Structures of Metasequoic Acid A and B

Abstract

Abstract Two new antifungal diterpenes, metasequoic acid A(4) and B(5) were isolated from Metasequoia glyptostroboides Hu et Cheng. These compounds possess a new skeleton which contains a cyclopropane ring bridging C-3 and C-4 of the labdane framework. The structures 4 and 5 have been determined by spectroscopic methods.