The molecular structure of Ia, which was deduced from the result of crystal structure analysis of Ib, shows that it is a novel diterpene containing chlorine with a 5,11-bicyclic carbon skeleton, the molecular formula C20H33O4Cl.

• 由Ib的晶体结构分析结果推断Ia的分子式为C_(20)H-(33)O_4Cl。 它是一个具有五、十一员双环碳骨架的新型含氯二萜。