HYDROXY-BUTYRIC ACIDS (oxybutane acids) — the oxidized butyric acids. One of isomers O. to. — D - beta and hydroxy-butyric to - that is a product incomplete biol, oxidations fat to - t in a liver of mammals, including and the person, and together with acetoacetic to - that and acetone combines in group of the organic compounds called by ketone bodies and which are intermediate products of exchange of fats, carbohydrates and proteins. Detection beta and hydroxy-butyric to - you served in an organism of mammals as the proof of existence of metabolic beta oxidation fatty acids (see) — one of the main ways of energy release.
The liver of vertebrata has ability to turn atsetil-KOA into D - beta and hydroxy-butyric to - that and with the help OVER - dependent D - beta oksibutiratdegidrogenazy (KF 1. 1. 1. 98; dehydrogenases D-2-hydroxy-fat to - t) to recover acetoacetic to - that to D - beta and hydroxy-butyric to - you. Formed beta and hydroxy-butyric to - that is brought by blood to peripheral fabrics where is oxidized in a cycle Tricarboxylic to - t (see. Tricarboxylic acids cycle ). Other isomer O. to. — beta and hydroxy-isobutyric to - that is an intermediate product in metabolic transformation valine (see) in suktsinil-KOA in a cycle of oxidation of amino acids.
Pier. the weight (weight) of O. to. 104,1, they exist in the form of the following isomers: alpha and hydroxy-butyric to - that [CH 3 CH 2 CH(OH)COOH], beta and hydroxy-butyric to - that [CH 3 CH(OH)CH 2 COOH], gamma and hydroxy-butyric to - that [CH 2 (OH) of CH 2 CH 2 COOH], alpha and hydroxy-isobutyric to - that [CH 3 C (CH 3 ) (OH) of COOH], beta and hydroxy-isobutyric to - that [CH 2 (OH) of CH(CH 3 ) COOH] and their optical isomerides.
DL - beta and hydroxy-butyric to - that represents siropoobrazny liquid, restrictedly water soluble, well soluble in alcohol and ether, but insoluble in benzene, t ° kip 130 ° (12 mm of mercury.). D - beta isomers O. to. crystallize in the form of hygroscopic monoclinical crystals with t°pl 49 — 50 °, their solutions in water rotate the plane of polarization of a light ray of [a]D15 to the left — 25,3 °; L - beta isomer — also crystal substance with [a]D15 +25,2 ° (in water). In addition to the general chemical properties characteristic of all oxyacids (see), O. to. have specific properties: beta and hydroxy-butyric to - that easily loses water, turning in crotonic to - that, and gamma and hydroxy-butyric to - that forms lactones (see). By the main method of definition of O. to. is chromatography (see); in urine beta and hydroxy-butyric to - that is defined by means of Gardt's test with preliminary oxidation in acetoacetic to - that, to-ruyu quantitatively defined with Sodium nitroprussidum (see. Ketone bodies ).
Bibliography: Lenindzher A. Biochemistry, the lane with English, M., 1976; F and z e r L. and F and z e r M. Organic chemistry, t. 1, page 91, 162, M., 1970.
N. V. Prokazova.