Rauvomines A and B, Two Monoterpenoid Indole Alkaloids from Rauvolfia vomitoria

Two unusual normonoterpenoid indole alkaloids rauvomine A (1) and rauvomine B (2), together with two known compounds peraksine (3) and alstoyunine A (4), were isolated from the aerial parts of Rauvolfia vomitoria. The structures with absolute configurations of 1 and 2 were elucidated by spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism (ECD) calculations. Compound 2 is a novel C18 normonoterpenoid indole alkaloid with a substituted cyclopropane ring that forms an unusual 6/5/6/6/3/5 hexcyclic rearranged ring system. The plausible biogenetic pathways of 1 and 2 were proposed. Compound 2 exhibited significant anti-inflammatory activity.

本研究从催吐萝芙木（Rauvolfia vomitoria）的地上部分中分离得到2个罕见的去甲单萜吲哚生物碱（normonoterpenoid indole alkaloids）——rauvomine A（1）与rauvomine B（2），以及2个已知化合物peraksine（3）和alstoyunine A（4）。通过波谱分析、单晶X射线衍射以及电子圆二色谱（electronic circular dichroism，ECD）计算，阐明了化合物1和2的结构及其绝对构型。化合物2为一类新型C18型去甲单萜吲哚生物碱，其含有取代环丙烷环，构建出罕见的6/5/6/6/3/5六环重排环系。本研究提出了化合物1和2合理的生源合成途径。化合物2表现出显著的抗炎活性。