Abstract
The oxidation of 1,4-diaminobutane, 1,5-diamino-pentane, 1,10 -diaminodencane of 1- and d-lysine catalyzed by plant amino oxidase was studied. Accumulation of carbonyl compounds as a result of the oxidations could be shown only with 1,10-diaminodecane as substrate. Evidence was obtained of the formation of [DELTA]1-pyrroline compounds from 1,4-diaminobutane, of 2,3,4,5-tetrahydropyridine compounds from 1,5-diaminopentane and of 2,3,4,5-tetrahydropicolinic acid from d- and 1-lysine. It is suggested that formation of these ring compounds is due to spontaneous cyclization of the aldehydes or of the aldimines which are the probable products of the enzyme-catalyzed reactions. The compounds formed as a result of the oxidation of 1,4-diaminobutane, 1,5-diaminopentane and of d- and 1-lysine were readily hydrogenated in presence of platinum black. Derivatives of pyrrolidine and piperidine were isolated from such hydrogenated reaction mixtures with 1,4-diaminobutane and 1,5-diaminopentane respectively as substrates. A derivative of dl-pipecolinic acid was isolated from hydrogenated reaction mixtures with dl-lysine as substrate. It is suggested that the amine oxidase-catalyzed oxidation of 1,4-diaminobutane, 1,5-diaminopentane and 1-lysine may represent the first stage in a biosynthesis of pyrrolidine and piperidine ring compounds. With 1-lysine as substrate this would result in the formation of 1-pipecolinic acid. The possibility that amine oxidase is concerned in the formation of alkaloids is discussed.