摘要
以氢醌 (HQ)为探针 ,用循环伏安法 (CV)研究了神经递质 (neurotransmitters)分子与 β 环糊精 ( β CD)单元的包络作用 .通过在 β CD修饰电极界面上神经递质对被包络的HQ的抑制效应 ,求得各神经递质与 β CD的表面包络常数 ,该常数因神经递质所含官能团的不同而不同 ,且随链长的递增呈现有规律的递增 .以甲基橙 (MO)为探针 ,用紫外 -可见光谱法 (UV)证明溶液中神经递质分子与 β CD能有效包络 ,包络常数及其与神经递质分子结构的关系与循环伏安法的测定结果一致 .量子化学的SCF法计算得到了神经递质分子与 β CD单元包络的结构 .理论计算和实验结果表明 :疏水相互作用、范德华力及氢键等多种非共价键的弱相互作用协同贡献于包络物的形成 ,主客体间的结构匹配及溶剂效应对包络物的稳定性起重要作用 .
Inclusion of neurotransmitters (NEUROT) by SAM β CD on a gold electrode was examined by cyclic voltammetry (CV) using hydroquinone (HQ) as a probe. From the inhibitory effect of the NEUROT on the inclusion of HQ by the surface confined cyclodextrin, the association constants ( K asn ) of the NEUROT with the immobilized β CD were estimated. For comparison, the association of NEUROT with free β CD was examined spectrophotometrically using methyl orange (MO) as a probe. It is concluded that, in both free and surface confined β CD systems, the K asn values increase with an increase in the length of aliphatic branched chain and different functional group conjugated to the benzene ring of NEUROT. All structures of the inclusion compounds were obtained by full optimization at the semi empirical SCF level. The results obtained indicate that several noncovalent weak forces, including hydrophobic, van der Waals and hydrogen bonding interaction, cooperatively contribute to the formation of the complexes. The structural matching between host and vip with solvent effect plays a crucial role in the stability of the complexes.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2003年第4期597-602,共6页
Acta Chimica Sinica
基金
江苏省自然科学基金 (No.BK2 0 0 1 1 31 )
国家自然科学基金 (No.2 98351 1 0 )资助项目
