Rearrangement and oxidation of β-amyrin promoted by growing cells of Lecanicillium muscarinium
摘要:
Microbial transformation of -amyrin by growing cells of the fungus Lecanicillium muscarinium (former Cephalosporium aphidicola) was successfully accomplished after 15 days of incubation with orbital shaking at 120 rpm. Two products purified by column chromatography were identified by 1H and 13C mono- and bi-dimensional nuclear magnetic resonance as 3-hydroxy-olean-12-en-11-one and 11,12-oxidotaraxerol; these later formed new compounds formed by an interesting oxidative rearrangement of the starting material, probably via an initial hydroxylation at C-11.
Microbial transformation of -amyrin by growing cells of the fungus Lecanicillium muscarinium (former Cephalosporium aphidicola) was successfully accomplished after 15 days of incubation with orbital shaking at 120 rpm. Two products purified by column chromatography were identified by 1H and 13C mono- and bi-dimensional nuclear magnetic resonance as 3-hydroxy-olean-12-en-11-one and 11,12-oxidotaraxerol; these later formed new compounds formed by an interesting oxidative rearrangement of the starting material, probably via an initial hydroxylation at C-11.
Studies on oxidation of triterpenoids: part vii. Transformation of oleanane and ursane skeletons to 11α, 12α-oxidotriterpenoids with hydrogen perox
Hydrogen peroxide-selenium dioxide in -butanol has been found to be a good reagent for the preparation of 11α,12α, -oxidotriterpenoids of oleanane and ursane skeletons; whereas α -amyrin and β-amyrin acetates furnished 11α,12α -epoxyurs-14-en-3β-yl acetate () and 11α, 12α -epoxytaraxer-14-en-3β-yl acetate () respectively, uvaol and ursolic acid/methyl ester gave 11α, 12α -epoxyurs-28→13-olide-3β-ol