As natural antioxidant

Tocotrienols differ from tocopherols by the presence of three isolated double bonds in the branched alkyl side chain. Oxidation of tocopherol leads to ring opening and the formation of tocoquinones that show an intense red color. This species is a significant contributor to color quaUty problems in oils that have been abused. Tocopherols function as natural antioxidants (qv). An important factor in their activity is their slow reaction rate with oxygen relative to combination with other free radicals (11). 

Lopez-Velez M, Martmez-Martmez F and Del Valle-Ribes C. 2003. The study of phenolic compounds as natural antioxidants in wine. Crit Rev Food Sci Nutr 43(3) 233—244. 

Bohm, FI. et al., Flavonols, flavone and anthocyanins as natural antioxidants of food and their possible role in the prevention of chronic diseases, Z. Ernahrungsw., 37, 147, 1998. 

Dry clean tanshen rhizomes were powdered and extracted with hexane for three days at room temperature. The hexane solution was kept overnight and then filtered. After removal of the solvent a residue was obtained which was separated into seven colored fractions by column chromatography with silica gel. Miltirone was isolated by preparative tic from fraction 1 (light red) using hexane ethyl acetate (4 1) followed by benzene-acetone (20 1). The product obtained was recrystallized from ethylacetate, m.p. 100-101°C. Its structure was confirmed by mass spectrum, NMR, IR and UV spectra which agree quite closely with those of Ho et al [76], Miltirone showed antioxidant behavior comparable to that of the commonly used phenolics BHT and BEA [77], The antioxidant activity of miltirone in lard at 100°C was determined with a Rancimat. Miltirone and other related compounds may have the potential of being used as natural antioxidants in food and cosmetics. 

Padmashree, A., Roopa, N., Semwal, A.D., Sharma, G.K., Agathian, G. and Bawa, A.S. (2007) Star-anise (lllicium verum) and black caraway (Carum nigrum) as natural antioxidants. Food Chemistry 104(1), 59-66. 

Dorman, H.J.D., Deans, S.C., Noble, R.C. and Surai, P. (1995) Evaluation of in vitro plant essential oil as natural antioxidants. Journal of Essential Oil Research 7, 645-651. 

Hamzawi, L.F. 1990. Role of phospholipids and alpha-tocopherol as natural antioxidants in buffalo butterfat. Milchwissenschaft. 45, 95-97. 

Tocopherols are considered as natural antioxidants for lipid-containing foods and marketed as all natural. They are permitted in food application according to GMP regulations (21CFR 182.3890). Natural tocopherols are limited to 0.03% (300 ppm) in animal fats (9 CFR 318.7). As most vegetable oils naturally contain tocopherols, the addition of this antioxidant may pose prooxidant effects. 

The distillate obtained from sunflower oil may be sold to pharmaceutical companies for tocopherol and sterol isolation. Tocopherols may be used as natural antioxidants or may be converted to vitamin E by methylating the heterocyclic ring. The interest in phytosterols is caused by the high potential of some of them to inhibit intestinal cholesterol absorption. 

Camosine as Natural Antioxidant and Neuroprotector Biological Functions and Possible Clinical Use... 

M.A. Babizhayev et al., L-camosine (P-alanyl-L-histidine) and carcinine (P-alanyl-histamine) act as natural antioxidants with hydroxyl-radical-scavenging and lipid-peroxidase activities. Biochem. J., 304(1994) 509-516. 

Mixed tocopherols can be added dispersed in dry raw materials or suspended in water or mixed with ethanol as a carrier (O Brien and Robertson, 1993 Six, 1994). Typical usage levels are 150-450 pg/g. Partly, this large range of different addition levels is due to the large range of tocopherol and tocotrienol contents of the raw materials (Cort et al., 1983) and their susceptibility to oxidation. Often, tocopherols and tocotrienols are added mixed with other compounds such as ascorbic acid or chelating agents that enhance the effect of tocopherols as natural antioxidants (Six, 1994). 

In weakly acidic and neutral media the reactions proceed at a lower rate. Reduc-tones (4.55-4.57), compounds with the carbonyl group vicinal to an endiol moiety, which are formed, are stable at pH < 6 and act as natural antioxidants. They transform into deoxysugars, uloses (5.58). The latter undergo cyclization into 5-hydroxymeth-ylfuran-2-aldehyde (5.62). Corresponding osuloses (5.63) in similar sequences of transformations yield diacetylformosine (5.69). 

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