Palmer J, Atkinson S, Yoshida W Y, Stalcup A M, Landers J P
Department of Oceanography, University of Hawai'i at Manoa, Honolulu, USA.
Electrophoresis. 1998 Nov;19(16-17):3045-51. doi: 10.1002/elps.1150191642.
Separation of endogenous 17- or 18-hydroxylated corticosteroids (of the 21-hydroxylated 4-pregnen series) as charged chelates in capillary electrophoresis with borate as the ligand is demonstrated. Aldosterone, 18-hydroxycorticosterone, 18-hydroxy-11-deoxycorticosterone, cortisone, cortisol, and 11-deoxycortisol are separated and resolved by 400 mM borate buffer at pH 9.0. Separation characteristics of the corticosteroid charged chelates were examined by varying the separation buffer borate concentration, pH, ionic strength, and addition of organic modifiers. The borate ion [B(OH)4]- is identified as the critical buffer component. Corticosteroids chelate borate with proximal hydroxyls composed of either the 17- or 18-hydroxyl in combination with the 21-position hydroxyl. Corticosteroid/borate chelation as indicated by CE results is corroborated with 11B-nuclear magnetic resonance (11B-NMR) spectra. Chelation is a readily reversible process, with the strength of the resultant chelate, as opposed to the charge-to-mass ratio, predominantly determining analyte mobility in charged chelate - capillary electrophoresis (CC-CE).
本文证明了在以硼酸盐为配体的毛细管电泳中，可将内源性17-或18-羟基化皮质类固醇（21-羟基化孕甾系列）分离为带电螯合物。在pH 9.0的400 mM硼酸盐缓冲液中可分离醛固酮、18-羟基皮质酮、18-羟基-11-脱氧皮质酮、可的松、皮质醇和11-脱氧皮质醇。通过改变分离缓冲液的硼酸盐浓度、pH值、离子强度以及添加有机改性剂，研究了皮质类固醇带电螯合物的分离特性。硼酸根离子[B(OH)4]-被确定为关键的缓冲成分。皮质类固醇与由17-或18-羟基与21位羟基组合而成的近端羟基螯合硼酸盐。毛细管电泳（CE）结果表明的皮质类固醇/硼酸盐螯合作用通过11B核磁共振（11B-NMR）光谱得到证实。螯合是一个易于逆转的过程，与电荷质量比相反，所得螯合物的强度主要决定了带电螯合毛细管电泳（CC-CE）中分析物的迁移率。
