Seven undescribed isopimarane diterpene glycosides hypoxylonoids A-G, along with five known analogues were obtained from the fungus Xylaria hypoxylon. The structures and absolute configurations of hypoxylonoids A-G were confirmed by extensive spectroscopic and single-crystal X-ray diffraction analyses. Among these compounds, the γ-lactone moiety formed between C-19 and C-6 of hypoxylonoid A; the 1,2-methyl shift of Me-18 of hypoxylonoids B and E; and the decarboxylation of C-19 of hypoxylonoid E, make them outstanding from the isopimarane family. Single crystal X-ray diffraction analyses of hypoxylonoids A, C, F, and 15-hydroxy-16-α-D-mannopyranosyloxyisopimar-7-en-19-oic acid was performed to determine their absolute structural configuration.

中文翻译：

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Hypoxylonoids A-G：来自 Xylaria hypoxylon 的异海松二萜糖苷

从真菌 Xylaria hypoxylon 中获得了七种未描述的异海松烷二萜糖苷类物质 AG，以及五种已知的类似物。通过广泛的光谱和单晶 X 射线衍射分析证实了次木质素 AG 的结构和绝对构型。在这些化合物中，γ-内酯部分形成于次木酸 A 的 C-19 和 C-6 之间；次木酮 B 和 E 的 Me-18 的 1,2-甲基转移；以及次木酮 E 的 C-19 的脱羧，使它们在异海松烷家族中脱颖而出。对次木质素 A、C、F 和 15-羟基-16-α-D-mannopyranosyloxyisopimar-7-en-19-oic 酸进行单晶 X 射线衍射分析，以确定它们的绝对结构构型。