A new diterpene dimer from the bark ofChamaecyparis obtusa

This paper describes characterization of diterpenes of the bark of Japanese cypress,Chamaecyparis obtusa (S. and Z.) Endl, without the resinous stem canker to learn the difference between the cypress bark affected with the canker. A diterpene dimer and two diterpenes, 6,12-dihydroxyabieta-8,11,13-trien-7-one and 6,12-dihydroxyabieta-5,8,11, 13-tetraen-7-one, were firstly isolated from Japanese cypress. The dimer, 6-(abieta-6,8,11, 13-tetraenyl-12-oxy)-7-methoxyabieta-8,11,13-trien-12-ol, was a new compound. It is a terpene indicative ofC. obtusa not infected with the resinous stem canker. Five known diterpenes were also isolated.