Chemical components of Aconitum barbatum var. puberulum and their cytotoxic and antibacterial activities

Nineteen compounds, including seventeen alkaloids O-methylarmepavine (1), (S)-6-methoxy-1-(4-methoxybenzyl)-2-methyl -1,2,3,4-tetrahydroisoquinolin-7-ol (2), (+)-(IR,laR)-lahydroxymagnocurarin (3), (6R,6aS,P)-(+)-corydine (4), (+)-N-methyllaurotetanine (5), magnoflorine (6), 3-hydroxy-1,2-dimethoxy-5-methyl-5H-dibenzoindol-4-one (7), imperialine (8), crispine B (9), (S)-1-(3-methoxyphenyl)-N-methylpropan-2-amine (10), methyl 2- (acetamino)benzoate (11), 2-carboxyoxanilic acid methylester (12), 4-[2-(methoxycarbonyl) anilino]-4-oxobutanoic acid methyl ester (13), N-methylcorydaldine (14), N-methyl-6,7- dimethoxyisoquinolone (15), (5S,6R,7S,8R)-5-amino-(2Z,4Z)-1,2,3-trihybuta-2,4-dienyloxypentane- 6,7,8,9-tetraol (16), nicotinic acid (17), and two megastigmane type compounds, S(+)- dehydrovomifoliol (18) and megastigmane (19), were isolated from the Aconitum barbatum var. puberulum Ledeb. Compounds 1-3 and 5-19 were isolated from this plant for the first time, of which compound 11 was isolated from natural source for the first time. Cytotoxicity evaluation revealed that compound 5 displayed mild cytotoxicity against the Hela cell lines (IC50 13.69 ± 0.036 μM). Antibacterial activity evaluation revealed that compounds 1 and 6 showed strong antibacterial activity against the Gram-positive bacterium, S. aureus.