Table 1.

Bimolecular rates of scavenging of retinoid cation radicals by tocopherols, trolox and urate. To determine the bimolecular rate constants of interactions between tocopherols and retinoid cation radicals, both reactants were solubilized in benzene. To determine the bimolecular rate constants of interactions between retinoid cation radicals and trolox or urate, the retinoids were incorporated into Triton X-100 micelles, whereas hydrophilic antioxidants were solubilized directly in 10 mM of phosphate buffer pH 7.0.

	Bimolecular Rates of Scavenging of Retinoid Radical Cations (108 M−1·s−1)
	Retinal Cation Radical	Retinoic Acid Cation Radical	Retinol Cation Radical
α-Tocopherol	80.2 ± 3.2	55.6 ± 2.4	0.80 ± 0.45
β-Tocopherol	67.3 ± 8.3	55.2 ± 2.4	1.6 ± 0.9
γ-Tocopherol	81.3 ± 10.2	47.2 ± 2.2	0.10 ± 0.06
δ-Tocopherol	76.0 ± 4.5	0.28 ± 0.22	0.08 ± 0.01
Trolox	1.90 ± 0.85	3.57 ± 0.04	0.46 ± 0.03
Urate	6.66 ± 0.02	7.81 ± 0.01	1.10 ± 0.10