Antibiotics from basidiomycetes. XXXVII. New inhibitors of cholesterol biosynthesis from cultures of Xerula melanotricha Dörfelt.

Three new inhibitors of cholesterol biosynthesis have been isolated from cultures of Xerula melanotricha and their structures elucidated by spectroscopic methods. Dihydroxerulin (1) in admixture with xerulin (2) strongly inhibits the incorporation of 14C- acetate into cholesterol in HeLa cells while the incorporation of 14C-mevalonate is not affected. Xerulinic acid (3) shows similar biological activities but a higher cytotoxicity.