. 2021 Feb;49(2):133–141. doi: 10.1124/dmd.120.000254

TABLE 2.

Fractional bioactivation and computational scores for each observed meclofenamate metabolite and corresponding adduct

Analyte	Model Score^a	Depletion V_max/K_m	Bioactivation V_max/K_m or K_h	F_ba^b	Bioactivation (%)
Dechloro-ortho-quinone-imine	0.26		3.8 (3.1–4.6)	0.053 (0.031–0.090)	5.3 (3.1–9.0)
Monohydroxy para-quinone-imine	0.67/0.92^c		5.0 (3.4–7.5)	0.070 (0.034–0.147)	7.0(3.4–14.7)
Dihydroxy ortho-quinone	0.42/0.45^c		0.12 (0.08–0.19)	0.002 (0.001–0.004)	0.2 (0.1–0.4)
Multi-GSH adduct	NP^d		0.18 (0.12–0.27)	0.003 (0.001–0.005)	0.3 (0.1–0.5)
Total		71.1 (51.0–99.2)	9.1 (6.7–12.6)	0.128 (0.067–0.246)	12.8 (6.7–24.6)

^{^a}

Model scores reflect the relative likelihood for metabolite formation after metabolism of the parent drug, meclofenamate. Scores range from 0.0 to 1.0, with higher scores indicating a greater likelihood for formation of the specific metabolite structure.

^{^b}

Fractional bioactivation (F_ba) is defined as a fraction of metabolic bioactivation catalytic efficiency and metabolic depletion catalytic efficiency.

^{^c}

Multiple bioactivation scores reflect different possible reactive metabolite isomers whose structures could not be definitively attributed to the observed metabolite based on mass spectrometry.

^{^d}

No prediction (NP) for putative metabolite and adduct because of the inability to characterize its structure by mass spectrometry.