Alkaloids from Cynanchum komarovii with inhibitory activity against the tobacco mosaic virus

A pyrroloisoquinoline alkaloid, 2,3-dimethoxy-6-(3-oxo-butyl)-7,9,10,11,11a,12-hexahydrobenzo[f]pyrrolo[1,2-b]isoquinoline (1), whose structure was determined by spectroscopic methods, was isolated from the aerial parts of Cynanchum komarovii, together with two known alkaloids. 7-demethoxytylophorine (2) and 7-demethoxytylophorine N-oxide (3). Alkaloids 2 and 3 had antiviral activities against tobacco mosaic virus. (C) 2001 Elsevier Science Ltd. All rights reserved.