Sulfate conjugation mammals

The concept of microbial models of mammalian metabolism was elaborated by Smith and Rosazza for just such a purpose (27-32). In principle, this concept recognizes the fact that microorganisms catalyze the same types of metabolic reactions as do mammals (32), and they accomplish these by using essentially the same type of enzymes (29). Useful biotransformation reactions common to microbial and mammalian systems include all of the known Phase I and Phase II metabolic reactions implied, including aromatic hydroxylation (accompanied by the NIH shift), N- and O-dealkylations, and glucuronide and sulfate conjugations of phenol to name but a few (27-34). All of these reactions have value in studies with the alkaloids. 

Although sulfate conjugation Is widely distributed amongst mammals, the pig has a deficiency In the sulfation of certain phenols (42). 

Four principal metabolites have been identified in mammals two phenol and two hydroquinone conjugates (of sulfate and glucuronide) (Capel et al. 1972 Kenyon et al. 1995 Wheldrake et al. 1978). 

Although mammals all metabolize phenol to the same metabolites, the amounts of each metabolite vary between species. For example, in the old world monkeys and prosimians, sulfation is the major phenol conjugation pathway, while in the new world monkeys, glucuronidation predominates (Mehta et al. 

Figure 14- Hidden conjugates of quercetin, a naturally-occurring mutagen, are the glucuronide and sulfate derivative of isorhamnetin. These products are not present in the excreta of mammals but are biliary metabolites.

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