Structural studies of loteprednol etabonate and other analogs of prednisolone using NMR techniques.
Several structural analogs of prednisolone, prepared by esterification of the carboxylic and/or the C(17)-hydroxy group of 11 beta, 17 alpha-dihydroxy-3-oxo-androsta-1,4-diene-17 beta-carboxylic acid, were investigated by NMR. Step-by-step analysis of the 1H and 13C NMR spectra of these steroids, including proton-proton selective decoupling, nuclear Overhauser effect difference spectra, attached proton test, proton-carbon correlation (HETCOR), proton-proton correlation (COSY), and long-range proton-carbon decoupling (INAPT) techniques, led to unequivocal assignments of all their proton and carbon resonances. The stereochemical structure of loteprednol etabonate (chloromethyl 17 alpha-ethoxycarbonyloxy-11 beta-hydroxy-3-oxoandrosta-1,4-diene-17 beta-carboxylate, 1), a soft corticosteroid antiinflammatory drug, was proved to be analogous to prednisolone.
Rachwal
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Pharmos Corporation, Alachua, Florida 32615, USA.
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Brewster
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D000730:Androstadienes / Q000138:chemical synthesis / Q000737:chemistry*; D000069559:Loteprednol Etabonate; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011239:Prednisolone / Q000031:analogs & derivatives* / Q000737:chemistry*; D013329:Structure-Activity Relationship
D000730:Androstadienes; D011239:Prednisolone; D000069559:Loteprednol Etabonate