Two new antifungal diterpenes, metasequoic acid A(4) and B(5) were isolated from Metasequoia glyptostroboides Hu et Cheng. These compounds possess a new skeleton which contains a cyclopropane ring bridging C-3 and C-4 of the labdane framework. The structures 4 and 5 have been determined by spectroscopic methods.

中文翻译：

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水杉酸A和B的结构

从水杉 glyptostroboides Hu et Cheng 中分离出两种新的抗真菌二萜、水杉酸 A(4) 和 B(5)。这些化合物拥有一个新的骨架，其中包含一个环丙烷环，桥接劳丹烷骨架的 C-3 和 C-4。结构4和5已通过光谱方法确定。