Five New Steroidal Compounds from Ypsilandra thibetica

Five new steroids, including the four new steroidal saponins ypsilandroside B ( 1 ), ypsilandroside A ( 2 ), isoypsilandroside A ( 4 ), and isoypsilandroside B ( 5 ), as well as the new steroidal sapogenin isoypsilandrogenin ( 3 ), were isolated from the whole plant of Ypsilandra thibetica Franch . Their structures were determined on the basis of spectroscopic analyses, including extensive 2D‐NMR techniques. The structure and relative configuration of ypsilandroside B (=(3 β ,12 α ,25 R )‐3‐[( α ‐ L ‐rhamnopyranosyl‐(1→2)‐ β ‐ D ‐apiofuranosyl)oxy]spirost‐5‐ene‐12,27‐diol; 1 ) was unequivocally determined by single‐crystal X‐ray diffraction. The antifungal and antibacterial activities of 1 – 5 towards various types of fungi and bacteria are reported.