title: In vitro biosynthesis, isolation, and identification of predominant metabolites of 2-(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)-5,7-dimethoxyquinazolin-4(3H)-one (RVX-208).
abstract: The structures of the two predominant metabolites (M4 and M5) of RVX-208, observed both in in vitro human and animal liver microsomal incubations, as well as in plasma from animal in vivo studies, were determined. A panel of biocatalytic systems was tested to identify biocatalysts suitable for milligram scale production of metabolite M4 from RVX-208. Rabbit liver S9 fraction was selected as the most suitable system, primarily based on pragmatic metrics such as catalyst cost and estimated yield of M4 (∼55%). Glucuronidation of RVX-208 catalyzed by rabbit liver S9 fraction was optimized to produce M4 in amounts sufficient for structural characterization. Structural studies using LC/MS/MS analysis and (1)H NMR spectroscopy showed the formation of a glycosidic bond between the primary hydroxyl group of RVX-208 and glucuronic acid. NMR results suggested that the glycosidic bond has the β-anomeric configuration. A synthetic sample of M4 confirmed the proposed structure. Metabolite M5, hypothesized to be the carboxylate of RVX-208, was prepared using human liver microsomes, purified by HPLC, and characterized by LC/MS/MS and (1)H NMR. The structure was confirmed by comparison to a synthetic sample. Both samples confirmed M5 as a product of oxidation of primary hydroxyl group of RVX-208 to carboxylic acid.
authors: AMRI, 26 Corporate Circle, PO Box 15098, Albany, NY 12212-509, USA.
authors: Yuri L
authors: YL
authors: Khmelnitsky
authors: Vadim V
authors: VV
authors: Mozhaev
authors: Ian C
authors: IC
authors: Cotterill
authors: Peter C
authors: PC
authors: Michels
authors: Sihem
authors: S
authors: Boudjabi
authors: Vladimir
authors: V
authors: Khlebnikov
authors: M
authors: M
authors: Madhava Reddy
authors: Gregory S
authors: GS
authors: Wagner
authors: Henrik C
authors: HC
authors: Hansen
mesh_terms: D000818:Animals; D006801:Humans; D008862:Microsomes, Liver / Q000737:chemistry / Q000378:metabolism; D015394:Molecular Structure; D011799:Quinazolines / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D052999:Quinazolinones; D011817:Rabbits
chemical_list: D011799:Quinazolines; D052999:Quinazolinones; C000628794:apabetalone