| Abstract: | A dihydrobenzo[c]phenanthridine alkaloid, epi-zanthocadinanine A (1), together with 27 known compounds, including eight benzo[c]phenanthridines: oxyavicine (2), oxynitidine (3), oxychelerythrine (4), dihydrochelerythrine (5), 6-acetonyldihydrochelerythrine (6), norchelerythrine (7), decarine (8), and arnottianamide (9); two 2-quinolones: flindersine (10), and 4-methoxy-1-methyl-2-quinolone (11); two furoquinolines: skimmianine (12), andγ-fagarine (13); three aporphines: liriodenine (14), N-acetyldehydroanonaine (15), and N-acetylanonaine (16); six lignans: sesamin (17), epi-sesamin (18), piperitol-3,3-dimethylallyl ether (19), xanthoxylol-3,3-dimethylallyl ether (20), savinin (21), and 2,3-di(3,4-methylenedioxybenzyl)-2-buten-4-olide (22); three terpenoids: α-cadinol (23), anticopalol (24), and spathulenol (25); one coumarin: aesculetin dimethyl ether (26); and two steroids: β-sitosterol (27), and β-sitostenone (28) were isolated from the stem bark of Zanthoxylum nitidum. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR as well as MS analyses. Moreover, rhoifoline A (2'), B (3'), and 8-methoxynorchelerythrine (4') were reported as new compounds from Z. rhoifolium and Z. nitidum, respectively. From the spectroscopic data, 2'-4' should be revised as the known compounds 2-4. In addition, the cytotoxicity of the isolates was evaluated on the MCF-7, NCI-H460 and SF-268 cell lines. Among these isolates, liriodenine (14) was shown to be the most active compound against the MCF-7, NCI-H460 and SF-268 cell lines with IC50 values of 2.19, 2.38, and 3.19 µg/mL, respectively. |
