云南甘草中新三萜皂甙元的结构鉴定

NEW TRITERPENOIDAL SAPOGENINS FROM THE ROOTS OF GLYCYRRHIZA YUNNANENSIS

从云南甘草(Glycyrrhiza yunnanensis)根中分离出10个化合物。本文报道其中二个新三萜皂甙元,云南甘草皂甙元A和B(glyyunnansapogenin A and B),以及已知化合物β-谷甾醇的鉴定。云南甘草皂甙元A和B的结构经衍生物制备,红外,核磁共振氢谱、碳谱和质谱等光谱测定和解析、分别推定为3β,24-dihydroxy-16-oxo-olean-12-en-29-oic acid和3β,21α,24-trihydroxy-olean-12-en-30-oic acid。

Two new pentacyclic triterpenoidal sapogenins of oleanane type, namely glyyunnansapogenin A(Ⅰ) and glyyunnansapogenin B (Ⅱ), together with a known compound β-sitosterol were isolated and characterized from the roots of Glyeyrrhiza yunnanensis Cheng f. et L. K. Tai, family Leguminosae, collected in Yunnan Province, China. Ⅰ was obtained as its methyl ester (Ⅰ_a), mp 276～277℃, which formed a diacetate (Ⅰ_c), mp 244～245℃. Ⅱ, mp 287～289℃, gave a triacetate (Ⅱ_b); mp 286～287℃ and a monomethyl ester (Ⅱ_a), mp 272～275℃, which further formed a triacetate (Ⅱ_c), mp 187～189℃ and a diacetate (Ⅱ_d), mp 243～245℃ 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, ~1HNMR, ^(13)CNMR, MS, CD and ORD. Glyyunnansapogenin A (Ⅰ)was proved to be 3β, 24-dihydroxy-16-oxo-olean-12-en-29-oic acid and glyyunnansapogenin B (Ⅱ) 3β, 21α, 24-trihydroxy-olean-12-en-30-oic acid respectively.