N-去甲万古霉素亲和吸附剂的合成及性能

将N,N二甲基丙烯酰胺N,N′乙撑双丙烯酰胺共聚物部分水解,在共聚物中引入适量的羧基.含羧基的聚合物与氨基酸甲酯缩合,然后使酯基皂化,将氨基酸引入聚合物.将革兰氏阳性菌细胞壁粘肽的三种类似物(-Gly,-Gly-DAla,-Gly-DAla-DAla)分别引入上述聚合物,合成了3种万古霉素系列抗菌素的亲和吸附剂(Ⅰ,Ⅱ和Ⅲ).结果表明,吸附剂Ⅱ和吸附剂Ⅲ对N去甲万古霉素的吸附量分别为0.80和0.86mmol/g;最佳吸附pH值为6左右;吸附剂Ⅰ的吸附量随着吸附液中盐浓度的增加而显著降低,而吸附液中盐浓度对吸附剂Ⅱ的吸附量影响较小.说明亲和作用在吸附剂Ⅱ的吸附中贡献较大.用0.4mol/LNa₂CO₃(pH9.5)/CH₃CN(体积比为7/3)作为洗脱剂可完全脱附被吸附的N去甲万古霉素.

Synthesis and Characterization of Affinity Adsorbents for N-Demethylvancomycin

Copolymer of N,N-dimethylacrylamide and N,N′-ethylene bisacrylamide was partially hydrolyzed to introduce the carboxyl groups onto the copolymer. Amino acids were introduced onto the carboxyl group-containing copolymer by coupling the methyl ester of the amino acids with the copolymer and then saponifying the ester. In this way, three analogues(-Gly, -Gly-D-Ala, -Gly-D-Ala-D-Ala) of the cell wall mucopeptide of Gram-positive bacteria were introduced onto the copolymer and three affinity adsorbents (Adsorbents Ⅰ, Ⅱ and Ⅲ) for vancomycin group of antibiotics were synthesized. The results showed that the adsorption capacities of adsorbents Ⅱ and Ⅲ for N-demethylvancomycin were 0. 80 and 0.86 mmol/g, respectively. The optimal pHfor the adsorption was about 6. The effect of the salt(NaCl) concentration in the solution on the adsorption capacities of adsorbents Ⅰ and Ⅱ indicated that the capacity of adsorbent Ⅰ decreased markedly with increasing the salt concentration, while the effect of the salt concentration on the capacity of adsorbent Ⅱ was relatively slight. The result suggested that the affinity interaction contributed to the adsorption of adsorbent Ⅱ was greater than that of adsorbent Ⅰ. The adsorbed N-demethylvancomycin was completely desorbed by 0.4 mol/L Na₂CO₃(pH9.5)/CH₃CN(7/3 in volume ratio).