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《Biocatalysis and Biotransformation》2013,31(5):212-216
AbstractThe stereoselective oxidation of (—)-isolongifolanol (1) with a longifolene skeleton by Aspergillus niger (NBRC 4414) as a biocatalyst and suppressive effect on umuC gene expression by chemical mutagens furylfuramid and AFB1 of the SOS response in Salmonella typhimurium TA1535/pSK1002 were investigated. Compound 1 was converted to a new terpenoid, (-)-(2S,8R)-8,12-dihydroxy-isolongifolanol (2). Its structure was determined by NMR, IR, specific rotation and mass spectrometry. The metabolites suppressed the SOS-inducing activity of furylfuramid and AFB1 in the umu test. Compound 1 suppressed 51% of the SOS-inducing activity against furylfuramid at < 1.0 mM. Compound 2 suppressed 15% and 24% of the SOS-inducing activity against furylfuramid and AFB1 at < 1.0 mM respectively. 相似文献
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《Bioscience, biotechnology, and biochemistry》2013,77(7):1362-1366
A facile synthesis method is described for transforming the reducing-end residue of chitooligosaccharides (DP 2–4) into lactone. The desired 4-O-β-N-acetylchitooligosyl lactones (GNnL) were conveniently prepared from chitooligosaccharides by consecutive dehydration and oxidation reactions to afford 4-O-β-tri-N-acetylchitotriosyl 2-acetamido-2,3-dideoxydidehydro-gluconolactone (GN3L), 4-O-β-di-N-acetylchitobiosyl 2-acetamido-2,3-dideoxydidehydro-gluconolactone (GN2L), and 4-O-β-2-acetamido-2-deoxy-D-glucopyranosyl 2-acetamido-2,3-dideoxydidehydro-gluconolactone (GNL). The resulting lactone derivatives exhibited considerable suppression (42.6–54.3% at a concentration of 400 µM) in umu gene expression of the SOS response in Salmonella typhimurium TA1535/pSK1002 against the mutagen, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamido (AF-2). Lactonization of the chitooligosaccharides was found to be essential for their suppression of the SOS-inducing activity. 相似文献
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Takao Yokota David R. Reeve Alan Crozier 《Bioscience, biotechnology, and biochemistry》2013,77(10):2091-2094
The synthesis of 2,3-(3H)-gibberellin A9 (GA9) with a specific activity of 47 Ci mmole?1 is described. △2,3GA9 methyl ester epoxide was converted to (3H)-GA9 methyl ester epoxide using carrier-free tritium gas. This product was de-epoxidized then hydrolysed to yield (3H)-GA9. 相似文献
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Shigeki Yamada Chikara Hongo Masao Yamamoto Ichiro Chibata 《Bioscience, biotechnology, and biochemistry》2013,77(7):1425-1427
To develop a practical method for production of l-α-methyl DOPA, the optical resolution of its precursor, dl-3-(3,4-methylenedioxyphenyl)-2-methylalanine, was studied. The monohydrochloride of dl-3-(3,4-methylenedioxyphenyl)-2-methylalanine was resolved by a preferential crystallization procedure. Optically pure l-α-methyl DOPA was obtained in good yield. Industrial production of l-α-methyl DOPA by the present simple method is considered to be very promising. 相似文献
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