Ypsilandrosides U-Y, five new steroidal saponins from Ypsilandrathibetica

Phytochemical reinvestigation on the whole plants of Ypsilandra thibetica obtained four new spirostanol glycosides, named ypsilandrosides U-X (1–4), and one new cholestanol glycoside, named ypsilandroside Y (5). Their structures have been established by extensive spectroscopic data and chemical methods. Among them, compound 4 is a rare spirostanol glycoside which possesses a novel 5(6 → 7) abeo-steroidal aglycone, while compound 1 is a first spirostanol bisdesmoside attached to C-3 and C-12, respectively, isolated from the genus Ypsilandra. The induced platelet aggregation activity of the isolates was tested. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13659-022-00337-0.