Structural Elucidation of Human Oxidative Metabolites of Muraglitazar: Use of Microbial Bioreactors in the Biosynthesis of Metabolite Standards

Abstract

ABSTRACT:Muraglitazar (Pargluva), a dual ␣/␥ peroxisome proliferator-activated receptor activator, is currently in clinical development for treatment of type 2 diabetes. This study describes the structural elucidation of the human oxidative metabolites of muraglitazar through the use of a combination of microbial bioreactors, NMR and accurate mass analyses, and organic synthesis. Plasma, urine, and feces were collected from six healthy subjects following oral administration of 14 C-labeled muraglitazar (10 mg, 100 Ci) and pooled samples were analyzed. Approximately 96% of the recovered radioactive dose was found in the feces and 3.5% in the urine.

Involvement of Multiple Cytochrome P450 and UDP-Glucuronosyltransferase Enzymes in the in Vitro Metabolism of Muraglitazar

“…This region included the Odealkylated metabolite M1. Since there was a minimal amount of M1 found in vivo in humans after oral administration of [ 14 C]muraglitazar Zhang et al, 2006), M1 and other radioactive peaks eluting in this region were not further characterized. In the presence of UDPGA, M13 was formed as a single metabolite in the HLM incubation.…”

“…14 C]muraglitazar underwent extensive metabolism by both oxidation and glucuronidation pathways Zhang et al, 2006). Fecal excretion was the major elimination pathway for […”

“…For formation of a metabolite, % Inhibition ϭ (amount of the metabolite in the absence of inhibitor Ϫ amount of the metabolite in the presence of inhibitor)/ (amount of the metabolite in the absence of inhibitor). Zhang et al, 2006). a Metabolites were selected based on those predominant in vivo in human metabolites .…”

Metabolite Generation via Microbial Biotransformations with Actinomycetes: Rapid Screening for Active Strains and Biosynthesis of Important Human Metabolites of Two Development-Stage Compounds, 5-[(5S,9R)-9-(4-Cyanophenyl)-3-(3,5-dichlorophenyl)-1-methyl-2,4-dioxo-1,3,7-triazaspiro[4.4]non7-yl-methyl]-3-thiophenecarboxylic Acid (BMS-587101) and Dasatinib

“…Much of the work in microbial models of mammalian metabolism has focused on finding one or a limited number of "super" strains capable of producing most of the mammalian metabolites of a given drug or drug candidate, so that the majority of the metabolites of interest can be obtained with a minimal number of incubations (Cannell, 1995;Joanna, 1999;Zhang et al, 2006;Zmijewski et al, 2006). Alternatively, for the purpose of preparing specific key mammalian metabolites, it may be advantageous to have an array of microbial strains with differing selectivities for the separate production of individual metabolites.…”

“…Work in this area has been reviewed (Abourashed et al, 1999;Azerad, 1999), and there has been an increasing number of reports describing the use of microbial systems to mimic or predict mammalian metabolite formation and to prepare larger quantities of mammalian metabolites (Moody et al, 1999(Moody et al, , 2002Xie et al, 2005;Zhang et al, 2006;Zmijewski et al, 2006). The traditional microbial screening methods using shake flasks are labor intensive, which has likely limited the widespread use of microbial biotransformation in drug metabolism studies.…”