Calycosin 7-O-<Emphasis Type="Italic">β</Emphasis>-D-glucopyranoside,an anti-HIV agent from the roots of <Emphasis Type="Italic">Astragalus membranaceus</Emphasis> var. <Emphasis Type="Italic">mongholicus</Emphasis>
(1) Shanghai Institute of Materia Medica, Shanghai Institute for Biological Science, Chinese Academy of Sciences, Shanghai, 201203, China;(2) Laboratory of Molecular Immunopharmacology, Chinese Academy of Sciences, Kunming, 650223, China