S-Glucuronides

Topical retinoids—tretinoin, adapalene, tazarotene, and in some countries topical isotretinoin, motretinide, retinaldehyde, and retinoyl-/S-glucuronide —should be used as first-line therapy for mild to moderate inflammatory acne and comedonal acne. They are also preferred agents for maintenance therapy to minimize antibiotic use in acne therapy. To optimize efficacy in moderate inflammatory acne, topical retinoids should be combined with topical antibiotics or BP0.2T33... 

Other catabolic products include sulfenic acids (R-SOH), S-glucuronides, S-methylconjugates, cyste-ine-S-conjugates, and more. 

Some S-glucuronides are formed from aliphatic thiols, aromatic thiols and dithiocarboxylic acids. As for C-glucuronidation, this reaction is seen in humans for 1,3-dicarbonyl drugs, such as sulfinpyrazone. 

A number of substances in this group contain a thiol group, which is predicted to be metabolized by methylation followed by oxidation, conjugation with GSH, S-glucuronidation and/or oxidation to sulfonic acids. These would be the major routes... 

The use of urine has been advocated as best sample for doping controls, in part due to the relative easiness of collection and in part because of the higher levels found in urine over blood. Most doping agents, especially steroids, are excreted with their hydroxyl function being substituted with either S-glucuronide or sulfate. Measurements of doping compounds excreted in urine are currently performed either as the... 

A. Glucuronidation UDP-glucuronyltransferases (EC 2.4.1.17) The reaction may occur spontaneously with some substrates Phenols, alcohols carboxylic acids amines, amides, sulphonamides, thiols RXH + uridinediphospho-j8-D-glucuronic acid RX-glucoronide + uridine-5 -diphosphate where X is O, N or S (and more rarely C) to give 0-, N- and S-glucuronides. 

UDP-glucuronic acid can be transferred to cortisol to form an ether 0-glucuronide bilirubin to form an ester 0-glucuronide aniline to form an amide A-glucuronide mercaptobenzothiazole to form a thioether S-glucuronide. 

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