Two New Cleistanthane Diterpenes and a New Isocoumarine from Cultures of the Basidiomycete Albatrellus confluens

Two new cleistanthane-type diterpenes, 3 alpha,5 alpha,8 beta-trihydroxycleistanth-13(17),15-dien-18-oic acid (1) and 8 beta-hydroxy-18-norcleistanth-4(5),13(17),15-trien-3-one (2), a new isocoumarine, 3R-(2R-hydroxypropyl)-8-hydroxyl-7-methyl-3,4-dihydroisocoumarine (3), along with three known aurovertins, aurovertins B (4), C (5) and E (6), four known polyesters, orbuticin (7), BK223A (8), BK223B (9) and 15G256 alpha-2-me (10), and a known isocoumarine, 3R-6-hydroxymellein (11), were isolated from cultures of the basidiomycete Albatrellus confluens. The structures of these compounds were established on the basis of spectroscopic and chemical methods.