TABLE 4

Diagnostic MS product ions used for tofacitinib and proposed metabolite structures

IDStructure and MS/MS Product IonsIon m/zDiagnostic MRM Fragment Ions
TofacitinibEmbedded Image313MS2: 149, 165, 173, 229, 246, 272
M1Embedded Image299MS2: 135, 165, 215, 232
M2Embedded Image304MS2: 149, 156, 173, 229, 246, 256, 274
M4Embedded Image318MS2/MS3: 149, 173, 182, 229, 231, 246, 274
M8Embedded Image329MS2: 165, 189, 245, 262, 288
M9Embedded Image329MS2: 165, 189, 245, 262, 288, 301
M11Embedded Image345MS2: 165, 181, 278, 317
M14Embedded Image345MS2: 149, 197, 260, 278, 327
M18Embedded Image329MS2: 149, 177, 244, 280, 294, 311
M20Embedded Image489MS2: 149, 165, 313
MS3: 149, 165, 173, 229, 246, 272
M22Embedded Image343MS2: 165, 179, 248, 315
M29Embedded Image480MS2: 304
MS3: 149, 156, 173, 229, 246, 256, 274
M31Embedded Image320MS2: 156, 165, 190, 245, 262, 272, 290, 292

  • MRM, multiple reaction monitoring.