Author/Authors :
Zhang، نويسنده , , Zhijun and Yang، نويسنده , , Jing and He، نويسنده , , Juan and Wu، نويسنده , , Xing-De and Shao، نويسنده , , Li-Dong and Li، نويسنده , , Yan and Huang، نويسنده , , Sheng-Xiong and Li، نويسنده , , Rong-Tao and Zhao، نويسنده , , Qin-Shi، نويسنده ,
Abstract :
Two new monoterpenoid indole alkaloids, vincamajorines A (1) and B (2), were isolated from Vinca major. Their structures were elucidated by means of 1D and 2D NMR, and HREIMS spectroscopic data. The relative and absolute configurations were deduced by comparing the experimental 13C NMR, ECD spectra, and OR data with those theoretically calculated. Vincamajorine A (1) represents a new C20 carbon skeleton arranged compactly in seven rings, and vincamajorine B (2) is an alkaloid with an unprecedented 6/5/7/5/6 pentacyclic ring system. A possible biosynthetic pathway was also proposed for the formation of 1 and 2.
