[New amino acid derivatives with oncolytic action].

A total of 27 new derivatives have been obtained by substitution on seven amino acids and betaines, respectively. The present experimental study examines the oncolytic and oncostatic action of four new amino acid compounds. Under experimental conditions in vitro the following remarkable properties of the chemical preparations can be ascertained on Ehrlich's tumor cells of the white mouse: 1. The oncolysis detected by micromorphology only occurs after an incubation of 4-6 hours, the transplantability of the tumor cells is lost much earlier. 2. The anaerobic glycolysis is in no case limited, the cell respiration is stimulated under the influence of amino acid compounds. 3. The Crabtree effect on Ehrlich ascites tumor cells is inhibited by the test substances. The irreversible damage caused by the new amino acid compounds to the Ehrlich tumor cells and observed in vitro only occurs with large excess of the substances. The mechanism of action may be due to a substrate-like excess inhibition, a disturbance of the amino acid sequence within the cell proteins being discussed. Therapeutic inhibition tests on experimental animal tumors have shown that an effect may only be expected after the application of high doses and prolonged administration. The extremely low general toxicity and the lack of any disturbance of the hematopoietic system permit a long-time application of the amino acid compounds.