np3005425_si_003.pdf (1.12 MB)
Cytotoxic Alkaloids from the Whole Plants of Zephyranthes candida
journal contribution
posted on 2012-12-28, 00:00 authored by Zengwei Luo, Fuqian Wang, Jinwen Zhang, Xingyao Li, Mengke Zhang, Xincai Hao, Yongbo Xue, Yan Li, F. David Horgen, Guangmin Yao, Yonghui ZhangSeven new alkaloids, N-methylhemeanthidine
chloride
(1), N-methyl-5,6-dihydroplicane (5), O-methylnerinine (6), N-ethoxycarbonylethylcrinasiadine (7), N-ethoxycarbonylpropylcrinasiadine (8), N-phenethylcrinasiadine (9), and N-isopentylcrinasiadine (10), together with eight known
alkaloids, hemeanthamin (2), 3-epimacronine (3), (+)-tazettine (4), N-methylcrinasiadine
(11), trisphaeridine (12), 5,6-dihydrobicolorine
(13), lycorine (14), and nigragillin (15), were isolated from the whole plants of Zephyranthes
candida. The structures of the new compounds were established
by spectroscopic data interpretation, with single-crystal X-ray diffraction
analysis performed on 1. The absolute configuration of
3-epimacronine (3) was determined by single-crystal X-ray
diffraction analysis with Cu Kα irradiation. Compounds 1–15 were evaluated for their in vitro
cytotoxicity against five human cancer cell lines and the Beas-2B
immortalized (noncancerous) human bronchial epithelial cell line.
Compounds 1, 2, 9, and 14 exhibited cytotoxicity with IC50 values ranging
from 0.81 to 13 μM with selectivity indices as high as 10 when
compared to the Beas-2B cell line.