Diamines

Diamines, hydrocarbons in which two hydrogen atoms are replaced by NH₂ groups. Only compounds in which both amino groups are attached to different carbon atoms are stable. D. are obtained by the reduction of dinitro compounds, dicyano compounds, dioximes, etc. D. form salts with two equivalents of acid. The number of D. found in nature is very small. Besides tetramethylenediamine (putrescine) and pentamethylenediamine (cadaverine), found in the putrefaction of protein substances, only hexamethylenediamine, found in the putrefaction of meat, tetramethylputrescine, isolated from the plant Hyoscyamus muticus by Willstätter, and trimethylenediamine, formed during the splitting of spermine, are known. The small number of natural D. is due to the small number of diamino acids contained in proteins, which serve as material for the formation of D. by decarboxylation (removal of CO₂); lysine forms cadaverine, ornithine, which is part of the arginine molecule, forms putrescine. Various types of bacteria, both pathogenic and non-pathogenic (the presence of D. in some types of cheese), have the ability to decarboxylate diamino acids. The formation of D. under the influence of cultures of tetanus, cholera, Finkler-Prior's vibrio, Bacillus mesentericus vulgatus, and putrefactive bacteria is characteristic. But some higher plants are also capable of producing D. In some cases with cystinuria, the excretion of diamines with urine and feces is observed. D. easily pass into heterocyclic compounds, which are the simplest alkaloids (pyrrolidine, piperidine and their homologs): H₂C-CH₂, H₂C-CH₂, H₂C-CH₂, H₂N-NH₂, putrescine CH₂/\CH₂, H₂N-NH₂, cadaverine H₂C-CH₂+NH₂; \/NH₂ pyrrolidine CH₂/\CH₂, H₂C-CH₂+NH₂,. H₂C-CH₂ \/NH₂ piperidine This may serve as an explanation for the formation in plants of some alkaloids from proteins through the stage of D. D. are relatively non-toxic. When separating the amines found in the body by the method of Kossel and Kutscher (Kossel, Kutscher), D. are found together with lysine, choline, and betaines in the lysine fraction, i.e., the fraction of substances precipitated by phosphotungstic acid and not precipitated by silver nitrate in the presence of caustic lime.

H₂C-CH₂, H₂C-CH₂, H₂C-CH₂, H₂N-NH₂, putrescine CH₂/\CH₂, H₂N-NH₂, cadaverine H₂C-CH₂+NH₂; \/NH₂ pyrrolidine CH₂/\CH₂, H₂C-CH₂+NH₂,. H₂C-CH₂ \/NH₂ piperidine This may serve as an explanation for the formation in plants of some alkaloids from proteins through the stage of D. D. are relatively non-toxic. When separating the amines found in the body by the method of Kossel and Kutscher (Kossel, Kutscher), D. are found together with lysine, choline, and betaines in the lysine fraction, i.e., the fraction of substances precipitated by phosphotungstic acid and not precipitated by silver nitrate in the presence of caustic lime.