Oleanane type saponins from the stems of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao

Astragalus membranaceus is a Traditional Chinese Medicine (TCM) belonging to the Leguminosae family. It has been used as antidiabetic, cardioprotective, and hepatoprotective in the TCM clinic. From the stems of A. membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao, 14 oleanane type saponins (1-14) including eight new ones, astroolesaponins A (1), B (2), C1 (3), C2 (4), D (5), E1 (6), E2 (7), and F (8) were obtained, and their structures were elucidated by chemical and spectroscopic methods. Compounds 1-5, 7, 8, 11, and 13 showed decreased effects on triglyceride levels in sodium oleate induced HepG2 cells.