THE BIOTRANSFORMATION OF TWO ENT-15β,16β-EPOXY-KAURANE DERIVATIVES BY GIBBERELLA FUJIKUROI

Article abstract of DOI:10.1016/S0031-9422(00)90794-5

The microbiological transformation of the diterpene ent-15β,16β-epoxy-14α-hydroxykaurane into ent-14α,15β-dihydroxy-11α,16α-epoxykaurane, ent-7α,14α,15β-trihydroxy-11α,16α-epoxykaurane and ent-7β,14α,15β-trihydroxy-11α,16α-epoxykaurane has been carried out using the fungus Gibberella fujikuroi.The incubation with this fungus of sideroxol (ent-7α,18-dihydroxy-15β,16β-epoxykaurane) gave as main products ent-7α,15β,18-trihydroxy-11α,16α-epoxykaurane and ent-7α,13,18-trihydroxy-15α,16α-epoxykaurane.Some of these compounds were identified as their acetate derivatives.The presence of the 15α,16α-epoxy group in these two substrates inhibits transformations involving oxidation at C-9 and favours the hydroxylation at C-11(β).