An intermediate
in the phase II reaction that results in the formation of glucuro_x0002_nic acid conjugates of xenobiotics which contain substituents
such as hydroxyl, amino, or sulfhydryl groups, forming the O-,
N-, and S-glucuronides, respectively. UDPGA is formed by
two reactions: (i) the formation of UDPG from UTP and glucose 1-phosphate and (ii) the formation of UDPGA from
UDPG. The two reactions are catalyzed by UDPG pyrophosphorylase and UDPG dehydrogenase, respectively, whereas
glucuronide formation is catalyzed by glucuronosyltransferase.
Glucuronide formation from xenobiotics is common in all animal groups except insects.