Biflavones from Chamaecyparis obtusa.

From the leaves of Chamaecyparis obtusa several biflavones were isolated and identified, namely: sciadopitysin, ginkgetin, isoginkgetin, podocarpusflavone B, 7,7"-O-dimethylamentoflavone, bilobetin, podocarpusflavone A, and 7-O-methylamentoflavone. The presence of amentoflavone and hinokiflavone was also confirmed. The composition of biflavones in other Chamaecyparis species--Ch. lawsoniana, Ch. thyoides--and cultivar varieties--Ch. pisifera "Squarrosa", Ch. pisifera "Boulevard"--was compared using the HPLC method. It was stated, that podocarpusflavone A and 7-O-methylamentoflavone in addition to amentoflavone and hinokiflavone may be classified as chemotaxonomic markers of the genus Chamaecyparis.