2D　NMR与分子力学计算研究带R＿F长链麦芽糖的溶液构象

DETERMINATION OF CONFORMATION OF A R_F-MALTOSE IN SOLUTION BY NMR AND MOLECULAR MECHANICS CALCULATIONS

本文研究带Ｒ＿Ｆ长链的麦芽糖在ＤＭＳＯ中的溶液构象。从一系列ＮＯＥＳＹ谱算得８对Ｈ－Ｈ之间的距离。分子力学计算中，根据能量最低原则，算得φ＿（ｏｃ１＇ｏｃ４）角为８９．４°，中φ＿（ｏｃ６ｃ５ｏ）（及φ＿（ｏｃ６＇ｃ５＇ｏ）角）角为－１７７．２°时的构象最为稳定，从这一稳定构象读得的相应８对Ｈ－Ｈ间的距离与ＮＯＥＳＹ的结果符合。

The conformation of 1-OCH_2CH_2C_8F_(16)Cl-maltose in solution has been deter-mined by a combination of 2D NMR and molecular mechanics methods．From aseries of NOESY expcriments，one with τ_m＝400 ms was selected for H－H distancescalculation.The molecular mechanics calculation started with the sugar-rings inchair-form，CH_3 used instead of R_F group．Conformer 1 is convinced as the stableone in polar solvents by energy minimization. Good agreement is observed betweenthe calculated and expermental H-H distances of conformer 1.