TABLE 1

Kinetic data for the two main metabolic steps of (R,S-)MDEA

Units used are as follows: Vmax, picomoles per minute per picomole; and Km, micromolar.

MDA Formation
DHEA Formation
Vmax
Km
Vmax/Km
Vmax
Km
Vmax/Km
R,S-MDEA CYP1A2 19 ± 0.6 91 ± 11 0.21 ND ND ND
CYP2B6 23 ± 0.8 124 ± 17 0.19 ND ND ND
CYP2C19 22 ± 0.9 110 ± 17 0.20 3.0 ± 0.1 54 ± 7 0.06
CYP2D6 3.3 ± 0.4* 4.6 ± 1.9* 0.72 9.2 ± 0.5 2.8 ± 0.9 3.29
CYP3A4 2.4 ± 0.4* 10 ± 4.8* 0.24 0.8 ± 0.1* 45 ± 16* 0.02
R-MDEA (racemic MDEA) CYP1A2 10 ± 0.4 65 ± 11 0.15 ND ND ND
CYP2B6 12 ± 0.5 82 ± 13 0.15 ND ND ND
CYP2C19 10 ± 0.5 126 ± 6 0.08 ND ND ND
CYP2D6 3.2 ± 0.2* 6.5 ± 0.6* 0.49 4.4 ± 0.3 2.0 ± 0.6 2.20
CYP3A4 2.1 ± 0.2* 16 ± 2.4* 0.13 0.4 ± 0.2* 21 ± 5* 0.02
S-MDEA (racemic MDEA) CYP1A2 9.0 ± 0.4 32 ± 6 0.28 ND ND ND
CYP2B6 11 ± 0.7 53 ± 15 0.21 ND ND ND
CYP2C19 12 ± 0.4 31 ± 19 0.39 2.9 ± 0.3 25 ± 8 0.12
CYP2D6 2.2 ± 0.2* 11 ± 0.2* 0.20 4.8 ± 0.3 1.0 ± 0.3 4.80
CYP3A4 3.8 ± 0.3* 18 ± 1.7* 0.21 0.3 ± 0.08* 13 ± 4* 0.02
R-MDEA (single enantiomers) CYP1A2 13 ± 0.5 179 ± 21 0.07 ND ND ND
CYP2B6 18 ± 1.2 115 ± 34 0.16 ND ND ND
CYP2C19 15 ± 0.4 187 ± 19 0.08 2.4 ± 0.1 139 ± 20 0.02
CYP2D6 2.5 ± 0.5* 3.6 ± 2.7* 0.69 9.3 ± 0.2 1.4 ± 0.2 6.64
CYP3A4 13 ± 2.0* 76 ± 18* 0.17 1.1 ± 0.08* 38 ± 7* 0.03
S-MDEA (single enantiomers) CYP1A2 16 ± 0.8 126 ± 21 0.13 ND ND ND
CYP2B6 19 ± 0.8 99 ± 20 0.19 ND ND ND
CYP2C19 8.7 ± 1.5* 1.8 ± 0.9* 4.83 3.3 ± 0.1 18 ± 2.8 0.18
CYP2D6 5.1 ± 0.3 20 ± 5 0.26 9.5 ± 0.1 0.7 ± 0.07 13.57
CYP3A4
3.2 ± 0.4*
7.3 ± 2.5*
0.44
0.7 ± 0.2*
36 ± 8*
0.02

  • ND, not determined.

  • ↵* Kinetic data estimated according to eq. 2.