TABLE 1

Mass spectrometric characterization of veliparib and its metabolites in plasma, bile, or urine from rats and dogs

Identification	[M + H⁺]	Proposed Formula	Fragment Ions (m/z)	Biotransformation	Matrix
Veliparib	245	C₁₃H₁₆N₄O	MS²: 84, 145, 162		Bile, urine, plasma (R, D)
M1	261	C₁₃H₁₆N₄O₂	MS²: 100, 162, 216	Monooxidation	Urine (R, D), plasma (D)
M2	261	C₁₃H₁₆N₄O₂	MS²: 84, 178, 216	Monooxidation	Urine, plasma (R, D)
M3	277	C₁₃H₁₆N₄O₃	MS²: 162, 259 MS³ of m/z 259: 98, 145, 162, 242	Pyrrolidine ring-opening	Bile, urine, plasma (R, D)
M4	277	C₁₃H₁₆N₄O₃	MS²: 162, 202, 232, 249, 259, 260	Dioxidation or pyrrolidine ring-opening	Bile, urine, plasma (R, D)
M5	437	C₁₉H₂₄N₄O₈	MS²: 161, 178, 261, 337, 354	Oxidation + glucuronidation	Bile (R, D), plasma (D)
M6	437	C₁₉H₂₄N₄O₈	MS²: 145, 162, 209, 226,	Oxidation + glucuronidation	Bile (R)
M7	259	C₁₃H₁₄N₄O₂	MS²: 98, 145, 162, 197, 214, 224, 242	Oxidation + dehydrogenation	Bile, urine, plasma (R, D)
M8	259	C₁₃H₁₄N₄O₂	MS²: 98, 162, 242	Lactam formation	Bile, urine, plasma (R, D)
M9	465	C₂₀H₂₄N₄O₉	MS²: 145, 162, 245, 289	Carbamoyl glucuronidation	Bile, plasma (R, D)
M10	451	C₁₉H₂₂N₄O₉	MS²: 145, 162, 258, 275	M8 + oxidation + glucuronidation	Bile (R)
M11	451	C₁₉H₂₂N₄O₉	MS²: 161, 178, 258, 275, 434	M8 + oxidation + glucuronidation	Bile (R, D)