Mandelalides A–D, Cytotoxic Macrolides from a New <i>Lissoclinum</i> Species of South African Tunicate
作者:Justyna Sikorska、Andrew M. Hau、Clemens Anklin、Shirley Parker-Nance、Michael T. Davies-Coleman、Jane E. Ishmael、Kerry L. McPhail
DOI:10.1021/jo3008622
日期:2012.7.20
Mandelalides A–D are variously glycosylated, unusual polyketide macrolides isolated from a new species of Lissoclinum ascidian collected from South Africa, Algoa Bay near Port Elizabeth and the surrounding Nelson Mandela Metropole. Their planar structures were elucidated on submilligram samples by comprehensive analysis of 1D and 2D NMR data, supported by mass spectrometry. The assignment of relative
Mandelalides A-D 是从南非、伊丽莎白港附近的阿尔戈亚湾和周围的纳尔逊曼德拉大都会收集的海鞘海鞘新物种中分离出的不同糖基化的、不寻常的聚酮化合物大环内酯。通过对 1D 和 2D NMR 数据的综合分析,在质谱法的支持下,在亚毫克样品上阐明了它们的平面结构。相对构型的分配是通过考虑同核和异核耦合常数以及 ROESY 数据来完成的。在水解单糖(2 - O-甲基-α - l-鼠李糖)并考虑完整天然产物中单糖和苷元之间的 ROESY 相关性。所得到的扁桃内酯 A 大环内酯的绝对构型被外推以提出扁桃内酯 B-D 的绝对构型。值得注意的是,扁桃酸 B 含有 C-4' 差向异构 2 - O - methyl -6- dehydro -α- l - talose。Mandelalides A和B显示出强的细胞毒性对人NCI-H460肺癌细胞(IC 50分别为12和44纳米,)和小鼠神经2A神经细胞瘤细胞(IC