A New Isoflavan Glucoside from the Roots of Astragalus membranaceus var. mongholicus

A new isoflavan glucoside, namely astramemside A (1), together with six known compounds (2-7) were obtained from the roots of a traditional Chinese medicine, Astragalus membranaceus var. mongholicus. Their structures were elucidated by spectroscopic analyses (HRESIMS, UV, IR, 1D and 2D NMR), and the absolute configuration of 1 was determined by combination of chemical transformation and single-crystal X-ray diffraction. Compound 1 showed moderate inhibition on nitric oxide (NO) production induced by lipopolysaccharide in RAW264.7 cells with an IC50 value of 38.98 5.28 M.