title: Imitation of phase I oxidative metabolism of anabolic steroids by titanium dioxide photocatalysis.
abstract: The aim of this study was to investigate the feasibility of titanium dioxide (TiO2) photocatalysis for oxidation of anabolic steroids and for imitation of their phase I metabolism. The photocatalytic reaction products of five anabolic steroids were compared to their phase I in vitro metabolites produced by human liver microsomes (HLM). The same main reaction types - hydroxylation, dehydrogenation and combination of these two - were observed both in TiO2 photocatalysis and in microsomal incubations. Several isomers of each product type were formed in both systems. Based on the same mass, retention time and similarity of the product ion spectra, many of the products observed in HLM reactions were also formed in TiO2 photocatalytic reactions. However, products characteristic to only either one of the systems were also formed. In conclusion, TiO2 photocatalysis is a rapid, simple and inexpensive method for imitation of phase I metabolism of anabolic steroids and production of metabolite standards.
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56 (Viikinkaari 5E), FI-00014, Finland. Electronic address: miina.ruokolainen@helsinki.fi.
authors.forename: Miina
authors.initials: M
authors.lastname: Ruokolainen
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56 (Viikinkaari 5E), FI-00014, Finland.
authors.forename: Minna
authors.initials: M
authors.lastname: Valkonen
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56 (Viikinkaari 5E), FI-00014, Finland. Electronic address: tiina.sikanen@helsinki.fi.
authors.forename: Tiina
authors.initials: T
authors.lastname: Sikanen
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56 (Viikinkaari 5E), FI-00014, Finland; Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55 (A.I. Virtasen aukio 1), FI-00014, Finland. Electronic address: tapio.kotiaho@helsinki.fi.
authors.forename: Tapio
authors.initials: T
authors.lastname: Kotiaho
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56 (Viikinkaari 5E), FI-00014, Finland. Electronic address: risto.kostiainen@helsinki.fi.
authors.forename: Risto
authors.initials: R
authors.lastname: Kostiainen
mesh_terms: D002384:Catalysis; D006801:Humans; D006900:Hydroxylation / Q000502:physiology; D050216:Metabolic Detoxication, Phase I / Q000502:physiology*; D008862:Microsomes, Liver / Q000378:metabolism; D010084:Oxidation-Reduction; D013256:Steroids / Q000378:metabolism; D014025:Titanium / Q000378:metabolism*
chemical_list: D013256:Steroids; C009495:titanium dioxide; D014025:Titanium
keywords: Biomimetics; Mass spectrometry; Metabolism; Oxidation; Steroids; Titanium dioxide photocatalysis