title: Corticosteroid-calcium complexes.
abstract: Glucocorticoids and calcium ions are shown to interact to yield a complex with properties that are distinct from those of the reactants. Reaction of steroids with Ca2+ appears to require the dihydroxyacetone side chain, since other structures do not react. Evidence for complex formation are: increased aqueous solubility of cortisol when Ca2+ is added to an aqueous or a biphasic aqueous/chloroform (or ethyl acetate) system; increased rate of migration of cortisol during reversed-phase thin-layer chromatography and HPLC; chromatographic comigration of 45Ca2+ and 3H-labeled cortisol; coprecipitation of 45Ca2+-3H-cortisol complexes. After dissociation of the cortisol-calcium complex, the only steroid recovered was cortisol. By the above criteria, the properties of cortisol were not affected by Sr2+, Ba2+, or Mg2+. The cleavage patterns of cortisol in the mass spectrometer corresponded to that of 11 beta-hydroxyandrostenedione when Ca2+ was present, and to cortisol in its absence. We therefore postulate that the structure of the dihydroxyacetone side chain was transiently altered by Ca2+, resulting in a labile C17-C20 bond. These results support our earlier proposal that the chemical and physico-chemical properties of corticosteroids are modified by calcium ions.
authors.affiliation: Population Council, New York, NY 10021.
authors.forename: C
authors.initials: C
authors.lastname: Monder
authors.forename: F
authors.initials: F
authors.lastname: Iohan
authors.forename: A
authors.initials: A
authors.lastname: Marandici
mesh_terms: D000305:Adrenal Cortex Hormones / Q000378:metabolism*; D001464:Barium / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D008274:Magnesium / Q000378:metabolism; D013058:Mass Spectrometry; D012997:Solvents; D013324:Strontium / Q000378:metabolism
chemical_list: D000305:Adrenal Cortex Hormones; D012997:Solvents; D001464:Barium; D008274:Magnesium; D002118:Calcium; D013324:Strontium