麦芽酚铁、锌配合物的热力学特性及抑菌性能

Thermodynamic Characteristics and Antibacterial Properties of Maltol Complexes with Fe^(3+) and Zn^(3+)

采用水热法合成了麦芽酚锌及麦芽酚铁配合物,采用电子光谱、DSC和平板法研究了其热力学特性及抑菌活性.结果表明:麦芽酚与铁离子或锌离子配位后,其阴离子在320 nm处的吸收峰受到影响,电子光谱分别发生20或45 nm的蓝移,确证麦芽酚与铁或锌离子发生了配位;麦芽酚铁和麦芽酚锌配合物的DSC谱中各有一个放热分解峰,峰形较尖锐,峰值分别出现在293.9和143.9℃处,分解焓值分别为122.8和374.6 J/g,说明麦芽酚铁配合物的稳定性高于麦芽酚锌配合物;平板法和浊度法显示麦芽酚金属配合物对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌和藤黄微球菌4种细菌具有较好的抑菌效果,在实验浓度范围内,麦芽酚铁的抑菌能力大于麦芽酚锌,且抑菌效果由好到差依次为藤黄微球菌、大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌.文中还对配合物可能的抑菌机理进行了探讨.

Maltol complexes with zinc and iron were synthesized via the hydrothermal method, and the thermody- namic characteristics as well as antibacterial properties of the products were investigated by means of electronic spectroscopy, DSC and pour plate method. The results show that the coordination reaction between mahol and Fe（Ⅲ） or Zn（ Ⅱ ） influences the absorption peak at 320nm and results in a 20- or 45-nm blue shift of the elec- tronic spectrum, which confirm the occurrence of the coordination reaction. DSC results indicate that the two complexes both have one narrow exothermic peak with the peak value of 293.9 and 143.9 ℃, respectively, and that the enthalpy values calculated from the DSC curves are respectively about 122.8 and 374.6 J/g, which means that mahol-Fe is more stable than mahol-Zn. Moreover, the results obtained by pour plate method and optical density method show that maltol-Fe is of more excellent antibacterial property in the order of Micrococcus luteus 〉 Escherichia coli 〉 Bacillus subtilis 〉 Staphylococcus aureus. The possible antibacterial mechanism of the complexes is also discussed in the end.