Acetyl conjugation

When channel catfish were intravascularly dosed with radiolabeled acriflavine or proflavine, total residue equivalent concentrations were highest in the excretory organs and lowest in muscle, fat, and plasma (84). In proflavine-dosed fish, residues in liver and trunk kidney were composed primarily of glucuronosyl and acetyl conjugates of proflavine residues in muscle were composed mostly of the parent drug. In acriflavine-dosed fish, the parent compound made up 90% of the total residues in all tissues examined. 

Type I reactions include the formation of glycosylated, sulfated, methylated, and acetylated conjugates, whereas type II reactions include peptide and glutathione conjugation. 

Figure 2.30. Metabolism of isoniazid. a Acetylation, b Hydrolysis of the acetyl conjugate leads to liver toxicity, c Distribution of acetylation rates in the population.

Disposition in the Body. Rapidly absorbed after oral administration. About 65 to 71% of a dose is excreted in the urine, mainly as unchanged drug, the V -acetyl conjugate, and sulphanilamide. 

It appears that glucoside isoflavones and their malonyl and acetyl conjugates are hydrolyzed by intestinal bacteria to aglycones prior to being absorbed. However, not everyone has the same intestinal microflora ability to hydrolyze the glucosides. A study (Xu et al., 1995) shows that two of six women studied were not able to hydrolyze the glucosides. Therefore, it is important to analyze the individual forms of isoflavones instead of total isoflavones in the foods, because foods vary widely in aglycone contents. 

A-acetyl transferases Amino acid conjugation Cytosohc Mitochondria, microsomal Acetylation Conjugation Acetyl-coenzyme A Acyl-CoA, serine, proline 2 [120]... 

The O-acetyl-conjugates were encountered only infrequently in plants, they were detected as O-acetyl-ZRMP and O-acetyl-DHZRMP in Lupinus angustifolius after... 

Acetylated conjugates. Phase I Biotransformation products that contain amino, hydroxyl, or sulfur groups may be acetylated, producing conjugates that can be excreted in the urine. An example of a Phase I product that would be acetylated is p-aminobenzoic acid, producing p-(N-acetamido)benzoic acid. 

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