Department of Chemistry, Faculty of Science , University of Malaya , 50603 Kuala Lumpur , Malaysia.
Institute of Biological Sciences, Faculty of Science , University of Malaya , 50603 Kuala Lumpur , Malaysia.
J Nat Prod. 2019 Jul 26;82(7):1902-1907. doi: 10.1021/acs.jnatprod.9b00255. Epub 2019 Jun 26.
Three new alkaloids were isolated from the bark extract of the Malayan , viz., arbophyllidine (), an unusual pentacyclic, monoterpenoid indole characterized by an absence of oxygen atoms and incorporating a new carbon-nitrogen skeleton, and arbophyllinines A () and B (), two pentacyclic corynanthean alkaloids incorporating a hydroxyethyl-substituted tetrahydrofuranone ring. The structures of the alkaloids were deduced based on analysis of the MS and NMR data and confirmed by X-ray diffraction analyses. The absolute configuration of arbophyllidine () was established based on experimental and calculated ECD data, while that of arbophyllinine A was based on X-ray diffraction analysis (Cu Kα). A reasonable biosynthetic route to arbophyllidine () from a pericine precursor is presented. Arbophyllidine () showed pronounced in vitro growth inhibitory activity against the HT-29 human cancer cell line with IC 6.2 μM.
从马来亚钩藤的树皮提取物中分离得到三种新的生物碱，分别为：arbophyllidine ()，一种不含有氧原子的新型五环单萜吲哚，具有新的碳-氮骨架，以及 arbophyllinines A () 和 B ()，两种五环古柯烷生物碱，具有一个羟乙基取代的四氢呋喃酮环。生物碱的结构是根据 MS 和 NMR 数据分析推导出来的，并通过 X 射线衍射分析得到证实。基于实验和计算的 ECD 数据确定了 arbophyllidine ()的绝对构型，而 arbophyllinine A 的绝对构型则基于 X 射线衍射分析（Cu Kα）确定。提出了一个从原小檗碱前体到 arbophyllidine ()的合理生物合成途径。arbophyllidine ()对 HT-29 人癌细胞系具有显著的体外生长抑制活性，IC 50 为 6.2 μM。
