KM-01, a brassinolide inhibitor, its production, isolation and structure from two fungi Drechslera avenae and Pycnoporus coccineus.

A new brassinolide inhibitor, named KM-01, was isolated from the culture filtrates of two fungal species, Drechslera avenae and Pycnoporus coccineus, and the structure with absolute stereochemistry was elucidated as the fatty acid ester of an eremophilane sesquiterpene, bipolaroxin, based on spectroscopic analysis, chemical degradation, and synthesis of the fatty acid.