Abstract
We previously reported the separation and identification for the major metabolites from incubating medroxyprogesterone acetate (MPA) with P450. The structure assignments for these metabolites were tentatively assigned based on one-dimensional (1D) proton NMR. Unambiguous structure identification of these metabolites is critical to study biological pathways of P450. Here we report the complete structure elucidation by extensive two-dimensional (2D) NMR for the three major metabolites isolated in our earlier studies. The three major metabolites (namely M-2, M-3, M-4) were unambiguously identified to be 6β-, 1β-, and 2β-hydroxy MPA. The current work confirmed the speculated structures for these metabolites in our previous studies. More importantly, the unambiguous structural information and the establishment for their NMR chemical shifts of these metabolites can serve as reference standards for future studies.
