18-nor-Podocarpanes and podocarpanes from the Bark of Taiwania cryptomerioides.

Seven nor- and podocarpane-type diterpenes were isolated from the bark of Taiwania cryptomerioides Hayata, including three 18-nor-podocarpanes: 18-nor-1beta,4alpha,14-trihydroxy-13-methoxy-8,11,13-podocarpatriene (1), 18-nor-1beta,4alpha,13,14-tetrahydroxy-8,11,13-podocarpatrien-7-one (2), 18-nor-1beta,4alpha,14-trihydroxy-13-methoxy-8,11,13-podocarpatrien-7-one (3), 1beta,14,19-trihydroxy-13-methoxy-8,11,13-podocarpatrien-7-one (4), 1beta,13,14,18-tetrahydroxy-8,11,13-podocarpatrien-7-one (5), 18-acetoxy-1beta,13,14-trihydroxy-8,11,13-podocarpatrien-7-one (6), and 1beta,14,18-trihydroxy-13-methoxy-8,11,13-podocarpatrien-7-one (7). Their structures were determined by application of 1D and 2D NMR spectroscopy and other techniques. Podocarpane-type diterpenes do not occur extensively in nature, and the presumed oxidative enzyme in this plant will be of interest to identify.