摘要
用循环伏安法和计时库仑法研究了维生素Ｂ＿６（ＶＢ＿６）在不同ｐＨ值的磷酸盐介质中的电化学行为。结果表明：ＶＢ＿６经过一个有质子参与的４ｅ不可逆电氧化反应；在碱性和中性介质中ＶＢ＿６被电氧化为含有羰基结构的自由基；在酸性介质中ＶＢ＿６被电氧化为γ－内酯。电氧化的产物均具电活性，可分别发生两步准可逆氧化还原反应。化学鉴定实验表明在碱性和中性介质中ＶＢ＿６氧化后生成羰基化合物，而在酸性介质中ＶＢ＿６氧化后无羰基生成。紫外吸收光谱电化学实验结果表明：ＶＢ＿６在碱性和中性介质条件下随电解时间而变化的吸收光谱与在酸性介质条件下的不一样。在此基础上提出了ＶＢ＿６在不同ｐＨ介质条件下可能的电化学反应历程。
The electrochemical behaviors of vitamin B6(VB6) were studied by cyclic voltammetry and chronocoulometry in different pH phosphate buffers.The results showed that VB6underwent an irreversible electrooxidation with four-electron transfer.VB6 was oxidized to a radicalwhich contained carbonyl structure in basic and neutral medium and was oxidizcd to γ-lactone in acidic medium,The electrooxidative products have electroactivity and a two step quasi-reversible redoxreaction can take place.The chemical detection showed that VB6 was oxidized to form carbonylcompound in basic and neutral medium,but not in acidic medium. The UV-SEC(spectroelectrochemistry)experiments showed that there were different absorption spectra of VB6 inbasic-neutral and acidic media with different electrolysis times.On the basis of the above results, the electrochemical reaction path way of VB6 is presented in different pH media.
出处
《药学学报》
CAS
CSCD
北大核心
1996年第6期455-460,共6页
Acta Pharmaceutica Sinica
关键词
维生素B6
循环伏安法
计时库仑法
电化学反应
Vitamin B6
Cyclic voltammetry
Chronocoulometry
Ultra-violet spectroelec-trochemistry
