第十一章 维生素 课件.ppt

Chapter 12 Vitamin Vitamin Vitamins are among those nutrients that the human organism cannot synthesize from other dietary components. Many vitamins function biochemically as precursors in the synthesis of coenzymes necessary in human metabolism. Classification and Effect of Vitamin Structure of Some Vitamins Section 1. Lipid Soluble Vitamins Vitamin A Acetate Chemical name: (All-trans)-3,7-Dimethyl-9-(2,6,6-trimethyl-1-cyclohexene-1-yl)-2,4,6,8-nonatetraen-1-ol acetate. All-trans retinol acetate. Discovery of Vitamin A It was first recognized as a vitamin by McCollum and Davis in 1913 and 1915. It was synthesized in 1947 by two Dutch chemists. Studies of the mechanism of retinol in the visual process were not significantly productive until 1968 to 1972. The term Vitamin A is applied to compounds having biological activity like that of retinol (视黄醇). Vitamin A Vitamin A1 Retinol (视黄醇)Vitamin A2 3-dehydroretinol (3-脱氢视黄醇) ?-Carotene(胡萝卜素) Carotenes in plants can be changed into Vitamin A ( Provitamin A). There are at least 10 kinds of carotenes which can be changed into Vitamin A. α、?、γ-Carotene and zeaxanthin(玉米黄素) are most important. 2/3 of Vitamin A in human body come from ? -Carotene. Stability of Vitamin A Unstable to UV， easily be oxidized in air. Metabolism of Vitamin A Acetate Retinoic Acid Retinoic Acid, active metabolite of Vitamin A, has similar activity to Vitamin A, it mainly influences on bone growth and epithelial(上皮组织) metabolism. It has good effect in preventing cancer and anticancer. Retinoic Acid and its isomer 13Z-Retinoic Acid are in clinical use. Analogues of Retinoic Acid Retinamidoester and N-(4-Hydroxycarbophenyl)-retinamide can prevent precancerous change of cervix(宫颈), oral cavity(口腔) and esoph(食管). Vitamin A derivates synthesized by Chinese researcher. SAR of Vitamin A Synthesis of Vitamin A Pharmacology Action of Vitamin A Side effect o