Chemical Structure and Properties of TOCOPHEROL


NATURAL TOCOPHEROL:

Chemical Structure and Properties

1) Chemical structure and homologues

Natural TOCOPHEROL exists as a mixture of 4 homologues, Alpha, Beta, Gamma, Delta - available as a mixed product known as MIXED TOCOPHEROL - which is also known as vitamin E. Riken Vitamin Co., Ltd. supplies TOCOPHEROL products and specialties according to requirements by separating or combining the homologues using unique technology.

Homologues	R1	R2	R3
Alpha- TOCOPHEROL	CH3	CH3	CH3
Beta- TOCOPHEROL	CH3	H	CH3
Gamma- TOCOPHEROL	H	CH3	CH3
Delta- TOCOPHEROL	H	H	CH3

2) Comparison of antioxidant activity of homologues

Alpha-Toc has strong vitamin E activity, while Beta, Gamma, and Delta-Toc have strong antioxidant activity outside the body (in foodstuffs etc.). Therefore, Toc preparations which have a high Alpha-Toc content are suitable for health foods and vitamin E enrichment.

Biological and Antioxidant Activities of TOCOPHEROLS

Kind of TOC.	Biological activity (IU/mg)	Antioxidant activity (with d-Alpha-TOC as 100)
dl-Alpha-Toc acet.	1	0
d-Alpha-Toc acet.	1.36	0
dl-Alpha-Toc	1.1	100
d-Alpha-Toc	1.49	100
d-Beta-Toe	0.75	130
d-Gamma-Toc	0.15	200
d-Delta-Toc	0.05	300-500
dl-form = synthetic, d-form = natural

A schale oven test was carried out to examine the antioxidant activity of each homologue on lard. As a result, when comparing the days on which the POV values reached 50, the extent of antioxidant activity was in the following order: Delta > Gamma, Beta > Alpha. It us considered that MIXED TOCOPHEROL with a high content of Delta toc or with a high content of Delta-Toc and Gamma-Toc are suitable for use as antioxidant in foods.

Comparison of Antioxidant Activity of Related Products

(Amount added: 210 ppm in oil 20g of oil in a 9 ø cm Petri-schale was kept in a dark place at 60°C).

Alpha-Toc has weak antioxidant activity, which is true of synthetic TOCOPHEROL (dl-Alpha-Toc). Interestingly however, it is also known that the addition of a large amount of Alpha-Toc accelerates oxidation. Care must be taken in using dl-Alpha-Toc, bind a lower ratio of Alpha-Toc is favorable also in the case of natural MIXID Toc.

Comparison of Antioxidant Activity of Related Products

(Amount added: 210 ppm in oil 20g of oil in a 9 ø cm Petri-schale was kept in a dark place at 60°C)

Riken now supplies the following:
(1) Mixed Toc: (E-Oil) which possesses antioxidant activity.
(2)Toc specialties (E-oil, Super and E-Oil Gold) in which the composition of homologues is adjusted to exhibit greater antioxidant activity.
(3) Other Toc Products which contain a large amount of Alpha-Toc of high biological activity.

3) Properties
TOCOPHEROLS are transparent, viscous, oily liquids with slightly characteristic odor, and have colors ranging between light yellow to reddish brown. They are insoluble in water. but soluble in organic solvents such as ethanol, chloroform and hexane. The color changes gradually into dark brown after contact with air or light though it dose not alter the antioxidant activity.