OH OH/
 o P P O

'OHH

 UDPGA


PAPS


PAP


SULT (cytosol)





~UG T (ER)


sulfonate conjugate






\ 0,0




 Cl OH


xenobiotic


UDP


 glucuronide conjugate



Figure 2-1. Structure of the co-substrates PAPS and UDPGA (transferred moieties shown
 in bold) and the formation of the polar sulfonate and glucuronide conjugates,
 shown here competing for the same substrate.