^1H NMR选择检测新技术用于新三萜皂苷的结构研究  

Application of Novel Selective ~1H NMR Techniques to the Structural Determination of a New Triterpenoid Glycoside

作　　者：缪振春[1] 冯锐[1] 魏锋[2] 

机构地区：[1]中国人民解放军军事医学科学院毒物药物研究所,北京100850 [2]北京江中药物研究所,北京100050

出　　处：《化学学报》1999年第7期801-807,共7页Acta Chimica Sinica

摘　　要：从中药川续断根部的乙醇提取物中分得1个新的三萜皂苷,经过测定,其结构为:3-O-α-L-吡喃鼠李糖(1→3)-β-D-吡喃葡萄糖(1→3)-β-L-吡喃鼠李糖(1→2)-β-L-吡喃阿拉伯糖-常春藤苷元(1).研究表明,采用一维SEMDY和三照射NOE差谱NMR新技术相结合能以“拼凑”方式测定糖链结构.方法简便、快速,测定结果可靠,重叠的信号可以指认,并且对样品不必进行化学降解或衍生化.本方法也可用于其他类型的寡糖结构测定.A new triterpenoid saponin was isolated from the ethanolic extract of the root of Dipsacus asperoides C. Y. Cheng et T. M. A. The structure was elucidated as 3-O-a-L-rhamnopyranosyl (1 →3)-β-D-glycopyranosyl (1→3) -a-L-rhamnopyranosyl (1→2)-β-L-arabinopyranosyl-hederagenin. In the present study, 1D-SEMDY in combination with triple irradiation NOE difference spectroscopy has been successfully used for determining the glycosidation position in an aglycome moiety and the sequence of sugar moiety in the compound 1. The results obtained showed that The efficiency of magnetization transfer among the sugar residue of glycoside is much better for 1D-SEMDY than that for conventional 1D-HOHAHA and ID-multiple relay COSY experiments. For example, for sugar residues such as arabinose which have coupling of 1 ~ 1.5 Hz between 4 - H and 5 - H proton, complete 1H NMR subspectra can be obtained. This technique provides the. possibility to acquire pure-phase subspectra without the use of the Z-filter, thus allowing for identification of individual sugar components and spectra assignments in complex overlapping proton spectra. Triple irradiation NOE Difference Spectroscopy is based on the simultaneous irradiation of both lines in a doublet of the sugar anomeric proton with a low decoupling power during the preirradiation time, by which SPT and Bloch-Siegert shift effects can be removed from difference spectra.

关 键 词：中药 川续断 三萜皂苷 结构 NMR 糖链结构 测定 

分 类 号：R282.71[医药卫生—中药学] O629.61[医药卫生—中医学]