A new Amaryllidaceae alkaloid from the bulbs of Lycoris radiata

Abstract

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 2α-methoxy-6-O-ethyloduline (1), together with nine known alkaloids 2α-methoxy-6-O-methyloduline (2), trispherine (3), 8-O-demethylhomolycorine (4), homolycorine (5), 9-O-demethylhomolycorine (6), oduline (7), lycorenine (8), 6α-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 μg·mL-1 and CC50 values of 14.37, 4.79, and 80.12 μg·mL-1, respectively.

Keywords: 2α-Methoxy-6-O-ethyloduline; 2α-Methoxy-6-O-methyloduline; Amaryllidaceae alkaloids; Homolycorine-type; Lycoris radiata.