87(P17) C-13 NMRグリコシド化シフト則のイリドイド配糖体絶対構造研究への応用 : シクロペンタン環上の2級あるいは3級アルコールの絶対配置とパラメータ(ポスター発表の部)

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A study has been conducted to determine the absolute stereostructure by applying the rule of glycosidation shifts in ^<13>C-NMR to iridoid glycosides that have a glycosyl group on the cyclopentane ring. The glycosyl group were classified as the secondary and tertiary hydroxyl group. Furthermore, application of the parameters to the secondary alcohol was examined and discussed by classifying as the sterically hindered case 1 and 2, and allyl alcohol. In the sugar moiety, β-D-glucose, α-D-galactose, and α-L-rhamnose, as well as disaccharides were also investigated with the parameters. Then, the new parameters for the iridoid glycosides have been established after comparing the parameter presented by Tori et al.. For nepetaside from Nepeta cataria, after applying of the substitution effects of alkanes in ^<13>C-NMR was considered, its absolute stereostructure was elucidated by applying the rule of glycosidation shifts in ^<13>C-NMR. Simultaneously, for the several patriscabrol glycosides from Valerianaceae, based on the stereostructure determined by X-ray analysis, the absolute sterostructures have made clear by applying the same rule of the glycosidation shifts in ^<13>C-NMR, respectively. The total fifteen kinds of iridoid glycosdies have been studied and discussed. We were able to obtain as extremely good results as those obtained for the ionone type glycosides reported the last time.
1997-07-20