Abstract: On the basis of prophase studies in our laboratory,it was found that Lycoris radiata alkaloids had strong resistance activity against tobacco mosaic virus (TMV). In order to further study the mechanism of action,studyon the chemical compositions of L.radiate was carried out in this study.As a result,eleven compounds were isolated from L.radiate. Their structures were identified by ¹H NMR, ¹³C NMR,2D NMR and HR-ESI-MS as pancratinine D (1),hippeastrine (2),O-demethylhomolycorine (3),6α-O-methyllycorenine (4),lycoramine (5),tazettine (6),lycorine (7),lycoramine N-O-xide (8),O-demethylgalantamine (9),dihydrolycorine (10)and crinine (11).In addition,the anti-TMV activity of 1,3 and 10 were evaluated in vitro by inoculating half leaf method.All of them showed anti-TMV activity.The inhibition rate of 3 exceed positive control ningnanmycin.

Key words: tobacco mosaic virus, Lycoris radiata, alkaloids, anti-TMV activity