TY - JOUR T1 - 4-Nitrocatechol production from rho-nitrophenol by rat liver. JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 631 LP - 638 VL - 193 IS - 2 AU - J Chrastil AU - J T Wilson Y1 - 1975/05/01 UR - http://jpet.aspetjournals.org/content/193/2/631.abstract N2 - Time course studies of rho-nitroanisole O-demethylation revealed formaldehyde production in excess of rho-nitrophenol (PNP) and 4-nitrocatechol (NTC) formation by rat liver microsomes. This indicated that these products (PNP, NTC) were metabolised further. The hydroxylation reaction PNP yields NTC showed substrate and product inhibition and a requirement for reduced nicotinamide adenine dinucleotide phosphate and O2 and was localized in liver microsomes. It was strongly activated by ascorbic acid, cysteine, adenosine triphosphate or hydroxylamine in vitro and enhanced by phenobarbital treatment in vivo. Mercapturic derivatives were metabolized to the corresponding hydroxy compounds with the same speed as their parent compounds. Both PNP and NTC were metabolized to the corresponding glucuronide and sulfate conjugates. On the other hand, the PNP or NTC glucuronides and sulfates were metabolized with liver microsomes to PNP and NTC. ER -