不同种类羧酸钠对草酸钙结晶过程中晶相的影响

Effect of Various Kinds of Carboxylates on Phases Compositions of Calcium Oxalate in Aqueous Solutions

采用X射线衍射法研究了水溶液中不同种类羧酸钠对尿结石主要成份草酸钙结晶的影响,这些羧酸钠分别为含有一、二、三和四个羧基的羟基乙酸钠(NaGly)、酒石酸钠(Na2Tart)、柠檬酸钠(Na3Cit)和EDTA二钠盐(Na2EDTA).结果表明,随着羧酸钠浓度的增加,草酸钙的晶相均发生规律性的变化:从最稳定的一水草酸钙(COM),到不稳定的二水草酸钙(COD),最后转化为次稳定的三水草酸钙(COT).不同结构羧酸钠抑制COM生长、促进COD生成的顺序为:Na3Cit>Na2Tart>Na2EDTA>NaGly.该结果将为临床上选择防结石药物提供新的思路.

The effects of various kinds of sodium carboxylates such as glycollate (NaGly), tartrate (Na(2)Tart), citrate (Na(3)Cit) and the disodium of EDTA (Na(2)EDTA) on the phase compositions of calcium oxalate (CaC2O4) were studied in aqueous solution and X-ray powder diffraction was used to characterize the products. The results are all showed in Table 1. It can be seen that in the presence of sodium carboxylates, the percentages of the calcium oxalate monohydrate (COM), dihydrate (COD) and trihydrate (COT) in the crystals depend on the concentration of the carboxylates. In lower concentration range only COM was precipited. In higher concentration range COD and COT were induced. The ability to inhibit the formation of COM but favor that of COD and COT follows the order: Na(3)Cit > Na(2)Tart > Na(2)EDTA > NaGly. So citrate is considered to be an effective inhibitor of curing urolithiasis. Our study can give a reference for clinical therapy.