C11 α-hydroxylation of C21 Steroidal Aglycones in Cynanchum Auriculatum by Microbial Simultaneously Transformation

OBJECTIVE Two species of C21 steroidal aglycones of Caudatin steroidal aglycones and Kaider steroidal aglycones, which were extracted from Cynanchum auriculatum, could be C11 α-hydroxylated with low by-product content and high-yield objectives. METHODS Rhizopus nigricans and Absidia sp. Were used to synchronized transformation and by shaking cultivation for 70 hours at 30 ℃ in water/butanol two-phase system with pH=5.0-6.0. RESULTS The products were confirmed to be C11 α-hydroxylated Caudatin steroidal aglycones and Kaider steroidal aglycones by IR, MS, and NMR. The results also indicated that by-product content was low and the yield of objectives was up to 70.1%. CONCLUSIONS The method was high effective for C11 α-hydroxylation of C21 steroidal aglycones in water/butanol two-phase system by Rhizopus nigricans and Absidia sp