Two new cycloartane-type triterpenoids and one new flavanone from the leaves of Dasymaschalon dasymaschalum and their biological activity

Two new cycloartane-type triterpenoids, 3 beta-hydroxy-21-O-acetyl-24-methylenecycloartane (3) and 3 beta,21-dihydroxy-24,31-epoxy-24-methylenecycloartane (4), one new flavanone, 7-hydroxy-6,8-dimethoxyflavanone (5), two new natural products, 2-hydroxybenzyl benzoate (7) and 2-phenyl-2-acetoxyethyl benzoate (8), and ten known compounds, 3 beta-hydroxy-24-methylenecycloartane (1), 3 beta,21-dihydroxy-24-methylenecycloartane (2), desmosdumotin B (6), artabotrene (9), (-)-senepoxide (10), (+)-crotepoxide (11), (-)-1,6-desoxypipoxide (12), rotundol (13), cassipourol (14) and (+)-spathulenol (15) were isolated from the leaves of Dasymaschalon dasymaschalum. The structures of the new compounds were elucidated by spectroscopic analysis and of the known compounds by comparison of their physical, UV, IR, H-1 and C-13 NMR data with those of published compounds. Antimycobacterial, antiplasmodial and cytotoxic activities of the isolates, except 8 and 10 were evaluated. Compounds 1, 4, 5, 11, 12 and 15 exhibited potent cytotoxic activities against human lung cancer cell lines (NCI-H187) with respective IC50 values of 4.67, 7.82, 1.85, 6.33, 3.07 and 6.68 mg/mL. (C) 2013 Phytochemical Society of Europe. Published by Elsevier B. V. All rights reserved.