Human UDP-glucuronosyltransferase UGT1A4 forms tertiary N-glucuronides predominately with the energetically less favored tautomer of substituted 1H-indazole (benzpyrazole)

Journal of Analytical Science and Technology

Table 2 Percentage of glucuronide formation with recombinant human UDP-glucuronosyltransferases in supersomes^TM after 4 h (DAD at 240 nm)

rh UDP-glucuronosyl-transferase	2	3	Selectivity factor for 3 vs. 2
1A1	<0.2%	<0.2%	n.m.^a
1A3	<0.2%	0.7%	>4
1A4	1.4%	47.4%	33
1A6	<0.2%	0.3%	>2
1A7	<0.2%	<0.2%	n.m.
1A8	<0.2%	<0.2%	n.m.
1A9	<0.2%	<0.2%	n.m.
1A10	<0.2%	<0.2%	n.m.
2B4	<0.2%	<0.2%	n.m.
2B7	<0.2%	<0.2%	n.m.
2B10	<0.2%	<0.2%	n.m.
2B15	<0.2%	<0.2%	n.m.
2B17	<0.2%	<0.2%	n.m.