Table 3.
Total quenching* of 1O2 by pyridoxine derivatives and other physiological antioxidants
| Quencher/antioxidant | kq, M−1·s−1 | Conditions, solvent | Ref. |
|---|---|---|---|
| Pyridoxine | 10.3 (± 0.5) × 107 | pD = 7.4, D2O | This work |
| Pyridoxal | 8.7 (± 0.1) × 107 | pD = 7.4, D2O | This work |
| Pyridoxamine | 9.9 (± 0.2) × 107 | pD = 7.4, D2O | This work |
| Pyridoxal 5-phosphate | 6.2 (± 0.2) × 107 | pD = 7.4, d2O | This work |
| l-Methionine | 1.1 (± 0.1) × 107 | D2O | This work |
| Vitamin C | 0.83 × 107 | H2O, pH 6.8 | (26) |
| 15 × 107 | CD3OD | (27) | |
| Vitamin E | 10 × 107 | CCl4 | (28) |
| 3 × 107 | ClCF2CCl2F | (29) | |
| Glycyl-methionine | 1.5 × 107 | 50% CH3CN, 50% H2O | (30) |
| Glutathione | 0.087 × 107 | D2O | (31) |
| Cysteine | 5 × 107 | 75% D2O, 25% EtOH | (32) |
*
The quenching-rate constants, kq, reported in this work were calculated from time-resolved decays of 1O2 phosphorescence recorded after a single-pulse laser irradiation (19) of rose bengal in aerobic D2O solution containing the pyridoxine quencher.