Acetate, vitamin antioxidant activity

N.A. Pinus albicaulis Engelm. P. contorta Dougl. ex. Loud. P. mugo Turra var. pumilio P. palustris Mill. P. strobus L. Bishomophinolenic acid, resins, mallol, bomeol acetate, tannins, vitamin A, vitamin C, galactose, alpha-pinenes, beta-pinenes, anthocyanin.8102 Relieve fever, bronchial and nasal congestion, improve blood flow. Anthocyanin from bark has antioxidant activity, inhibits the enzymes that cause inflammation. 

Table I shows the results of a DPPH radical-scavenging assay on each of the whole-cranberry extracts prepared by Mediods 1 and 2. For whole cranberries, the highest antioxidant activity was observed in ethyl acetate extracts prepared by both methods, with an IC50 value of 0.033 mg/mL for the ethyl acetate extract prepared by Method 2. The ethyl acetate fraction was about twice as effective at radical scavenging as the whole-berry extract (IC50 = 0.078 mg/mL). Kinetics of these reactions were slow compared to the standard. Vitamin E for all cranberry extracts, radical scavenging occurred over a period of approximately one hour as compared to several minutes for vitamin E.

H. Uzun. Vitamin e has a dual effect of anti-inflammatory and antioxidant activities in acetic acid-induced ulcerative colitis in rats. Canadian Journal of Surgery 54(5), 333-338 (2011). 

It should be noted that pharmacological vitamin E is not a free natural RRR-a-tocopherol or synthetic All rac a-tocopherol but its acetate ester. a-Tocopheryl acetate has the phenolic hydroxyl group blocked and therefore, is not a genuine antioxidant, but this compound is very rapidly hydrolyzed in vivo into a-tocopherol. It is interesting that the biological activity of a-tocopheryl acetate is the same as that of a-tocopherol in humans but significantly lower in rats [30]. ( A man is not a rat Professor KU Ingold.)... 

Table XL Comparative Activity on Antioxidants on Crystalline Vitamin A Acetate...

Vitamin E (a-tocopherol), a potent antioxidant, appears to offer protection against injuries caused by 02, 03, and N02, and nitrosamine formation. Male rats supplemented with daily doses of 100 mg tocopheryl acetate and exposed to 1.0 ppm 03 have been shown to survive longer than vitamin E-deficient rats. The action of 03 is attributed in part at least to free radical formation. In addition, there is sufficient evidence that vitamin E protects phospholipids of microsomal and mitochondrial membranes from perox-idative damage by reacting with free radicals. Because lipid peroxidation is associated with decrease in oxidase activities, it is expected that the enzyme activity is affected by dietary vitamin E. Maximum activity has been observed when diets included both polyunsaturated fatty acids and vitamin E. 

The in vitro oxidation products from tocopherol have been studied in detail although less is known about its in vivo metabolism. The oxidation of a-tocopherol is light-catalysed and accelerated by unsaturated fatty acids, metal salts and alkali. The structure of many of the products from chemical oxidation has been established (ref. 98). It is used in the form of the unnatural acetate in which form it may well be more chemically stable although the manifestation of antioxidancy requires the presence of the free phenol since its radical is stabilised by resonance and by steric effects with the participation of several contributory structures. It has been suggested, as mentioned earlier, that the activity of vitamins E and C are related synergistically and evidence from pulse radiolysis has supported this augmenting interaction on the effect of vitamin E (ref.130), depicted in the equation. 

Enzymic conditions by an NADH system could reform vitamin C. Although the biological activity, presumably its antioxidancy, is said to be preserved in the acetate this is almost lost in its ethers and thus the phenolic group is a vital functional group. 

The d-form of the vitamin is the most active. Any studies of vitamin supplementation, and their subsequent effects in various muscle foods, must acknowledge the form of tocopherol fed before conclusions can be drawn regarding dietary uptake and antioxidant efficiency, d-a-tocopherol or its ester is more readily assimilated into tissues than the racemic (dl) form (Hidiroglou et al., 1988). Burton et al. (1988) have demonstrated that the uptake of the free phenol and acetate forms of d-a-tocopherol are equivalent. Marusich et al. (1975) reported that dl-a-tocopherol and dl-a-tocopheryl acetate were equivalent in terms of uptake by chicken liver and breast muscle, and resulted in similar oxidative stabilities within the tissue types. 

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