氨羧钾调控草酸钙晶体生长及其与分子结构的关系

Regulation of Potassium Aminocarboxylates on Calcium Oxalate Crystal Growth and Its Relationship with Molecular Structure

采用扫描电子显微镜(SEM)和X射线衍射(XRD)在凝胶体系中研究了不同结构氨羧钾对草酸钙(CaOxa)结晶的影响,这些氨羧钾包括氨基乙酸钾(KGLY)、乙二醇二乙醚二胺四乙酸二钾(K2EGTA)、氨基三乙酸二钾(K2NTA)、二乙三胺五乙酸二钾(K2DTPA)、乙二胺四乙酸二钾(K2EDTA)和环已二胺四乙酸二钾(K2CDTA).这些物质均能诱导二水草酸钙(COD)形成,抑制一水草酸钙(COM)聚集和减小COM的比表面积,其诱导COD能力依次为:K2DTPA(55wt%)>K2EDTA≈K2CDTA(50wt%)>K2NTA(43wt%)>>K2EGTA(4wt%)>KGLY(2wt%),抑制COM聚集的能力依次为:K2DTPA>K2NTA>K2CDTA≈K2EDTA>K2EGTA>KGLY.从氨羧盐的分子结构、羧基的相对含量、羧基的空间位置、与钙离子的配位能力及其配位方式等角度讨论了其抑制COM聚集和诱导COD形成的化学基础.结果表明K2NTA和K2DTPA有可能成为防止草酸钙结石形成的潜在药物.

The effect of potassium aminocarboxylates on crystallization of calcium oxalate （CaOxa） was investigated in silica gel system by means of scanning electron microscopy and X-ray diffraction. These aminocarboxylates included potassium aminoacetate （KGLY）, dipotassium glycoletherdiaminotetraacetate （K2EGTA）, dipotassium aminotriacetate （K2NTA）, dipotassium diethylenetriaminepenteacetate （K2DTPA）, dipotassium ethylene aliamine tetraacetate （K2EDTA） and dipotassium cyclohexanediamine tetraacetate （KECDTA）. All these aminocarboxylates could induce the formation of calcium oxalate dihydrate （COD）, inhibit the aggregation of calcium oxalate monohydrate （COM） and decrease the specific surface area of COM aggregates. The ability to induce COD formation follows the order： K2DTPA （55wt%） 〉 KEEDTA ≈KECDTA （50wt%） 〉 K2NTA （43wt%） 〉〉 KEEGTA （4wt%） 〉 KGLY （2wt%）, and the ability to inhibit COM aggregation follows the sequence： K2DTPA〉K2NTA 〉 K2CDTA≈ K2EDTA 〉 K2EGTA 〉 KGLY. These results are discussed in terms of their molecular structure, relative content of carboxylic groups, spatial location of carboxyl groups in aminocarboxylates, and their coordination capacity and modes with Ca^2＋ ions. It is proved that K2NTA and K2DTPA can be the potential drugs for preventing the formation of CaOxa stones.