Page 304 - The Toxicology of Fishes

284 The Toxicology of Fishes

A OH OH
O O – + O OH
5 4 1 –e , –H O –e – O O
HO 3 2 HO HO
6
–
+e , +H + +e –
– O OH O O O O
Ascorbate Ascorbyl radical Dehydroascorbate

B designated R below
CH 3
HO CH 3
( CH CH CH CH ) H
CH 2 2 2 2 3
H C O CH 3
3
CH 3

CH 3
O?
R
C O
H 3
CH 3
CH 3
α - Tocopheryl radical

C 18 ·
3 ·
17 16
13 · 9 · 1 ·
1
β-Carotene 9 13
16 · 17 ·
3 5
18

Lycopene

3 5 7 9 11 13 15 13 · 9 · 5 · 1 ·
1
2 4 6 8 10 12 14 15 ·

O
OH

Astaxanthin
HO
O
FIGURE 6.3 Low-molecular-weight antioxidants. (A) Ascorbate (vitamin C) and its one-electron (ascorbyl radical) and
two-electron (dehydroascorbate) oxidation products. (B) α-Tocopherol (vitamin E) and its radical product. (C) Representative
carotenoids.