磺胺甲嘧啶及其酰化物与低聚物的pH敏感性研究

目的:考察磺胺甲嘧啶(SM1)、磺胺甲嘧啶酰化物(SM1M)和磺胺甲嘧啶低聚物(OSM1)的pH敏感性,为将其设计成pH敏感单体提供依据。方法:制备SM1、SM1M和OSM1的NaOH溶液,采用电位滴定法,用0.01 mol/L的盐酸溶液进行滴定,测定SM1、SM1M和OSM1的解离常数(pKa)。采用紫外分光光度法,在256、270、268 nm波长处测定SM1、SM1M、OSM1在6.0、6.5、7.0、7.2、7.4、7.5、8.0 pH下的溶解度。结果:SM1、SM1M、OSM1的pKa分别为6.21、6.64、7.21;随着pH的增加,SM1、SM1M、OSM1的溶解度均有增大的趋势,但对pH变化的敏感程度表现不同。结论:SM1、SM1M和OSM1具有不同程度的pH敏感性,将其作为pH敏感单体具有一定的应用价值。

Study on pH Sensitive Properties of Sulfamerazine and Its Acylate and Oligomers

OBJECTIVE： To investigate the pH sensitive properties of sulfamerazine （SM,）, sulfamerazine acylate （SM,M） and sulfamerazine oligomers （OSM,）, and to provide reference for the design of pH sensitivity site. METHODS： NaOH solution of SM,, SM,M and OSM, were prepared, and dissociation constant （pKa） of SM,, SM1M and OSM1 were determined by potentiomet- ric titration using 0.01 mol/L hydrochloric acid. The solubility of SM,, SM,M and OSM, under the condition of pH 6.0, 6.5, 7.0, 7.2, 7.4, 7.5 and 8.0 were determined by UV spectrophotometry in 256 rim, 270 nm, 268 nm. RESULTS： The pKa of SM~, SM,M and OSM, were 6.21, 6.64 and 7.21, respectively. The solubility of SM1, SM1M and OSM1 increased with pH increasing at different levels. CONCLUSIONS： SM1, SM1M and OSMj possess pH sensitive properties at different levels obviously, holding high potential as pH sensitive units.