SHYFFA OSNOVANIYA (H. Schiff, is mute. biochemist, 1834 — 1915; synonym: the azomethine bases, imines) — organic compounds with the general formula R — With — R' = N — R" where radicals of R and R' can be hydrogen, alkyl or aryl, a R" — alkyl or aryl. Highways of the lake are formed as intermediate compounds in many enzymatic reactions, at a non-enzymatic glycosylation of proteins (see), during the fixing of proteins by formalin (see), etc. Disturbances of exchange of Sh. of the lake in a human body and animals initiate various patol. biochemical processes, napr, a non-enzymatic glycosylation of proteins at a diabetes mellitus (see a diabetes mellitus), a galactosemia (see) or formation of lipofuscins (see). Schiff bases are valuable products to l of l of organic synthesis, in t. - an ip-teza of pharmaceuticals.
Sh.'s education by the lake represents eurysynusic biochemical reaction since to carbonyl group With = About and
an amino group/N/N — N is inherent komplementar-
a nost; this reaction quickly proceeds in two stages as condensation (accession of amine to aldehyde or ketone and eliminating of water). For the first time reaction of formation of these organic compounds was carried out in 1864 by Schiff.
Highways of the lake are oily liquids or crystal connections, not water soluble, soluble in organic solvents (alcohol, ether, etc.). Communication With = N causes a characteristic strip of absorption in a range of combinational dispersion and in an infrared range. Highways of the lake have weak main properties and form salts with to-tami in the anhydrous environment; they are very labilna and in an aqueous medium are easily hydrolyzed to-tami to initial products. Highways of the lake have no reducing power, are steady against effect of alkalis (see), are easily hydrogenated on a double bond with formation of secondary amino, attach various connections containing mobile hydrogen (ketones, ethers, ketenes, etc.), form heterocyclic compounds, can be polymerized.
In a human body and animals reactions of transamination are followed by Sh.'s education by the lake (see) — interaction of pyridoxal phosphate and a piridoksaminfosfat with their substrates — amino acids and ketonic acids respectively; the reactions catalyzed the peptide-guide-rolazami (see) — in them the carbonyl group of a molecule of enzyme connects to an amino group of substrate; synthesis of amino acids (see) from aldehydes (see) with accession ag a miaka; transformation @-aminolevuli-new to - you in porphobilinogen (see. Bilious pigments). In a zrita lnokhm a pigment rhodopsin (see Rhodopsins) a retina (see Retinolum) the island a-Ketoglu-tarat with ammonia is connected with a proteinaceous part of a molecule through a s-amino group of the rest of a lysine (see) by means of Sh. forms Sh. the lake, a cut can be recovered by glutamatsintazy (KF 126.96.36.199); at biosynthesis of tryptophane (see) intermediate compounds Sh. of the lake also are. Schiff bases are formed at biosynthesis of alkaloids (see) as a result of 0 =, N = or S = aminomethylations of alcohols, amines or thiols (so-called Mannich reaction), in reactions of an isomerization (see Isomerases), in reactions of hydrogen transfer by means of dehydrogenases of amino acids (see Dehydrogenases) and aminoxidases (see Oxidases), at formation of insoluble lipidobelkovy complexes (pigments of aging, or lipofuscins) when the low-new aldehyde which is formed at peroxide oxidation of lipids forms Sh. of the lake with amino groups of protein. The major analytical reagent applied in biol. researches — and ingidrin (see) forms reactive Sh. with amino acids the lakes forming in turn colored compounds, intensity of coloring to-rykh measure colorimetric (see the Stake an orimet-riya). Most of III. the lake can be easily recovered the borgidri-house of sodium with formation of secondary amino, in to-rykh initial aldehydes are covalently connected with initial amino groups. This reaction lezhpt at the heart of widely used method of detection of Sh. of the lake in proteins is also applied to introduction of isotope tags to proteins.
446 SCHIFF REACTANT
Bibliography: Karrer P. A course of organic chemistry, the lane with it., JI., 1960; M e c-l e r D. Biokhimiya, the lane with English, t. 2 — 3, M., 1980. V. K. Gorodetsky.