[New triterpenoidal sapogenins from the roots of Glycyrrhiza yunnanensis]

Abstract

Two new pentacyclic triterpenoidal sapogenins of oleanane type, namely glyyunnansapogenin A (I) and glyyunnansapogenin B (II), together with a known compound beta-sitosterol were isolated and characterized from the roots of Glycyrrhiza yunnanensis Cheng f. et L. K. Tai, family Leguminosae, collected in Yunnan Province, China. I was obtained as its methyl ester (Ia), mp 276-277 degrees C, which formed a diacetate (Ic), mp 244-245 degrees C. II, mp 287-289 degrees C, gave a triacetate (IIb), mp 286-287 degrees C and a monomethyl ester (IIa), mp 272-275 degrees C, which further formed a triacetate (IIc), mp 187-189 degrees C and a diacetate (IId), mp 243-245 degrees C after treatment with acetic anhydride and pyridine over night at room temperature. The structures of I and II were established by spectral analyses of IR, 1H NMR, 13CNMR, MS, CD and ORD. Glyyunnansapogenin A (I) was proved to be 3 beta, 24-dihydroxy-16-oxo-olean-12-en-29-oic acid and glyyunnansapogenin B (II) 3 beta, 21 alpha, 24-trihydroxy-olean-12-en-30-oic acid respectively.