Related Experiment Video
Updated: Aug 16, 2026

Real-time Analyses of Retinol Transport by the Membrane Receptor of Plasma Retinol Binding Protein
Published on: January 28, 2013
Physiological functions of vitamin E and biodiscrimination of its stereoisomers
1Institute of Environmental Science for Human Life, Ochanomizu University, Japan.
Abstract:
Vitamin E is recognized as a fat-soluble antioxidant able to scavenge oxygen radicals and to quench singlet oxygen. Of 8 analogues of vitamin E alpha-tocopherol has the highest biological activity. In addition, all-rac-alpha-tocopherol 2R-stereoisomers are more active than their 2S-counterparts. To cast light on the significance of this in vivo, we investigated the discrimination and distribution of alpha-tocopherol stereoisomers in rats using chiral-HPLC. Alpha-tocopherol was found to be absorbed from the small intestine without discrimination. After transfer to the liver, however, 2R-isomers are preferentially secreted into VLDL. In this discrimination the alpha-tocopherol transfer protein functions as a key substance.
More Related Videos
05:03Quantitative Analysis of Dietary Vitamin A Metabolites in Murine Ocular and Non-Ocular Tissues Using High-Performance Liquid Chromatography
Published on: December 27, 2024
08:18Methodology for Studying Interactions of Vitamin A Membrane Receptors and Opsin Protein with their Ligands in Generating the Retinylidene Protein
Published on: October 4, 2024
Related Concept Videos
Properties of Enantiomers and Optical Activity
Stereoisomerism of Cyclic Compounds
E1 Reaction: Stereochemistry and Regiochemistry
Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin D3(cholecalciferol).
Lipid-derived Compounds in the Human Body
Fat-soluble Vitamins
Fat-soluble vitamins, including vitamins A, D, E, and K, are required in minimal quantities, but their deficiencies can lead to severely abnormal physiological conditions. For example, vitamin A deficiency can cause night blindness, dry skin, delayed...
Vitamins