Uridine diphosphate glucuronide transferase

Scheme 1.6 Uridine diphosphate glucuronide transferase cycle. (Reproduced by permission of the Royal Society of Chemistry.)...

UGT lAl uridine diphosphate glucuronosyl transferase lAl TPMT thiopurine methyl transferase SN-38 an active metabolite of ironotecan SN-38G a glucuronide metabolite of SN-38. 

O-glucuronidation is catalysed by glucuronyl transferase that transfers a glucuronic acid moiety from uridine diphosphate glucuronide to an alcohol, phenol or carboxylic acid group (Fig. 8.36). This is the most important... 

Figure 8.36 Glucuronidation of a hydroxylated compound by UDP-glucuronyl transferase with uridine diphosphate glucuronide (UDPG) as the co-factor.

The other primary Phase II metabolic pathway is glucuronidation, which involves the formation ofglucuronic acid conjugates of xenobiotics. This is catalyzed by a family of UDP-glucuronosyl transferases (UGTs) in the presence of uridine diphosphate... 

It has now been established that in common with many other glu-curonides, bilirubin glucuronide can be synthesized in the adult rat, rabbit, mouse, and guinea pig liver by the enzymatic transfer of glucuronic acid from uridine diphosphate glucuronic acid to an acceptor substance, namely, bilirubin (Fig. 3) (B17, G5, L3, L5, S8). The transferring enzyme (glucuronyl transferase) has been shown by Schmid et al. 

Polycyclic aromatic amines are readily absorbed into the body via the gastrointestinal tract, where metabolic activation takes place. Aryl amines are N-hydroxylated and subsequently glucuronidated via uridine diphosphate (UDP)-glucuronosyl transferase or sulfated by sulfotransferases, N-acetylation of the amine, and 0-acetylation of the N-hydroxy amine can occur. 

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