The in vitro metabolism and in vivo pharmacokinetics of the bacterial β-glucuronidase inhibitor UNC10201652

Figures & data

Table 1. Summary of metabolites of UNC10201652 detected in microsome and hepatocyte stability assay samples.

Proposed assignment		Microsomes			Hepatocytes
		Human	Rat	Mouse	Human	Rat	Mouse
Parent	Parent	✓	✓	✓	✓	✓	✓
M1	Oxidation – C4H7NO	✗	✗	✓	✗	✗	✓
M2	Parent – 2× C2H2	✗	✗	✗	✗	✓	✗
M3	3× Oxidation – C4H7NO	✗	✗	✗	✗	✗	✓
M4	Parent – C2H2	✗	✓	✗	✗	✓	✗
M5	Parent – C2H2	✓	✓	✓	✓	✓	✓
M6	Oxidation – C2H2	✗	✗	✗	✗	✓	✓
M7	Desaturation	✗	✗	✗	✓	✗	✗
M8	Reduction + desaturation	✗	✗	✗	✓	✗	✗
M9	Oxidation + desaturation – C2H2 + methylation	✗	✗	✗	✗	✓	✓
M10	2× Oxidation × C2H2	✗	✗	✗	✗	✗	✓
M11	Oxidation + desaturation	✗	✗	✗	✓	✗	✗
M12	Oxidation	✗	✗	✓	✗	✓	✓
M13	Oxidation	✗	✓	✓	✗	✓	✓
M14	Oxidation	✗	✗	✗	✗	✗	✓
M15	Oxidation	✓	✓	✗	✓	✓	✗
M16	Hydration	✗	✗	✗	✗	✓	✗
M17	Hydration	✗	✗	✗	✗	✗	✓
M18	Oxidation + desaturation + methylation	✗	✗	✗	✓	✗	✗
M19	2× Oxidation	✗	✗	✗	✗	✓	✓
M20	Oxidation + hydration	✗	✗	✗	✗	✓	✗
M21	Glucuronidation	✗	✗	✗	✓	✗	✗
M22	Oxidation + glucuronidation	✗	✗	✗	✓	✗	✗
M23	Oxidation + glucuronidation	✗	✗	✗	✓	✗	✗
M24	Oxidation + glucuronidation	✗	✗	✗	✓	✗	✗

Table 2. Pharmacokinetic parameters for UNC10201652 following IV and PO Administration to mice (3 mg/kg) with and without ABT pre-treatment.

Route	Tmax (h)	^aCmax (ng/mL)	AUClast (h*ng/mL)	AUCINF (h*ng/mL)	T1/2 (h)	CL (mL/min/kg)	Vss (L/kg)	F b (%)
IV	–	240.6	137.4	154.0	0.66	325.0	16.7	–
IV + ABT	–	240.2	315.9	392.4	3.66	127.4	33.9
PO	0.25	15.2	20.1	NR	–	–	–	15^c
PO + ABT	1.0	184.0	252.8	NR	–	–	–	184

^aBack extrapolated concentrations for iv dosing.

^bAUC last considered for calculating bioavailability ^c bioavailability calculated with control group.

Figure 1. The structure of the specific GUS inhibitor UNC10201652 (4-(8-(piperazin-1-yl)-1,2,3,4-tetrahydro-[1,2,3]triazino[4',5':4,5]thieno[2,3-c]isoquinolin-5-yl)morpholine (Inh 9).

Figure 2. Proposed structures of metabolites of UNC10201652 detected in hepatocyte stability and microsomal stability assay samples. As glucuronidation usually occurs on nucleophilic functional groups these have been shown with Markush structures on the metabolite as possible sites of conjugation. Structure elucidation was not performed on metabolites M7 and M17 as no suitable MSMS data were obtained.

Figure 3. Summed XIC’s of all the metabolites of UNC10201652. Upper: 120 min human hepatocyte samples. Middle: 20 min mouse, and lower: 20 min rat. Metabolites M7 and 18 are not shown in these mass chromatograms. Other peaks are considered to arise from endogenous material.

Figure 4. Upper: IV and lower: PO plasma profiles for UNC10201652 following administration at 3 mg/kg in dose vehicle (squares) or following ABT pre-treatment (triangles).