Metabolic conjugates

For N-methyl arylamines, electrophilic N-sulfonyloxy esters appear to be strong candidates for the ultimate carcinogenic metabolites. However, additional studies are required as these conclusions are circumstantially based on their comparative reactivity with nucleophiles and on the failure of other metabolic conjugation systems to esterify N-hydroxy-N-methyl arylamines (9,187). 

Jakokby, W.B. (1981). Detoxification and drug metabolism conjugation and related systems. In Methods in Enzymology, Vol. 77. Academic Press, New York... 

M18. Millbum, P., Factors in the biliary excretion of organic compounds. In Metabolic Conjugation and Metabolic Hydrolysis (W. H. Fishman, ed.), Vol. 2, pp. 1-74. Academic Press, New York, 1970. 

Hydrolysis of metabolic conjugates with HCl, extraction on CIS cartridges, desorption... 

There are, however, some particular conditions which point to a drug or chemical causation. Hepatitis is one such condition, and it can easily be seen that the liver can be a target because of its part in the metabolism, conjugation and excretion of chemicals. The kidney seems to be at much less risk as an excretory organ alone, nevertheless renal damage by drugs is more common than heart or lungs, for example. 

Urinary excretion of quercetin increased significantly with dose and time after the consumption of fruit juice (blackcurrant and apple juice in a 1 1 mixture) in humans [75]. Ranges from 0.29-0.47% of ingested quercetin were found in the urine. The presence of quercetin in urine shows that it was absorbed by the gut, but the urinary content does not necessarily reflect absolute absorptive efficiency because absorbed quercetin may be metabolized (conjugated), stored and excreted through other routes such as the biliary tract. However, since quercetin is present in a variety of fruit and vegetables, plasma concentrations or urinary excretion of quercetin may potentially be useful as biomarkers of habitual intake of these foods. 

Schachter, H. Rosen, L., Eds. "Metabolic Conjugation and Metabolic Hydrolysis" Academic Press New York, 1973 p. 1. 

PHASE II METABOLISM Conjugations, most commonly with glucuronide, sulfate, or glutathione. 

Some metabolic conjugative processes result in the production of lipophilic derivatives that are not readily eliminated. While their physical properties are different from the classical hydrophilic conjugates, the mechanism of formation clearly defines them as conjugates (i.e., they are formed as the result of a union of xenobiotic metabolites with endogenous molecules). The reactions involve the coupling of xenobiotic acids and alcohols with endogenous intermediates of lipid synthesis (i. e., the acids with glycerol and cholesterol and the alcohols with the fatty acids). 

Mudd, S.H., 1973. Biochemical mechanisms of methyl trarrsfer. Metabol. Conjugation Metabol. Hydro ., 3 297-350. 

The.se arc relatively nontoxic, metabolically conjugated (as glucuronides). and rapidly excreted. 

Anion Exchange Thermospray Tandem Mass Spectrometry of Polar Urinary Metabolites and Metabolic Conjugates... 

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