Structure and physico-chemical properties of vitamin D

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Since the discovery of vitamin D has passed half a century. During this period studied-reaching influence of the drug on the body, but its mechanism of action for a long time remained unclear. Only during the last decade, a period of slow accumulation of knowledge about vitamin changed rapid and effective development of research for decryption mechanism of action of this vitamin. Difficulties study was attributed to the fact that the physiological effect of vitamin D is manifested in very small quantities, which are impossible to capture any chemical methods. Significant progress in the study of the metabolism of vitamin D has been achieved with the introduction into practice of scientific research labeled calciferol (Kodicek, 1956; De Luca, 1967, 1969). Using labeled vitamin D with high specific radioactivity gave an opportunity with the introduction of a paltry share of its experimental animals to trace the distribution of the drug not only between different tissues in the body, but also between subcellular fractions of the nucleus, mitochondria and mix (miloserdova, 1971).
A certain role in the study of the metabolism of vitamin D played the opening of methods excretion of this vitamin and products of its metabolism of tissues, divided by thin-layer or column chromatography (Norman, De Luca, 1963, 1964).
These modern research methods made it possible to study a number of issues related to the exchange of vitamin D and the mechanism of its action in the body: 1) comparative physiological activity of vitamins of group D and their metabolites; 2) the conversion of vitamin D into its active form and its chemical identity; 3) localization of vitamin and its metabolites in certain tissues, and cellular and subcellular structures.
The rapid development of molecular biology over the past decade helped to decipher the structure and mechanism of action of many biologically active substances. However, in the study of fat-soluble vitamins and especially Genesis toxic effects of vitamin d, progress has been more modest. However, recent studies conducted in many countries of the world, has created a real basis for the development of the mechanism of action of this essential vitamin at the molecular level.
B now physico-chemical properties of vitamin D in detail and widely reported in surveys and monographs (Berezovsky, 1959; L. and M. Fisher, 1964; Serov, and others, 1974, and others). In this regard, we present information about vitamin D directly related to the physiological and toxic effects of this drug on a child's body.
There are several types of vitamin D (D1, D2, D3, D4, D5, D6, d), which are found in natural sources - products of plant and animal origin, with the exception of vitamin D5 obtained by synthetic method. The chemical structure of vitamins of group D (calciferol) are derivatives of the 6- (3-hydroxy-10-Meilenstein-5-these-len)-7-(13-metalhydride-3-ilen)-ethane, having in 17th position aliphatic branched chain from 8-10 carbohydrate atoms (Fig. 1).
Molecule of vitamin D are two independent ring system: cyclohexane ring (a) and gerenzano nucleus consisting of two condensed-ring - cyclohexane (C) and Cyclopentanone (E) (Berezovsky, 1959). These two systems are connected ethylene bridge. Individual vitamins of group D differ from each other structure lateral hydrocarbon aliphatic chain, which is connected with the ring D in the 17th position.