Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.
Electrophoresis. 2012 Jul;33(14):2102-11. doi: 10.1002/elps.201200080.
The formation and properties of carbonate adducts of some organic hydroxy compounds in aqueous medium were investigated. Fatty alcohols and sugars were chosen as representative classes of biological interest, and the medium was carbonated aqueous solution with pH ranging from 3.0 to 8.3. Capillary electrophoresis with two capacitively coupled contactless conductivity detectors (C⁴ Ds) was used for quantitation and to obtain the mobility of the monoalkyl carbonates (MACs), which were used to determine the equilibrium and kinetic constants of the reaction as well as the diffusion coefficients. For increasing chain length of the alcohols, the equilibrium constant tends to the unit, which suggests that fatty alcohols can form the corresponding MACs. The formation of MACs for cyclohexanol and cyclopentanol also suggest the existence of similar species for sterols. Carbonate adducts of fructose, glucose, and sucrose were also detected, which suggests that these counterparts of the well-known phosphates can also occur in the cytosol. Our calculations suggest that one in 1000 to one in 10,000 molecules of these hydroxy compounds would be available as the corresponding MAC in such a medium. Experiments carried out at pH values less than 3.0 showed that there is a catalytic effect of hydronium on the interconversion of bicarbonate and a MAC. Taking into account the great number of hydroxy compounds similar to the ones investigated and that bicarbonate is ubiquitous in living cells, one can anticipate the existence of a whole new class of carbonate adducts of these metabolites.
研究了一些有机羟化合物在水介质中与碳酸盐形成加合物的情况。选择脂肪醇和糖作为具有代表性的生物感兴趣的类，介质为 pH 值在 3.0 到 8.3 之间的碳酸化水溶液。采用带有两个电容耦合非接触电导检测器（C4 Ds）的毛细管电泳进行定量，并获得单烷基碳酸盐（MACs）的迁移率，用于确定反应的平衡和动力学常数以及扩散系数。对于醇链长的增加，平衡常数趋于单位，这表明脂肪醇可以形成相应的 MACs。环己醇和环戊醇的 MACs 的形成也表明固醇中存在类似的物质。还检测到果糖、葡萄糖和蔗糖的碳酸盐加合物，这表明这些众所周知的磷酸盐的类似物也可以存在于细胞质中。我们的计算表明，在这样的介质中，这些羟化合物中有 1/1000 到 1/10000 的分子可以作为相应的 MAC 存在。在 pH 值小于 3.0 的实验表明，氢离子对碳酸氢盐和 MAC 之间的相互转化有催化作用。考虑到与所研究的化合物相似的羟化合物数量众多，并且碳酸氢盐在活细胞中无处不在，可以预料到这些代谢物的碳酸盐加合物将形成一个全新的类别。
