Biotransformation of 2α,5α,10β,14β-tetra-acetoxy-4(20), 11-taxadiene by Ginkgo cell suspension cultures

Ginkgo biloba cell suspension cultures were used to biotransform 2 alpha ,5 alpha ,10 beta ,14 beta -tetra-acetoxy-4(20),11-taxadiene. Two novel compounds were obtained and their structures were identified as 9 alpha -hydroxyl-2 alpha ,5 alpha ,10 beta ,14 beta -tetra-acetoxy-4(20), 11-taxadiene 1 and 9 alpha, 10 beta -dihydroxyl-2 alpha ,5 alpha ,14 beta -tri-acetoxy-4(20), 11-taxadiene 2, respectively, on the basis of their physical and chemical data. Compound 1 was subsequently used as a substrate for the bioconversion by Ginkgo cell cultures, and the product obtained was confirmed to be the same as 2, which suggested that 2 is biosynthesized From 1. investigation on properties of the related enzymes responsible for the biotransformation reaction through the experimental techniques of cell-free culture and substrate/product concentration analysis revealed that the enzymes were extracellular and constitutive. (C) 2001 Elsevier Science Ltd. All rights reserved.