Oxidations and reductions of alcohols aldehydes and ketones

Alcohol dehydrogenases (aryl-alcohol dehydrogenase E.C. 1.1.1.90, aryl-alcohol dehydrogenase (NADPH) E.C. 1.1.1.91) Human brain enzyme is composed of at least five isozymes, pI 5.3, 6.0, 6.3, 7.0 and 7.9. They all act on p -nitrobenzaldehyde and indole-3-acetaldehyde, but are distinguished by their relative activities towards menadione, daunorubicin, p -hydroxyphenylacetaldehyde and p -hydroxymandelaldehyde as potential substrates. All require NADPH one that can also utilize NADH appears to be...

Reduction of nitro compounds to anilines

The active enzymes are haemoglobin or methae-moglobin. Studies with pure proteins found that the reaction can be catalyzed by haem-containing proteins such as methaemoglobin, metmyoglobin and cytochrome c, with NADPH as reducing agent. Placental reduction and the haem-model system (haematin, NADPH, FMN and p -nitrobenzoate) are inhibited by carbon monoxide A621 . Formation of p -aminobenzoate from p -nitrobenzoate is observed in conventional rats, but is, relatively, very low in germ-free...

Rcocooh 0 Rcho

Pseudomonas putida decarboxylates p -hydroxyphenylglyoxylate to form p -hydroxybenzaldehyde E669 . The enzyme requires thiamine pyrophosphate with phenylglyoxylate, p -methylphenylglyoxylate, p -chloromethylphenylglyoxylate and p -fluoromethylphenylglyoxylate as substrates. p -Bromomethylphenylglyoxylate is inhibitory it reacts with the cofactor to yield bromide and (p -methylbenzoyl)thiamine pyrophosphate which in turn forms p-toluate. A small proportion of p -chloromethylphenylglyoxylate...

Demethylation of Nmethylated amides

Results, combined with the effects of selective inhibitors indicate that most of the dealkylation occurs directly, rather than via the N-oxide A310 . Ethylmorphine N-demethylase is found in quokka, kangaroo, bettong, bandicoot, and possum (marsupials), as well as in rat A2420 . Activity of rat and mouse liver enzymes is increased by EDTA and decreased by Fe2 + this probably correlates with inactivation by lipid peroxides A89 . Imipramine demethylase activity found in rat hepatocyte microsomes...

Tyrosinase and unspecified types

Apple enzyme is composed of isozymes, molecular weights 46000, 120000, 460 000 and 800000. They are considered to be polymers of a common monomer A1133 . Amasya apple enzyme contains three isozymes, with optima at pH 6.6 9.0, dependent on the substrate substrates are catechol, 4-methylcatechol, pyrogallol and l-dopa H567 . Four Arachis peroxidase isozymes, which additionally exhibit polyphenol oxidase activity towards l-dopa, have optima at pH 7.6, 8.0, 8.0 and 8.0 A2519 . Artichoke enzyme,...

Formation and degradation of sidechains

Human bone marrow supplemented with S-adenosylmethionine converts benzene into toluene, which in turn yields o -, m - and p -xylenes F853 . This may account for the apparent hydroxymethylation of benzene (Sloane, N.H., Biochim. Biophys. Acta (1965), 107, 599 Sloane, N.H., Heinemann, M., Biochim. Biophys. Acta (1970), 201, 384). Rat is able to incorporate a methyl group at positions 7 and 12 of benzanthracene and possibly its metabolites. Incorporation was not observed with a range of...

Cyclopropane ring fission

Rat liver microsomes act on 1,1-dichloro-cis -diphenylcyclopropane to form several products such as 2-chloro-3-oxo-1,3-diphenyl-1-propene. This involves an unusual type of ring fission which is considered to form 2,3-dichloro-1,3-diphenyl-1-propene as the initial product F573 . Methylococcus capsulatus soluble methane monooxygenase (E.C. 1.14.13.25) converts cyclopropylbenzene into benzyl alcohol. 3-Phenylprop-2-en-1-ol is also formed, and this may be an intermediate F278 . 1.6 Reactions...

Hydroxyphenylpyruvate reductase E C 111237

Coleus blumei enzyme, which requires NADH reduces p -hydroxyphenylpyruvate and 3,4-dihydroxyphenylpyruvate to the corresponding lactates E660 . Aromatic a-ketoacid reductase ((R)-aromatic lactate dehydrogenase 1.1.1.222, diiodophenylpyruvate reductase E.C. 1.1.1.96) Dog heart enzyme is a cytosolic dimer, monomeric molecular weight 40000, pI 5.4, which requires NADH. Activity is also found in brain, kidney and liver, and is considered to be associated with an isozyme of malate dehydrogenase. The...