FUMARIC ACID

From Big Medical Encyclopedia

FUMARIC ACID —

ethylene - 1,2-dicarboxylic acid, a trance-butendiovaya acid, HOOCCH-CHCOOH, unsaturated dibasic acid. T. to. is • one of components of the major recycling — a cycle tricarboxylic to - t (see. Tricarboxylic acids cycle). It is formed in an organism of all highest animals of succinic acid (see) under the influence of sou ktsinat dehydrogenases (see) and turns into malic acid {see) with the participation of enzyme fumarates-tidratazy (fumarases; KF 4.2.1.2).

Fumarates - hydratase is the enzyme absolutely specific concerning substrate and reaction product. Besides, she finds also stereospecificity of two types: affects only one of two geometrical isomers F. to. also forms only L-apple to - that. 'The molecule fumarates - hydratases consists of 4 subunits, each of to-rykh contains three suljfgidril-ny groups (see); pier. weight (weight; enzyme it is equal to 200 Ltd companies.

T. to. it is formed also in a cycle of urea (see) and at oxidation of amino acids of phenylalanine (see), tyrosine * (see), a leucine (see), tryptophane «(see) and a lysine (see). Formed in all cases F. to. comes to a cycle tricarboxylic to - t. In nek-ry plants and microorganisms F. to. it is formed from asparaginic to - you under the influence of an aspartaza (KF 4.3.1.1), at animals this enzyme is absent.

T. to. represents colourless crystal substance with £ °pl 287 °, at a temperature of 290 ° it is sublimated. It is a rastvorima in water and ether, not a rastvorima in chloroform and benzene. T. to. has chemical properties dicarbonic to - t and properties of connections with a double bond in a molecule. Receive F. to. an isomerization maleic to - you, edges are it cis-stereoisomer (see the Isomerism).

T. to. it is used in the food industry as substitute lemon and wine to - t, in production of synthetic drying oils p plasticizers.

Bibliography: Lenindzher A. Biokhi

a miya, the lane with English, page 409, M., 1976; R about e r t with D. and To and with e r and about M. Fundamentals of organic chemistry, the lane with English, t. 1 — 2, M., 1978. N. V. Prokazova.

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