The antimalarial drug arteether [1] was subjected to microbial metabol
ism using Cunninghamella elegans (ATCC 9245) and Streptomyces lavendul
ae (L-105). 1 alpha-Hydroxyarteether [2], a novel microbial metabolite
of 1 was isolated from the cultures of C, elegans and fully character
ized. The stereochemistry of 2 was established by X-ray crystallograph
ic analysis. 9 beta-Hydroxyarteether [3] was isolated from the same cu
lture in a much higher yield (40%) than previously reported (2.2%). Co
mpound 6, a known metabolite of 1, was isolated from the fermentation
cultures of S, lavendulae for the first time.