An ent-kaurane diterpenoid from Isodon japonica var. glaucocalyx.

ABSTRACT: The title compound, 14?-acet-oxy-7?-hydr-oxy-ent-kaur-16-ene-3,15-dione or glaucocalyxin B, C(22)H(30)O(5), a natural ent-kaurane diterpenoid, is composed of four rings with the expected cis and trans ring junctions. In the crystal structure, there are two mol-ecules in the asymmetric unit related by a noncrystallographic twofold screw axis, and ring A is disordered [ratio occupancies 0.829?(19):0.171?(19)], such that both chair and boat conformations are present, but with the boat conformation as the major component. In the crystal, mol-ecules are linked by inter-molecular O-H?O hydrogen bonds.

SUBMITTER: Bai SP 

PROVIDER: S-EPMC2977125 | biostudies-other | 2009 Jul

REPOSITORIES: biostudies-other