A new diterpenoid, carneadiol, isolated from Nocardia carnea IFM 12324.

A new diterpenoid, carneadiol (1), with an unprecedented tricyclic carbon skeleton, was isolated from the culture extracts of Nocardia carnea IFM 12324. The structure of compound 1 was elucidated using spectral studies, including various NMR data. The absolute configuration of 1 was determined using X-ray crystallographic analysis with the crystalline sponge method. The biosynthetic gene of compound 1 was deduced, and it was observed that the mRNA of the gene involved in terpenoid cyclization increased significantly in the strain producing compound 1.