Table 1.
Chemical Properties and Reactivities of Glutathione, Cysteine, Hydropersulfide, Ascorbate, α-Tocopherol, and Linoleate Toward Biologically Relevant Free Radicals and Oxidants
| GSH | CySH | RSSH | Ascorbate | α-TOH | Linoleate | |
|---|---|---|---|---|---|---|
| D(S,O,C-H)a | 87 [1] | 86 [1] | 70 [2] | n.a. | 77 [3] | 75 [4] |
| Redox potentb | 920 [5] | 920 [6] | 680 [6] | 282 [6] | 500 [6] | 600 [7] |
| pKa | 8.93 [8] | 8.45 [8] | 5.45 [9] | 4.2 [10] | 13.1 [11] | |
| Log Pc | −6.4 [10] | −2.49 [10] | n.a. | −1.85 [10] | 3.36 [10] | n.a. |
| Rate constant kd | ||||||
| R• | 107 [1] | 0.3–5 × 107 [1] | 5 × 108 [12] | n.a. | n.a. | n.a. |
| RS• | 6 × 107 [13] | n.a. | 1 × 1010 [12] | 3 × 108 [14] | n.a. | 106∼107 [15] |
| HO• | 1.3 × 1010 [16] | 4.7 × 1010 [16] | n.a. | 1 × 1010 [16] | ∼1010 [17] | 109 [17] |
| RO• | 6.62 × 107 [1] | 1.15 × 108 [1] | 1 × 109 [12] | n.a. | ∼ 109 [17] | 9 × 109 [17] |
| RO2• | 4.24 × 103 [1] | 1.07 × 104 [1] | 2 × 106 [12] | 2x106 [17] | 3 × 106 [18] | 62 [19] |
| HO2• | 7.32 × 103 [1] | 1.81 × 104 [1] | n.a. | n.a. | n.a. | 1.2 × 103 [17] |
| CO3•− | 5.3 × 106 [16] | 1.6 × 107 [16] | n.a. | 1.1 × 109 [16] | n.a. | >2 × 105 [20] |
| NO2• | 2 × 107 [21] | 5 × 107 [21] | n.a. | 3.5 × 107 [16] | <106 [16] | >2 × 105 [20] |
| ONOOH | 1.3 × 103 [22] | 5.9 × 103 [23] | n.a. | n.a. | n.a. | n.a. |
| 1O2 | 2.4 × 106 [24] | 8.3 × 106 [24] | n.a. | 1.9 × 106 [25] | 2.8 × 108 [24] | 105 [26] |
| HOCl | 1.1 × 108 [27] | 3.1 × 108 [27] | n.a. | n.a. | n.a. | 18 [28] |
| H2O2 | 0.87 [29] | 0.84 [30] | n.a. | n.a. | n.a. | n.a. |
Numbers in brackets show references: [1] Denisov et al. (2009); [2] Benson (1978); [3] Mulder et al. (2005); [4] Pratt et al. (2003); [5] Madej and Wardman (2007); [6] Buettner (1993); [7] Koppenol (1990); [8] Winterbourn and Hampton (2008); [9] Benchoam et al. (2020); [10] Pub Chem; [11] Mukai (2007); [12] Chauvin et al. (2017); [13] Nauser et al. (2004); [14] Chatgilialoglu et al. (2014); [15] Chatgilialoglu (1990); [16] Pryor et al. (2006); [17] Simic et al. (1992); [18] Burton et al. (1985); [19] Howard and Ingold (1967); [20] Everett et al. (1996); [21] Ford et al. (2002); [22] Trujillo and Radi (2002); [23] Radi et al. (1991); [24] Di Mascio et al. (1991); [25] Mukai et al. (2012); [26] Doleiden et al. (1974); [27] Storkey et al. (2015); [28] Everett et al. (1996); [29] Winterbourn and Metodiewa (1999); and [30] Portillo-Ledesma et al. (2014). The data were obtained at ambient temperature in solution.
Bond dissociation energy obtained by calculation for S-H bonds of GSH, cysteine, and hydropersulfide; phenolic O-H bond of α-tocopherol; and bisallylic C-H bond of linoleate in kcal/mol.
One-electron redox potential in mV.
Partition coefficient.
Rate constant k for reactions of free radicals and nonradical oxidants with GSH, CySH, RSSH, ascorbate, α-TOH, and linoleate in M−1·s−1.
α-TOH, α-tocopherol; CySH, cysteine; GSH, glutathione; n.a., not available; RS•, thiyl radical; RSSH, hydropersulfide.