The enantioselective total synthesis of 12 carboxyeudesma 3,11(13) diene(1) was achieved starting from(-) dihydrocarvone in ten steps for the first time. The key steps mainly include the introduction of hydroxyl group...The enantioselective total synthesis of 12 carboxyeudesma 3,11(13) diene(1) was achieved starting from(-) dihydrocarvone in ten steps for the first time. The key steps mainly include the introduction of hydroxyl group into C 12 position of eudesmane by Vilsmeier chlorination and the generation of C3-C4 double bond into the eudesmane skeleton by elimination of halide.展开更多
A full-length sequence coding for △^12 fatty acid desaturase gene from peanut（Arachis hypogaea L.）was cloned into the expression vector, pRSETB, to generate recombinant plasmid pRSET/HO-A, which was subsequently tr...A full-length sequence coding for △^12 fatty acid desaturase gene from peanut（Arachis hypogaea L.）was cloned into the expression vector, pRSETB, to generate recombinant plasmid pRSET/HO-A, which was subsequently transformed into expression Escherichia. coli BL21（DE3）pLysS. The △^12 fatty acid desaturase was highly expressed in E. coli BL21（DE3）pLysS in the presence of isopropyl-D-thiogalactopyranoside （IPTG）. The fusion protein was purified and used to form a reaction system in vitro by adding oleic acid as substrate and incubating it at 20℃ for 6 h. Total fatty acids was extracted and methlesterified and then analyzed with gas chromatography. A novel peak corresponding to linoleic acid methyl ester standards was detected with the same retention time. GC-MS （gas chromatogram and gas chromatogram-mass spectrometry） analysis showed that the novel peak was linoleic acid methyl ester. These results exhibited △^12 fatty acid desaturase activity, which could convert oleic acid to linoleic acid specifically.展开更多
文摘The enantioselective total synthesis of 12 carboxyeudesma 3,11(13) diene(1) was achieved starting from(-) dihydrocarvone in ten steps for the first time. The key steps mainly include the introduction of hydroxyl group into C 12 position of eudesmane by Vilsmeier chlorination and the generation of C3-C4 double bond into the eudesmane skeleton by elimination of halide.
基金This work was supported by Chinese National Programs for High Technology Research and Development (No. 2002AA207004).
文摘A full-length sequence coding for △^12 fatty acid desaturase gene from peanut（Arachis hypogaea L.）was cloned into the expression vector, pRSETB, to generate recombinant plasmid pRSET/HO-A, which was subsequently transformed into expression Escherichia. coli BL21（DE3）pLysS. The △^12 fatty acid desaturase was highly expressed in E. coli BL21（DE3）pLysS in the presence of isopropyl-D-thiogalactopyranoside （IPTG）. The fusion protein was purified and used to form a reaction system in vitro by adding oleic acid as substrate and incubating it at 20℃ for 6 h. Total fatty acids was extracted and methlesterified and then analyzed with gas chromatography. A novel peak corresponding to linoleic acid methyl ester standards was detected with the same retention time. GC-MS （gas chromatogram and gas chromatogram-mass spectrometry） analysis showed that the novel peak was linoleic acid methyl ester. These results exhibited △^12 fatty acid desaturase activity, which could convert oleic acid to linoleic acid specifically.
