P-450 oxygenases

In vitro exposure of chicken trachea cells to 2,3-benzofuran results in substantial inhibition of ciliary activity (Pettersson et al. 1982), which may indicate that ciliotoxicity is involved in the respiratory effects seen in mice. Certain other furan derivatives exhibit pulmonary toxicity due to metabolic activation by lung P-450 oxygenases (Boyd 1981), but 2,3-benzofuran... 

Pretreatment of male mice with compounds that affect cytochrome P-450 oxygenases altered the toxicity of a single intraperitoneal injection of... 

These superoxo complexes are relevant models for the naturally occurring oxygen carriers hemoglobin and myoglobin, which contain ferroprotoporphyrin IX as an active center in which the sixth axial postion is occupied by the imidazole moiety of histidine.17 They also intervene as primary oxygen adducts in enzymatic cytochrome P-450 oxygenases.18... 

An axenic poplar cell culture experiment exhibited conclusively that poplar cells are capable of transforming and mineralizing TCE without the involvement of microbial metabolism. The metabolites of TCE in cell cultures include trichloroethanol, trichloroacetic acid, and dichloroacetic acid, which was the most predominant. Chloral hydrate was also found at levels lower than the detection limit and is a product of TCE oxidation by cytochrome P-450 oxygenase and the precursor of trichloroethanol and trichloroacetic acid in mammalian systems. The same metabolites were identified in field sites where vegetation was exposed to TCE contaminated groundwater and in laboratory studies. ... 

The first two carbinolamlnes named were synthesized using sequential catalysis by cytochrome P-450 oxygenase and glucuronyl transferase inmobllized from rabbit liver microsomes onto sepharose beads (64,65) as shown in scheme 3. 2-Pra1 idoxime chloride was allowed to decompose at pH 7.4 in the presence of immobilized UDP-glucuronyl transferase and the cofactor uridine... 

Not all oxidations of alkaloids can be ascribed to microsomal P-450 systems. Mammalian liver contains a flavoprotein oxidase, first discovered in rabit liver and called quinine oxidase . It is also an aldehyde oxidase, and its mechanism of action on heterocyclic nitrogen compounds probably involves addition of hydroxide ion to a suitable ring position, followed by dehydrogenation. Thus, the introduced oxygen atom comes from water rather than from molecular oxygen, in contrast to the P-450 oxygenases. [2]. 

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