Biotransformation of coumarin derivatives (2). Oxidative metabolism of 7-alkoxycoumarin by microsomal enzymes and a simple assay procedure for 7-alkoxycoumarin O-dealkylase.

Abstract

The in vitro biotransformation of 7-alkoxycoumarin by rat liver microsomes was studied to develop a simple and accurate assay procedure for 7-alkoxycoumarin

Sex and circadian modulatory effects on rat liver as assessed by transcriptome analyses

“…The 7-methoxycoumarin, 7-ethoxycoumarin, and 7-hydroxycoumarin were purchased from Aldrich. The 7-propoxycoumarin was synthesized as previously described (Matsubara et al, 1983). Using these substrates, the 7-alkoxycoumarin O-dealkylase (ACD) activities [7-methoxycoumarin O-dealkylase (MCD), 7-ethoxycoumarin Odealkylase (ECD), and 7-propoxycoumarin O-dealkylase (PCD) activities] were measured in the microsomal fractions by the method of Matsubara et al (1983).…”

“…The 7-propoxycoumarin was synthesized as previously described (Matsubara et al, 1983). Using these substrates, the 7-alkoxycoumarin O-dealkylase (ACD) activities [7-methoxycoumarin O-dealkylase (MCD), 7-ethoxycoumarin Odealkylase (ECD), and 7-propoxycoumarin O-dealkylase (PCD) activities] were measured in the microsomal fractions by the method of Matsubara et al (1983). The P450 content and protein concentrations in the microsomal fractions were determined by the methods of Omura and Sato (1964) and Lowry et al (1951), respectively.…”

Cytochrome P-450-Dependent Monooxygenase Activities in Prenatal and Postnatal Human Livers: Comparison of Human Liver 7-Alkoxycoumarin O-Dealkylases with Rat Liver Enzymes

“…The resulting filtrate was used for the assay. Liver microsomes were prepared as described previously (19). Determination of drug -metabolizing activity and cytochromes 7-Alkoxycoumarin 0-dealkylase activity in both liver microsomes and homogenates was determined as described previously (19).…”

“…we examined the developmental and senile changes of cytochrome P-450 dependent drug -metabolizing activities in human livers at various prenatal and postnatal stages by employing the 7-alkoxycoumarin 0-dealkylation reaction (19) as a model and compared this data with the corresponding animal obtained using rat liver samples.…”

Effects of MCPA and Other Phenoxyacid Compounds on Hepatic Xenobiotic Metabolism in Rats.

“…The activity of aminopyrine N-demethylase was determined by the formation of HCHO after the addition of Nash's reagent (Nash 1953). The activity of 7-ethoxycoumarin 0-deethylase was measured by monitoring the fluorescence of 7-hydroxycoumarin formed (Matsubara et al 1983). The activity of UDP-glucuronyltransferase was measured by monitoring for the reduction of p-nitrophenol (Isselbacher et al 1962).…”