TABLE 6

Fragmentation patterns of KAE609 and metabolites

Structural characterization of metabolites was carried out by LC-MS/MS analysis. The proposed structures of the metabolites were based on their elemental composition derived from accurate mass measurements and fragment ions in their data-dependent MS² and MS³ mass spectra. Comparison of metabolite fragment ions with those of KAE609 allowed the assignment of regions of biotransformation, as presented in Figure 5.

Compound	[MH⁺] m/z	Elemental Formula	Diagnostic Fragment Ions
KAE609	390.0573	C₁₉H₁₅Cl₂FN₃O	390, 347,^{^b} 319,^{^b} 312, 284, 276
M14	404.0362	C₁₉H₁₃Cl₂FN₃O₂	404, 386,^{^b} 360, 351, 325, 278
M16	420.0322	C₁₉H₁₃Cl₂FN₃O₃	420, 402,^{^b} 376, 367, 341
M18	388.0416	C₁₉H₁₃Cl₂FN₃O	388, 359,^{^b} 324
M20.8	410.046	C₁₈H₁₅Cl₂FN₃O₃	410, 392, 349, 226,^{^b} 184
M21.8	420.0302	C₁₉H₁₃Cl₂FN₃O₃	420, 402, 379,^{^b} 362,^{^b} 337, 252
M23	404.0363	C₁₉H₁₃Cl₂FN₃O₂	404, 375,^{^b} 340, 235
M23.5A	420.0324	C₁₉H₁₃Cl₂FN₃O₃	420, 391,^{^b} 356, 328
M23.5B	434.048	C₂₀H₁₅Cl₂FN₃O₃	434, 419,^{^b} 405
M24	404.0362	C₁₉H₁₃Cl₂FN₃O₂	404, 375,^{^b} 340, 235
M29.8	406.0524	C₁₉H₁₅Cl₂FN₃O₂	406, 210^{^b}
M32	404.0375	C₁₉H₁₃Cl₂FN₃O₂	404,^{^b} 386
M34	406.0528	C₁₉H₁₅Cl₂FN₃O₂	406, 391, 210,^{^b} 182, 175
M35	402.0216	C₁₉H₁₁Cl₂FN₃O₂	402, 374, 367,^{^b} 346, 338, 323^{^b}
M35.8	562.0595	C₂₅H₁₉Cl₂FN₃O₇	562, 386^{^b}
M37^{^a}	392.0574	¹⁴CC₁₈H₁₅Cl₂FN₃O	392, 327, 279, 210,^{^b} 175^{^b}
M40	388.0419	C₁₉H₁₃Cl₂FN₃O	388,^{^b} 359, 210
M48	386.0256	C₁₉H₁₁Cl₂FN₃O	386,^b 351

↵^a The molecular ion of M37 was previously detected in human hepatocyte after incubated with [¹⁴C]KAE609.
↵^b Indicates the most abundant fragment ions.