Microbial transformation of diosgenin by filamentous fungus Cunninghamella echinulata

Abstract

Microbial transformation of diosgenin (1) by suspended-cell cultures of the filamentous fungus Cunninghamella echinulata CGMCC 3.2000 was investigated. Incubation of the substrate diosgenin (1) with this fungus led to the isolation of three products: two known compounds, (25R)-spirost-5-en-3β,7β,12β-triol (2) and (25R)-spirost-5-en-3β,7β,11α-triol (3), and a new compound (25R)-spirost-5-en-3β,7α,11α-triol (4). The structural elucidations of the three compounds were achieved mainly by the MS, 1D and 2D NMR spectroscopic methods and comparison with known compounds. C. echinulata CGMCC 3.2000 has not been used before in the biotransformation of diosgenin (1).

Keywords:

• microbial transformation
• biotransformation
• hydroxylation
• diosgenin Cunninghamella echinulata CGMCC 3.2000

Acknowledgements

This work is financially supported by the New Drug Development Project of China (Project No. 2009ZX09301-003).