系列低聚褐藻酸铜、锌络合物的制备及结构表征

Synthesis and characterization of series oligomeric alginic copper and zinc complexes

目的制备系列低聚褐藻酸铜(II)、锌(II)络合物,为抗菌活性筛选提供物质基础。方法以低聚甘露糖醛酸和硫酸铜为原料,以络合物中铜含量为考察指标,通过正交实验,从反应时间、pH、温度3个方面对制备工艺进行了考察,利用高效液相色谱法(HPGPC)测定了络合物重均分子量及分布系数D,利用红外光谱(IR)、扫描电镜(SEM)、圆二色谱(CD)对络合物进行了结构表征。结果正交实验表明当反应温度为70℃,pH=8~9,反应时间为1.5h时,所制备络合物中金属离子含量最高。根据最佳工艺条件制备了系列低聚褐藻酸铜、锌络合物,并对络合物进行了结构表征。结论结构表征表明低聚褐藻酸能够与铜、锌发生络合获得多糖金属络合物,但不同结构、不同M/G的低聚褐藻酸对不同金属的络合能力不同,导致所制备系列络合物金属元素含量差异较大,其中铜离子的络合量为2.5%~7.0%,锌离子的络合量为0.5%~2.1%。

Objective To prepare a series of oligomeric alginic copper（II）and zinc（II）complexes for antimicrobial activity screening.Methods Using oligomeric mannuronic acid and copper sulfate as reactants,the complex preparation method was optimized by orthogonal test.The effects of reaction time,pH,and temperature on the metal content of complex were investigated.Molecular weight was determined by HPGPC.The complexes were characterized by infrared spectroscopy（IR）,scanning electron microscopy（SEM）,circular dichroism（CD）.Results The metal ion content of the complexes was the highest when the reaction condition was as follows：reaction temperature 70 ℃,pH=8-9,reaction time 1.5h.Using the optimal process conditions,a series of oligomeric alginic acid copper and zinc complexes were prepared and then analyzed.Conclusion The structural characterization showed that oligomeric alginic acids could complex copper and zinc.But the metal complexing ability of different M/G oligomeric alginic acid was different,which resulted different metal ion content in complexes.The amount of complexed copper ion was 2.5% to 7.0%,and the amount of complexed zinc ion was 0.5% to 2.1%.