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Postabsorptive elimination of the various forms of vitamin E appears to play a key role in regulation of tissue tocopherol concentrations, but mechanisms of tocopherol metabolism have not been elucidated. Here we describe a pathway involving cytochrome P450-mediated omega-hydroxylation of the tocopherol phytyl side chain followed by stepwise removal of two- or three-carbon moieties, ultimately ...

Background: Although the population distribution of serum concentrations of -tocopherol has been described in the United States, little is known about the distribution of -tocopherol or the ratio of -tocopherol to -tocopherol. Objective: Our aim was to describe the distribution of serum concentrations of -tocopherol and -tocopherol in a nationally representative sample of US adults. Design: We ...

ABSTRACT: In this study the non-saponifiable matter of oils extracted from nine varieties of sunflower seed were subjected a series of chemical tests. The non-saponifiable matters were fractionated into a number of chemical classes of compounds namely sterols, 4 methyl sterols, triterpene alcohols, tocopherols and hydrocarbons. The two major and important classes of compounds consisting of ster...

One of the simplest methods for short-term handling and storage of fish is the refrigeration in combination with dip treatments. This study was conducted to determine the effect of pre-storage α-tocopherol acetate dipping treatments on lipid stability of refrigerated rainbow trout fillets. Trout fillets were dipped in α-tocopherol acetate solutions (200 and 500 mg kg-1 flesh) and subsequently s...

Tocopherols are amphipathic antioxidants synthesized exclusively by photosynthetic organisms. Tocopherol levels change significantly during plant growth and development and in response to stress, likely as a consequence of the altered expression of pathway-related genes. Homogentisate phytyltransferase (HPT) is a key enzyme limiting tocopherol biosynthesis in unstressed Arabidopsis leaves (E. C...

one of the simplest methods for short-term handling and storage of fish is the refrigeration in combination with dip treatments. this study was conducted to determine the effect of pre-storage α-tocopherol acetate dipping treatments on lipid stability of refrigerated rainbow trout fillets. trout fillets were dipped in α-tocopherol acetate solutions (200 and 500 mg kg-1 flesh) and subsequently s...

noise induced hearing loss (nihl) is one of the most important occupational disease worldwide. nihl has been found potentiate by simultaneous carbon monoxide (co) exposure. free radicals have been implicated in cochlear damage resulted from the exposure to noise and due to the co hypoxia. this study examined whether α-tocopherol administration, as a free radical scavenger, causes the attenuatio...

gamma-Tocopherol, the major form of dietary vitamin E, is absorbed in the intestine and is secreted in chylomicrons, which are then transferred to liver lysosomes. Most gamma-tocopherol is transferred to liver microsomes and is catabolized by cytochrome p450. Due to the hydrophobicity of gamma-tocopherol, a binding and transfer protein is plausible, but none have yet been isolated and character...

The objective of this study was to evaluate the dynamics of tocopherols in cotyledons and radicles from sunflower seeds with high and low total tocopherol content, mainly in the α-tocopherol form, and from seeds with increased proportions of β-, γ-, and δ-tocopherol, both under dark and light conditions. Tocopherol content was measured every 24 h from 1 to 12 days after sowing. In all cases, th...