A new Amaryllidaceae alkaloid from the bulbs of Lycoris radiata

AIM:To study the Amaryllidaceae alkaloids of the bulbs of Lycoris radiata.METHODS:The chemical constituents were isolated and purified by various chromatographic techniques,and the chemical structures were elucidated on the basis of spectroscopic methods.In addition,the antiviral activities of alkaloids 1-10 were evaluated using flu virus A.RESULTS:One new homolycorine-type alkaloid 2-methoxy-6-O-ethyloduline(1),together with nine known alkaloids 2-methoxy-6-O-methyloduline(2),trispherine(3),8-O-demethylhomolycorine(4),homolycorine(5),9-O-demethylhomolycorine(6),oduline(7),lycorenine(8),6-O-methyllycorenine(9) and O-ethyllycorenine(10) were obtained.CONCLUSION:Alkaloid 1 is a new compound,and 1-3 were major alkaloids in this plant.Alkaloids 1-3 showed weak antiviral activities against flu virus A with IC50 values of 2.06,0.69,and 2.71 gmL-1 and CC50 values of 14.37,4.79,and 80.12 gmL-1,respectively.