In the present study, free fatty acids(FFAs, including palmitic acid, stearic acid, oleic acid, linoleic acid and arachidonic acid) in rabbit plasma were determined by gas chromatography-mass spectrometry(GC-MS) after...In the present study, free fatty acids(FFAs, including palmitic acid, stearic acid, oleic acid, linoleic acid and arachidonic acid) in rabbit plasma were determined by gas chromatography-mass spectrometry(GC-MS) after trimethylsilylation derivatization using N,O-bis(trimethylsilyl)trifluoroacetamide(BSTFA) – trimethylchlorosilane(TMCS) as derivatization reagent. The experimental conditions, including extraction and silylation reaction, were investigated. The method was experimentally validated. The linearity between fatty acids’ peak areas and their concentrations was obtained with the corelative coefficient(r2) all more than 0.999, and the recoveries were between 82% and 111%. The intra-day variations of FFAs’ in plasma samples at different concentrations were all less than 6%. FFA analysis results of 16 rabbit plasma samples showed that the method could be well applied in the determination of plasma samples in vivo. In contrast to the traditional method of FFA derivatization, the established trimethylsilylation method presented simplicity, high specificity, and completely free from the interference of the esterified fatty acid, such as triacylglyceride. The method could be applied for analyzing FFA profiles in the clinical laboratory or pharmacological research.展开更多
Two protected single amino acid chelates,N~α-Fmoc-N~ε,N~ε-di((2,2-dimethyl-1,3-dithian-5-yl)methyl)-L-lysine(7) and N~α-Fmoc-N~ε-(2,2-dimethyl-1,3-dithian-5-yl)methyl,N~ε-Boc-L-lysine(9),were synthesized by modi...Two protected single amino acid chelates,N~α-Fmoc-N~ε,N~ε-di((2,2-dimethyl-1,3-dithian-5-yl)methyl)-L-lysine(7) and N~α-Fmoc-N~ε-(2,2-dimethyl-1,3-dithian-5-yl)methyl,N~ε-Boc-L-lysine(9),were synthesized by modifying the side chain of lysine with 1,3-dithiane through direct reductive N-alkylation protocol.These amino acids have potential uses in peptide chemistry.展开更多
A copper-catalyzed highly stereoselective cyclopropanation of 1,2-disubstituted olefins with α-nitrodiazo acetates has been developed, giving the desired products in up to 97 % yields, up to 〉99/1 dr and up to 98 % ...A copper-catalyzed highly stereoselective cyclopropanation of 1,2-disubstituted olefins with α-nitrodiazo acetates has been developed, giving the desired products in up to 97 % yields, up to 〉99/1 dr and up to 98 % ee, which provides an efficient access to the synthesis of optical active cyclopropane α-amino acids and unnatural α-amino acid derivatives.展开更多
基金National Natural Science Foundation of China (Grant No. 31671928)Natural Science Foundation of Shanghai (Grant No. 15ZR1440800)。
文摘In the present study, free fatty acids(FFAs, including palmitic acid, stearic acid, oleic acid, linoleic acid and arachidonic acid) in rabbit plasma were determined by gas chromatography-mass spectrometry(GC-MS) after trimethylsilylation derivatization using N,O-bis(trimethylsilyl)trifluoroacetamide(BSTFA) – trimethylchlorosilane(TMCS) as derivatization reagent. The experimental conditions, including extraction and silylation reaction, were investigated. The method was experimentally validated. The linearity between fatty acids’ peak areas and their concentrations was obtained with the corelative coefficient(r2) all more than 0.999, and the recoveries were between 82% and 111%. The intra-day variations of FFAs’ in plasma samples at different concentrations were all less than 6%. FFA analysis results of 16 rabbit plasma samples showed that the method could be well applied in the determination of plasma samples in vivo. In contrast to the traditional method of FFA derivatization, the established trimethylsilylation method presented simplicity, high specificity, and completely free from the interference of the esterified fatty acid, such as triacylglyceride. The method could be applied for analyzing FFA profiles in the clinical laboratory or pharmacological research.
文摘Two protected single amino acid chelates,N~α-Fmoc-N~ε,N~ε-di((2,2-dimethyl-1,3-dithian-5-yl)methyl)-L-lysine(7) and N~α-Fmoc-N~ε-(2,2-dimethyl-1,3-dithian-5-yl)methyl,N~ε-Boc-L-lysine(9),were synthesized by modifying the side chain of lysine with 1,3-dithiane through direct reductive N-alkylation protocol.These amino acids have potential uses in peptide chemistry.
基金supported by the National Natural Science Foundation of China(21421091,21432011 and21272250)the Chinese Academy of Sciences
文摘A copper-catalyzed highly stereoselective cyclopropanation of 1,2-disubstituted olefins with α-nitrodiazo acetates has been developed, giving the desired products in up to 97 % yields, up to 〉99/1 dr and up to 98 % ee, which provides an efficient access to the synthesis of optical active cyclopropane α-amino acids and unnatural α-amino acid derivatives.
