Table 2

Experimentally measured energy differences in activation energies for aliphatic P450 oxidation reactions

CompoundReferenceRegioselectivity PositionsMeasured Δ kcal/mol2-aPredicted Δ kcal/mol2-b
Ethylbenzene White et al., 1996 Primary/benzylic−4.39−4.58
α-Chloro-p-xylene Higgins et al., 2001 Benzylic/CI-methyl benzylic−0.74−1.31
2-Methylanisole Higgins et al., 2001 Benzylic/O-demethylation0.402.25
4-Methylanisole Higgins et al., 2001 Benzylic/O-demethylation0.722.21
1,3-Diphenylpropane Hjelmeland et al., 1977 Benzylic/secondary1.282.44
Hexane Morohashi et al., 1983 1/2 Hexanol−1.85−2.15
Octane Jones et al., 1990 1/2 Octanol−2.14−2.14
1-Phenyl-3-(4-fluorophenyl)propane Hjelmeland et al., 1977 Benzylic/substituted2-c 0.51−0.16
1-Phenyl-3-(4-methylphenyl)propane Hjelmeland et al., 1977 Benzylic/substituted2-c 0.0−0.34
1-Phenyl-3-(4-trifluoromethylphenyl)propane Hjelmeland et al., 1977 Benzylic/substituted2-c 1.810.82
  • 2-a  The energy difference as determined by taking the ln of the measured ratios and multiplying by 0.616, as described under Materials and Methods.

  • 2-b  The energy difference between the predicted activation energy for hydrogen atom abstractions based on Eq.2.

  • 2-c  Benzylic hydroxylation of the phenyl ring over benzylic hydroxylation of the substituted phenyl ring.