The structure of Palau'amide, a potent cytotoxin from a species of the marine cyanobacterium Lyngbya
The structure of Palau'amide, a potent cytotoxin from a species of the marine cyanobacterium Lyngbya
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DOI：
10.1021/np034001r
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发表时间：
2003-12-01
影响因子：
5.1
通讯作者：
Paul, VJ
中科院分区：
文献类型：
--
作者：
Williams, PG;Yoshida, WY;Paul, VJ
对来自帕劳的鞘丝藻属物种的提取物进行生物测定引导的分级分离，产生了帕劳酰胺（1），其对KB细胞的IC（50）值为13 nM。1的结构通过在多种溶剂中的NMR分析来阐明。特别是，梯度增强的频带选择性HMBC实验允许明确分配HMBC相关性的碳信号，分离0.1 ppm。通过对α-甲氧基苯乙酸（MPA）衍生物的NMR分析和1的降解产物的手性HPLC测定了9个手性中心中除一个（C-37）外的所有手性中心的相对立体化学和绝对构型。详细讨论了C-37位的S而不是R立体化学的归属。
Bioassay-guided fractionation of the extract of a species of Lyngbya from Palau has yielded Palau'amide (1), which had an IC(50) value of 13 nM against KB cells. The structure of 1 was elucidated by NMR analysis in a variety of solvents. In particular, a gradient-enhanced band-selective HMBC experiment allowed unambiguous assignment of HMBC correlations to carbon signals that were separated by 0.1 ppm. The relative stereochemistry and the absolute configurations of all but one (C-37) of the nine chiral centers were determined by NMR analysis of the alpha-methoxyphenylacetic acid (MPA) derivatives and chiral HPLC of the degradation products of 1. The assignment of S rather than R stereochemistry at C-37 is discussed in detail.