The Constitution and Synthesis of Spermidine, a Newly Discovered Base Isolated from Animal Tissues.

THE presence of an unidentified base in the mother-liquors after the isolation of spermine phosphate from tissue extracts was originally observed by M. C. Rosenheim and 0. Rosenheim during their early work on spermine and has already been reported [Dudley, Rosenheim and Rosenheim, 1924]. This base has been given the name spermidine since it not only occurs in association with spermine but also has been found to be structurally related to the latter substance. Its phosphate is much more soluble than that of spermine and crystallises from the 25 % alcoholic mother-liquor, after the removal of spermine phosphate, on increasing the concentration of alcohol to about 50 %. The material employed in the present investigation was isolated by this procedure during the large scale preparation from ox pancreas of the spermine used in our recently published work on the constitution of the latter base [Dudley and Rosenheim, 1925; Dudley, Rosenheim and Starling, 1926]. The yield of spermidine phosphate is extremely small, being only one-tenth of that of spermine phosphate, namely about 2 g. from 100 kg. pancreas. Only 10 g. of spermidine phosphate were available but, aided by our recently acquired knowledge of the constitution of spermine, we were able to arrive at a probable constitutional formula for the base, and then to prove its correctness by synthesis. The properties of spermidine are very similar to those of spermine. This is demonstrated in a general way by the fact that it accompanies spermine through all the stages of isolation from tissue extracts by the three methods already described [Dudley, Rosenheim and Rosenheim, 1924]. Like spermine it gives a pyrrole 'reaction, it appears in the lysine fraction on applying the method of Kossel and Kutscher, its phosphotungstate is insoluble in acetone, it is optically inactive, it does not reduce permanganate in faintly acid solution