Lithocarpic Acids A鈥揘, 3,4-seco-Cycloartane Derivatives from the Cupules of Lithocarpus polystachyus

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• 作者：Hongmin Wang ; Ruonan Ning ; Yu Shen ; Zhenhua Chen ; Jinlong Li ; Rujun Zhang ; Ying Leng ; Weimin Zhao
• 刊名：Journal of Natural Products
• 出版年：2014
• 出版时间：August 22, 2014
• 年：2014
• 卷：77
• 期：8
• 页码：1910-1920
• 全文大小：472K
• ISSN：1520-6025

文摘

Fourteen new 3,4-seco-cycloartane-type triterpenes, lithocarpic acids A鈥揘 (1鈥?b>14), together with one known compound, coccinetane E (15), were identified from the cupules of Lithocarpus polystachyus. The structures of 1鈥?b>14 were determined by spectroscopic data analysis and chemical methods, and the absolute configurations of 1 and 4 were defined unequivocally by X-ray crystallography using Cu K伪 radiation. Compounds 1鈥?b>15 are the first examples of 3,4-seco-cycloartane derivatives isolated from the genus Lithocarpus. Among them, compounds 1 and 2, 9 and 10, and 11 and 12 were found to be three pairs of C-24 epimers, while compounds 7 and 8 represent the first examples of 3,4-seco-norcycloartane-type triterpenes. Compound 1, as the major component of the plant extract, showed potent antibacterial activity against Micrococcus luteus and Bacillus subtilis, with MIC values of 3.1 and 6.3 渭g/mL, respectively, as well as inhibitory activity against human and mouse 11尾-hydroxysteroid dehydrogenase type 1, with IC₅₀ values of 1.9 and 0.24 渭M, respectively.