CHEMICAL COMPOUNDS FROM THE BARK OF Cratoxylum formosum ssp. pruniflorum

摘要

Cratoxylum formosum ssp. pruniflorum is a valuable species distributed in Yunnan and Guangxi Provinces of China. Thirteen compounds have been isolated from the bark of C. formosum ssp. pruniflorum. Their structures were identified on the basis of spectroscopic analysis and chemical evidence: epifriedelinol (2), vismiaquinone B (3), 3,8-dihydroxy-1,2,4- trimethoxyxanthone (5), methyl-2,6-dihydroxy-3,4-dimethylbenzoate (6), 1,7-dihydroxy-4-methoxyxanthone (7), 11-hydroxy- 5-methoxy-2,2,9-trimethyl-2H-naphtho[1,2-b]pyran-7,12-dione (8), physcion (9), 1,8-dihydroxy-2-methoxyxanthone (10), vismione B (11), neriifolone C (12), and 1,7-dihydroxyxanthone (13). Compounds 1 and 4 were identified by direct comparison with authentic samples as β-sitosterol and friedelin, respectively. Among them, compounds 1, 2-6, 10, 11, and 13 were isolated from C. formosum ssp. pruniflorum for the first time.