Angiotensin converting enzyme (ACE) inhibitory alkaloids from Fritillaria ussuriensis.

Bioassay-guided fractionation of the BuOH-soluble extract of Fritillaria ussuriensis afforded verticinone ( 1), verticine ( 2), and peimisine ( 3). Purification of these compounds was achieved with the use of various chromatographic methods. The structures of the compounds were identified on the basis of MS and NMR data analysis. Compounds 1 - 3 inhibited angiotensin I converting enzyme activity in a dose-dependent manner, displaying 50 % inhibitory concentration values of 165.0 microM, 312.8 microM, 526.5 microM, respectively. The presence of these active substances may be responsible, at least in part, for the antihypertensive action of the bulbs of Fritillaria ussuriensis.