CARBAMIC CONNECTIONS — derivatives of carbamic (karbamidovy) acid (H 2 N • COOH), mainly its salts (carbamates) and ethers. In medicine are used as disinfecting and pharmaceuticals. Fosforilirovannye K. pages play a large role in a metabolism at animals and microorganisms.
From salts carbamic to - you are most known ammonium carbamate (H 2 N • COONH 4 ), present usually at commercial drugs of ammonium carbonate as impurity.
Esters carbamic to - you are collectively called urethanes. Some of them find application in medicine as calming and hypnagogues, napr, ethyl ether carbamic to - you, metilpropilkarbinolovy ether carbamic to - you and feniluretan.
In an experiment it is established that urethanes detain growth of some tumors at laboratory animals. However attempts to apply urethanes in clinic to treatment of malignant tumors did not give considerable effect; temporary remissions manage to be received only at treatment of myeloid leukemia. It was at the same time shown that urethanes are capable to cause in mice of a tumor of lungs and, thus, shall be carried to carcinogenic substances (see. Oncogenous substances ).
In an intermediate metabolism of substances at animals and microorganisms plays a large role fosforilirovanny derivative carbamic to - you — karbamoilfosfat. Its synthesis is carried out by two enzymes. One of them — a carbamate kinase (KF 18.104.22.168) is localized in mitochondrions and catalyzes reaction
Other enzyme is in cytosol and uses a glutamine as the donor of ammonium: glutamine + CO 2 + ATP —> karbamoilfosfat + glutaminic to - that + ADF.
Karbamoilfosfat — labile connection, a half-cycle of its disintegration apprx. 40 min. (37 °, pH 7,4). Formation of a karbamoilfosfat is an initial stage of utilization of ammonia for synthesis arginine (see) and pirimidinovy bases (see).
Ornitin-karbamoiltransferaza (KF 2. 1. 3. 3) catalyzes formation of citrulline from a karbamoilfosfat and ornithine. As a result of the subsequent reactions the arginine which is hydrolyzed under the influence of an arginase (KF 22.214.171.124) to ornithine is formed and urea (see). Aspartat-karbamoiltransferaza (KF 126.96.36.199) is catalyzed by education from a karbamoilfosfat and asparaginic to - you karbamoilasparaginovy to - you. Further under the influence of a digidroorotaza (KF 188.8.131.52) it is formed dihydroorotic to - that, and of the last — orotovy to - that (salts a cut find application as pharmaceuticals); such is a way of synthesis of the pirimidinovy bases.
Use of carbamic connections in disinfection
To. villages have insecticidal and acaricidal properties and are applied in agriculture, and also in life to extermination of synanthropic insects and mites. As insecticides To. pages are applied in the form of the moistened powders, dust and concentrates of emulsions. Their shortcoming is hypertoxity for hematothermal animals. Carbamates are quite widely used in quality herbicides (see). Alfa-Naftil-N-metilkarbamat (sevin, carboaryl) is effective concerning ixodic mites, cockroaches, a moth, fleas, bed bugs, an imago of louses; however in view of its gonadotropic action on hematothermal animals its use for extermination of insects in premises is forbidden. 2-Izopropoksifenil-N-metilkarbamat (baygon, propoksur) is an insecticide of a broad spectrum of activity and is used for fight against an imago of mosquitoes, cockroaches, etc. 2-(1', the 3rd '-Dioksolanil-2') - phenyl - N - marked a carbamate (dioksokarb, famid) is applied to fight against cockroaches, flies, ticks and other arthropods. Meta-methylphenyl-N - methyl carbamate and 40 — 45% of its para-isomer (dikrezit) mix of 55% is effective concerning many species of insects and mites, and especially concerning louses at all stages of development.
Bibliography Vashkov V. I., etc. Insecticides and their use in medical practice, M., 1965, bibliogr.; To at r and N of N y y A. I. and Pauline-with to and I am M. A. Issledovaniye of pesticides as mutagens of external environment, Kiev, 1976, bibliogr.; Millers of H. N. Himiya and technology of pesticides, M., 1974.
S. S. Debov, L. M. Ginodman; Yu. P. Volkov (epid.).