Labdane diterpenes from the seeds of Platycladus orientalis.

Two new labdane diterpenes, 14(R),15-dihydroxy-8(17),12(E)-labdadien-19-oic acid (1) and 16-methyl-12,15-epoxy-8(17),13-labdadien-19-oic acid (2), together with four known compounds, were isolated from the seeds of Platycladus orientalis. Their structures were established by spectroscopic methods. The stereochemistry of compound 1 was defined by X-ray crystallographic analysis.