四川九节龙中新四糖三萜皂苷结构和核磁共振研究

NMR and Chemical Structure of a New Saponin from Jiu Jiujlong (Ardisea Pusilla)

从四川九节龙（Ａｒｄｉｓｅａ 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：３－０－「β－Ｄ－吡喃葡萄糖（１→２）」「α－Ｌ－吡喃鼠李糖（１→３）－β－Ｄ－吡喃葡萄糖（１→３）」－α－Ｌ－吡 阿拉伯糖－仙客来亭Ａ，为一新甲糖皂苷（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。

A new triterpenoid saponin has been isolated from Ardisea pusilla A. DC, Which possesses improved immunological and antitumor activity. Its structure is deduced as3-O-[a-L- (rhamno - pyranosyl - (1→3) - β -D - lucopyranosyl - (1→3) ] [β - D - glucopyranosyl(l →2)] - a - L - arabinopyranosyl cyclamiretin A. The results obtained show that the chemical structure of oligosaccharide chains of the saponin could be elucidated by using the techniques of 1D - SEMDY and NOE difference spectroscopy in rotating frame, without recourse to chemical degration or modification. Complete assignments of severely overlapping proton resonances of the sugar residues were achieved. The sites of glycosylation and the sequence of sugars in the glycoside can be determined unambiguously.