7-methoxyresorufin

Liver contained 156 (68-563) pg PCB 126/kg FW pronounced liver enlargement lymphoid depletion of spleen 10-fold increase in hepatic microsomal EROD and benzyoxyresorufin-O-dealkylase 5-fold increase in methoxyresorufin-O-dealkylase Liver had 380 pg PCB 126/kg FW with increasing necrosis above effects plus decreased bone growth, decreased spleen weight, and degenerative lesions of thyroid Liver had 1.1 (0.6-4.5) mg PCB 126/kg FW above effects plus decreased body weight, decreased hepatic thiol concentrations, and increased plasma enzyme activities... 

Flavonoids, especially flavones and flavonols, also directly bind to several CYP isoforms (lAl, 1A2, IBl, 3A4) involved in xenobiotics metabolism and inhibit enzyme activity. Structure-activity relationships show rather high isoform selectivities depending on the flavonoid substitution pattern and contrasted inhibition mechanisms. For instance, inhibition by flavonoids of 7-methoxyresorufin O-demethylation in microsomes enriched in CYP lAl and 1A2 reveals that galangin (3,5,7-trihydroxyflavone) is a mixed inhibitor of CYP 1A2 (.ST = 8 nM) and a five times less potent inhibitor of CYP 1A1. By contrast, 7-hydroxy flavone is a competitive inhibitor of CYP lAl (Aii = 15 nM) and a six times less potent inhibitor of CYP 1A2. In addition, fairly selective inhibition of CYP IBl (specifically detected in cancer cells) by some flavonoids has been reported. For example, 5,7-dihydroxy-4 -methoxyflavone inhibits IBl, 1 Al, and 1A2 with IC50 values of 7, 80, and 80 nM, respectively. ... 

E163K/V193M/167Q Directed evolution 7-Methoxyresorufin [153]... 

A2 Phenacetin, theophylline, acetaminophen, warfarin, caffeine, cimetidine Aromatic amines, arylhydrocarbons, NNK,3 aflatoxin, estradiol Caffeine, [acetanilide, methoxyresorufin, ethoxyresorufin]... 

Kim D, Guengerich FP. Enhancement of 7-methoxyresorufin O-demethylation activity of human cytochrome P450 1A2 by molecular breeding. Arch Biochem Biophys 2004 432 102-8. 

As exemplified by the 0-deethylation of ethoxyresorafin, and by either the 0-demethyIation of methoxyresorufin or the metabolic activation of Glu-P-1 to mutagens in the Ames test. In all cases Western Blot analysis supported the enzymic studies. All activities were expressed in terms of total cytochrome P450 concentraticHi. 

A12,9A14 Helicoverpa armigera p-nitroanisole, methoxyresorufin, esfenvalerate [285]... 

The ability of human CYP1A2 to catalyze O-demethylation of 7-methoxyresorufin was improved by three rounds of mutagenesis. The triple-mutant E163K/V193M/ K170Q exhibited turnover rates more than five times faster than wild-type CYP1A2 [146]. 

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