Vitamin E—Food Chemistry, Composition, and Analysis

Tropospheric Chemistry and Composition

The troposphere, the region of the Earth’s atmosphere in which we live and breath, is composed of many different kinds of gases. These components range from the abundant two-atom molecules O2 and N2, to larger and more reactive chemicals, which include vast numbers of different volatile organic compounds (VOCs). Concentrations of VOCs can be as high as one part per million by volume (10 , or pp...

Vitamin B12: chemistry and biochemistry.

Vitamin B12, the 'antipernicious anaemia factor', is required for human and animal metabolism. It was discovered in the late 1940s and its unique corrin ligand was revealed approx. 10 years later by X-ray crystallography. The B12-coenzymes are cofactors in various important enzymatic reactions and are particularly relevant in the metabolism of anaerobic microorganisms. Microorganisms are the on...

Atmospheric Composition, Chemistry, and Clouds

Venus’ atmosphere has a rich chemistry involving interactions among sulfur, chlorine, nitrogen, hydrogen, and oxygen radicals. The chemical regimes in the atmosphere range from ion-neutral reactions in the ionosphere to photochemistry in the middle atmosphere to thermal equilibrium chemistry and surface-atmosphere reactions in the lower atmosphere. This variety makes Venus an important planet t...

The Chemistry of Vitamin E

In a previous communication (1) some of us described the isolation from wheat germ oil of an alcohol, C&Hb002, having marked vitamin E activity, for which we proposed the name a-tocopherol. The substance itself was an oil, and was isolated in the form of the allophanate melting at 158-160’ from which it could be easily regenerated by alkaline hydrolysis. From it was also obtained a p-nitropheny...

Chemistry and enzymology of vitamin B12.