - 1935
(2016/02/27)
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- Efficient, stable, and reusable Lewis acid-surfactant-combined catalyst: One-pot Biginelli and solvent-free esterification reactions
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Cerium(III) trislaurylsulfonate (Ce(LS)3), a Lewis acid and surfactant combined catalyst, was prepared and characterized by SEM, SEM-EDX, XRD, NMR, FT-IR, TG, and elemental analysis. Ce(LS)3 was found to be stable and efficient to catalyze one-pot Biginelli and solvent-free esterification reactions. Furthermore, Ce(LS)3 is easy to recycle after reaction by pouring into cold water and filtration. Present work will shed deep insight into the understanding of the catalytic nature of LASCs, and extend its application in important organic transformations.
- Qiu, Yunfeng,Sun, Hongnan,Ma, Zhuo,Xia, Wujiong
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- Polystyrene-based superacidic solid acid catalyst: Synthesis and its application in biodiesel production
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A polystyrene-supported superacidic fluoroalkyl sulfonic acid catalyst (sPS-S) was synthesized using a combination of iridium-catalyzed C-H borylation and Suzuki-Miyaura coupling reactions. Catalytic activity of the new solid acid catalyst was examined for esterification of fatty acids and transesterification of triglyceride with methanol. Significantly higher activity than those of commercial sulfonated ion-exchange resins (Amberlyst 15 and Nafion NR50) was achieved with a catalyst loading as low as 0.5 wt%. The solid catalyst could be easily recovered by filtration and reused. Consistently high activities were obtained from the esterification for up to ten consecutive runs. This journal is
- Chang, Ying,Lee, Chohee,Bae, Chulsung
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p. 47448 - 47454
(2015/02/19)
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- Metal/bromide autoxidation of triglycerides for the preparation of FAMES to improve the cold-flow characteristics of biodiesel
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Triglyceride autoxidation using a homogeneous Co/Mn/Zr/bromide catalyst in acetic acid (93%) of low grade tallow, canola oil or soy bean oil in a batch reactor at 150 °C for 2 h, produced lower molecular weight products relative to the fatty acids of the starting triglycerides. For the autoxidation of tallow the main products after esterification were monoesters Me(CH 2)mC(O)OMe (m = 5-12) and diesters MeOC(O)(CH 2)nC(O)OMe, (n = 7-12). Oxidation of the saturated fatty acids in triglycerides was confirmed and modelled using methyl palmitate. Post-treatment esterification of tallow autoxidation products to produce biodiesel (BD) esters resulted in improved cold temperature properties by a mean of 13.0 °C, i.e. a mean cloud point (CP) 1.0 °C (cf. unmodified tallow biodiesel: CP 14 °C).
- Phung, Peter,Rowlands, William N.,Thiyakesan, Appadurai,Benndorf, Paul,Masters, Anthony F.,Maschmeyer, Thomas
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p. 162 - 168
(2014/07/07)
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- Methyl salicylate as a selective methylation agent for the esterification of carboxylic acids
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Methyl salicylate is a selective and inexpensive methylating agent for the esterification of carboxylic acids with a wide range of functional group tolerance. The intramolecular hydrogen bonds between the carboxylate and hydroxyl groups in methyl salicylate are essential for the transformation. Allyl, benzyl, methallyl, and propargyl salicylates can also be used as alkylating agents for the preparation of the corresponding alkyl carboxylates.
- Chen, Si,Jia, Lei,Li, Xiaonan,Luo, Meiming
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p. 263 - 268
(2014/03/21)
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- Stabilization of long-chain intermediates in solution. octyl radicals and cations
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The rearrangements of 1-octyl, 1-decyl and 1-tridecyl intermediates obtained from thermal lead(IV) acetate (LTA) decarboxylation of nonanoic, undecanoic and tetradecanoic acid were investigated experimentally through analysis and distribution of the products. The relationships between 1,5-, 1,6- and possibly existing 1,7-homolytic hydrogen transfer in 1-octyl-radical, as well as successive 1,2-hydride shift in corresponding cation have been computed via Monte-Carlo method. Taking into account that ratios of 1,5-/1,6-homolytic rearrangements in 1-octyl- and 1-tridecyl radical are approximately the same, the simulation shows very low involvement of 1,7-hydrogen rearrangement (1,5-/1,6-/1,7-hydrogen rearrangement = 85:31:1) in 1-octyl radical.
- Teodorovi?, Aleksandar V.,Badjuk, Dalibor M.,Stevanovi?, Nenad,Pavlovi?, Radoslav Z.
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- METHOD OF PRODUCING SATURATED ALKYL ESTERS/ACIDS
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Disclosed herein is the production of saturated alkyl esters or acids from furan materials. The starting compounds contain furan, ketone, and ester or acid functional groups and may be biologically-derived. The method includes hydrogenating the starting compound to form a reduced mixture. The method further includes hydrodeoxygenation of the reduced mixture to yield a saturated alkyl ester or acid. The saturated alkyl ester or acid can be unbranched or branched. The ester and acid products have a wide variety of applications and may be further processed into surfactants, solvents, and lubricants suitable for use in consumer products.
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-
Paragraph 0066; 0067
(2013/03/28)
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- Amino acid variability in the peptide composition of a suite of amphiphilic peptide siderophores from an open ocean Vibrio species
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In response to iron-depleted aerobic conditions, bacteria often secrete low molecular weight, high-affinity iron(III)-complexing ligands, siderophores, to solubilize and sequester iron(III). Many marine siderophores are amphiphilic and are produced in suites, wherein each member within a particular suite has the same iron(III)-binding polar head group which is appended by one or two fatty acids of differing length, degree of unsaturation, and degree of hydroxylation, establishing the suite composition. We report the isolation and structural characterization of a suite of siderophores from marine bacterial isolate Vibrio sp. Nt1. On the basis of structural analysis, this suite of siderophores, the moanachelins, is amphiphilic and composed of two N-acetyl-N-hydroxy-d- ornithines, one N-acetyl-N-hydroxy-l-ornithine, and either a glycine or an l-alanine, appended with various saturated and unsaturated fatty acid tails. The variation in the small side-chain amino acid is the first occurrence of variation in the peptidic head group structure of a set of siderophores produced by a single bacterium.
- Gauglitz, Julia M.,Butler, Alison
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p. 489 - 497
(2013/07/27)
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- Ultrasound-assisted synthesis of aliphatic acid esters at room temperature
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This work describes the ultrasound-assisted synthesis of saturated aliphatic esters from synthetic aliphatic acids and either methanol or ethanol. The products were isolated in good yields after short reaction times under mild conditions.
- Hobuss, Cristiane B.,Venzke, Dalila,Pacheco, Bruna S.,Souza, Alexander O.,Santos, Marco A.Z.,Moura, Sidnei,Quina, Frank H.,Fiametti, Karina G.,Vladimir Oliveira,Pereira, Claudio M.P.
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experimental part
p. 387 - 389
(2012/04/23)
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- Organic-inorganic hybrid porous sulfonated zinc phosphonate material: Efficient catalyst for biodiesel synthesis at room temperature
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A new porous zinc phosphonate material (HZnP-1) has been synthesized via the reaction between p-xylenediphosphonic acid and anhydrous ZnCl2 under hydrothermal and mildly acidic conditions (pH ~ 5) in the absence of any structure directing agent. The phenyl group of this material has been sulfonated with concentrated sulfuric acid to obtain sulfonic acid functionalized material HZnPS-1. Powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE SEM), N2 sorption, solid state 13C CP MAS and 31P MAS NMR, and FT IR spectroscopic tools are employed to characterize these materials. The crystal structures of both the materials are indexed corresponding to the new orthorhombic phases with unit cell parameters a = 11.00, b = 8.74, c = 14.62 A, α = β = γ = 90° for HZnP-1, and a = 10.65, b = 13.52, c = 15.30 A and α = β = γ = 90° for HZnPS-1. HZnPS-1 showed outstanding catalytic activity and high recycling efficiency for the synthesis of different biodiesel compounds via esterification of long chain fatty acids by using methanol as both reactant and solvent at room temperature. The green and eco-friendly catalytic system described herein can overcome the problem faced by the existing catalytic systems known in biodiesel synthesis, such as drastic conditions (high reaction temperature) and requirement of hazardous organic solvents.
- Pramanik, Malay,Nandi, Mahasweta,Uyama, Hiroshi,Bhaumik, Asim
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experimental part
p. 2273 - 2281
(2012/09/08)
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- Psammaplysin derivatives from the balinese marine sponge Aplysinella strongylata
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Twenty-one new psammaplysin derivatives (4-24) exhibiting a variety of side chains, as well as six previously known psammaplysins, were identified from the Indonesian marine sponge Aplysinella strongylata. The double bond on the side chain of the fatty acid-containing psammaplysins was located by GC-MS analysis of the fatty acid methyl esters and their pyrrolidide derivatives. HPLC and Mosher ester studies confirmed that the isolated metabolites possessing a 19-OH substituent were mixtures of diastereomers. Selected compounds (4, 5, 7, 8, 12, 18, and 22) were screened for in vitro activity against chloroquine-sensitive (3D7) P. falciparum malaria parasites. Of the new psammaplysins, 19-hydroxypsammaplysin E (4) showed the best antimalarial activity, with an IC50 value of 6.4 μM.
- Mudianta, I Wayan,Skinner-Adams, Tina,Andrews, Katherine T.,Davis, Rohan A.,Hadi, Tri A.,Hayes, Patricia Y.,Garson, Mary J.
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p. 2132 - 2143
(2013/02/25)
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- Isotope effects associated with the preparation and methylation of fatty acids by boron trifluoride in methanol for compound-specific stable hydrogen isotope analysis via gas chromatography/thermal conversion/isotope ratio mass spectrometry
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Rationale: Compound-specific stable hydrogen isotope analysis of fatty acids is being used increasingly as a means of deriving information from a diverse range of materials of archaeological, geological and environmental interest. Preparative steps required prior to isotope ratio mass spectrometry (IRMS) analysis have the potential to alter determined δD values and hence must be accounted for if accurate δD values for target compounds are to be obtained. METHODS Myristic, palmitic, stearic, arachidic and behenic saturated fatty acids were derivatised to their respective fatty acid methyl esters (FAMEs), using 14% (w/v) boron trifluoride in methanol then analysed by gas chromatography/thermal conversion/IRMS (GC/TC/IRMS). FAMEs generated from fatty acid sodium salts of unknown δD values were then used to test a correction factor determined for this method of derivatisation. RESULTS Derivatisation was found to alter the hydrogen isotopic composition of FAMEs although this effect was reproducible and can be accounted for. The difference between the mean corrected and mean bulk δD values was always less than 6.7 %. Extraction of saturated fatty acids and acyl lipids from samples, subsequent hydrolysis, then separation on a solid-phase extraction cartridge, was found to alter the determined δD values by less than one standard deviation. CONCLUSIONS Overall, it has been shown that for natural abundance hydrogen isotope determinations, the isolation and derivatisation of extracted fatty acids alters the determined δD values only by a numerical increment comparable with the experimental error. This supports the use of the described analytical protocol as an effective means of determining fatty acid δD values by GC/TC/IRMS. Copyright
- Chivall, David,Berstan, Robert,Bull, Ian D.,Evershed, Richard P.
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experimental part
p. 1232 - 1240
(2012/07/28)
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- Efficient conversion of triacylglycerols and fatty acids to biodiesel in a microwave reactor using metal triflate catalysts
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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.
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experimental part
p. 4753 - 4756
(2010/11/19)
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- DIRECT METHOD AND REAGENT KITS FOR FATTY ACID ESTER SYNTHESIS
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Provided are efficient, cost-effective and water tolerant methods (e.g., single-vial methods) for preparing fatty acid esters from organic matter, comprising: obtaining organic matter comprising at least one fat substituent, contacting the organic matter in a reaction mixture with a basic solution under conditions suitable to provide for hydrolytic release of monomeric fatty acids from the at least one fat substituent to provide a base-treated reaction mixture, and esterifying the monomeric fatty acids of the base-treated reaction mixture by acidification of the reaction mixture and treating in the presence of an organic alcohol to provide fatty acid esters. The methods optionally further comprise, prior to esterifying, neutralizing the base-treated reaction mixture to provide for neutralized fatty acids, separating the neutralized fatty acids from the neutralized reaction mixture, and dissolving the separated fatty acids in the esterification reaction mixture. Also provided are related methods and kits for fat analysis.
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Page/Page column 18; 21-22; 29
(2008/12/07)
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- SINGLE-STAGE ESTERIFICATION OF OILS AND FATS
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A process for producing alkyl esters useful as biofuels and/or lubricants. An alkyl ester product produced by the process. The process comprises a single- stage reaction for esterifying a de-watered glyceride-containing feedstock with an anhydrous short chain alcohol in the presence of a basic esterification catalyst to produce a reaction product comprising alkyl esters and a reaction by-product comprising glycerol-containing substances and the catalyst-containing alcohol. The single-stage esterification reaction is conducted within a temperature and negative-pressure controllable vessel. The alkyl ester product is separated from the reaction by-product and may be further de-watered and/or purified. The catalyst-containing alcohol may be separated from the reaction by-product, de- watered and reused. The glycerol-containing substances may be separated from the reaction by-product and further purified. Useful glyceride-containing feedstocks include those prepared from plant or animal or fish materials, particularly those produced from seeds of mustard, canola, soybean, corn, cotton, flax and palm.
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Page/Page column 10-12
(2008/06/13)
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- Process for separating saturated and unsaturated fatty acids for producing cold-tolorant biodiesel fuel from soy oil
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A process for separating a blend of saturated and unsaturated fatty acids or saturated and unsaturated fatty acid alkyl esters into a first fraction enriched with the saturated fatty acids or saturated fatty acid alkyl esters and a second fraction enriched with unsaturated fatty acids or unsaturated fatty acid alkyl esters. When separating fatty acids, the process includes the steps of (a) saponifying a blend of long chain saturated and unsaturated fatty acids to form free fatty acids, (b) complexing the free fatty acids with urea, and (c) separating the urea complexed free fatty acids into a first fraction enriched with saturated free fatty acids and a second fraction enriched with unsaturated free fatty acids. When separating fatty acid alkyl esters, the process includes the steps of (i) complexing the fatty acid alkyl esters with urea, and (ii) separating the urea complexed fatty acid alkyl esters into a first fraction enriched with saturated fatty acid alkyl esters and a second fraction enriched with unsaturated fatty acid alkyl esters.
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Page/Page column 3
(2008/06/13)
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- Constituents of Ocimum sanctum with antistress activity
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Three new compounds, ocimumosides A (1) and B (2) and ocimarin (3), were isolated from an extract of the leaves of holy basil (Ocimum sanctum), together with eight known substances, apigenin, apigenin-7-O-β-D-glucopyranoside, apigenin-7-O-β-D-glucuronic acid (4), apigenin-7-O-β-D-glucuronic acid 6″-methyl ester, luteolin-7-O-β-D-glucuronic acid 6″-methyl ester, luteolin-7-O-β-D-glucopyranoside, luteolin-5-O-β-D- glucopyranoside, and 4-allyl-1-O-β-D-glucopyronosyl-2-hydroxybenzene (5), and two known cerebrosides. The structures of the new compounds were determined on the basis of extensive 1D and 2D NMR spectroscopic analysis. The new compounds (1-3) and the known compounds 4 and 5 were screened at a dose of 40 mg/kg body weight for acute stress-induced biochemical changes in male Sprague-Dawley rats. Compound 1 displayed promising antistress effects by normalizing hyperglycemia, plasma corticosterone, plasma creatine kinase, and adrenal hypertrophy. Compounds 2 and 5 were also effective in normalizing most of these stress parameters. In contrast, compounds 3 and 4 were ineffective in normalizing any of these effects.
- Gupta, Prasoon,Yadav, Dinesh Kumar,Siripurapu, Kiran Babu,Palit, Guatam,Maurya, Rakesh
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p. 1410 - 1416
(2008/04/01)
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- Design, synthesis, antibacterial, and QSAR studies of myristic acid derivatives
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A series of esters and amides of myristic acid was synthesized and tested in vitro for antibacterial activity against Gram-positive and Gram-negative bacteria. All the compounds showed activity comparable to that of the standard drug, ciprofloxacin. The structural characteristics governing antibacterial activity of myristic acid derivatives was studied using QSAR methodology. The results showed that the antibacterial activity could be modeled using the topological descriptor, valence molecular connectivity index. The predictive ability of the models was cross-validated by construction of a test set. The low residual activity and high cross-validated r2 values ( rcv2 ) observed indicated the predictive ability of the developed QSAR models.
- Narasimhan, Balasubramanian,Mourya, Vishnukant,Dhake, Avinash
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p. 3023 - 3029
(2008/09/20)
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