四川九节龙中新五糖三萜皂苷结构的NMR研究

NMR STUDY ON A NEW TRITERPENOID GLYCOSIDE OF ARDISIA PUSILLA

从四川九节龙（ Ａｒｄｉｓｉａ ｐｕｓｉｌｌａ Ａ．ＤＣ） 的正丁醇提取物中分得一个三萜皂苷．经过测定，它为：３Ｏ［βＤ吡喃木糖（１ →２）βＤ吡喃葡萄糖（１ →４）］［βＤ吡喃葡萄糖（１ →２）βＤ吡喃葡萄糖（１ →２）］αＬ吡喃阿拉伯糖仙客来亭Ａ，为一新五糖皂苷（１） ．糖体间和糖体与苷元间的连接顺序和连接位置采用一维ＳＥＭＤＹ 和旋转坐标系ＮＯＥ 差谱核磁共振新技术相结合的方法进行了研究．结果表明，这一方法用于测定寡糖链结构具有准确、简便、快速等特点，对化合物不需要进行化学降解或衍生化，糖基的重叠１Ｈ ＮＭＲ

Anew triterpenoid saponin wasisolated from Ardisia pusilla A.DC. which has im provedim munologicaland antitumoranditsstructure established as 3 O [β D xylopyranosyl(1 →2) β D glucopyranosyl(1→4)][β D glucopyranosyl(1→2) β D glucopyranosyl(1 →2)] α L arabinopyranosyl cyclamiretin A. The results showed that the chemical structure of oligosaccharide chainsofthe saponin could be elucidated by the combination of 1D SEMDY and NOEdifference spectroscopy in rotating frame techniques, without having recourse to chemicaldegration or modification.Completeassignmentsofseverely overlapping proton res onance ofthesugarresidues were obtained.