Transformations, NMR studies and biological testing of some 17β-isoxazolyl steroids and their heterocyclic ring cleavage derivatives

The synthesis and NMR structure analysis of a group of oxygenated steroids containing isoxazole, dihydrofuran, tetrahydrofuran rings or enamino carbonyl fragment in the side chain have been fulfilled. The prepared compounds were tested toward several enzymes (human cytochrome P450s CYP17, CYP19, CYP51 and CYP51 of pathogenic fungus Candida glabrata) as their potential inhibitors. A number steroids show a high level affinity (micro- and submicromole) for the enzyme-ligand complexes of the tested compounds with human CYP51, CYP19 and CYP51 of C. glabrata.