N-[4-(3-Aminopropyl)aminobutyl]-2-(.omega.-guanidino-fatty acid-amido)-2-substituted-ethanamides represented by the general formula ##STR1## wherein Y represents --CH.sub.2 --CH.sub.2 --, --CH.dbd.CH or ##STR2## R represents a hydrogen atom, an alkyl group of 1 to 4 carbon atoms which may have a hydroxyl group as substituent, or a benzyl group, and n is an integer of from 1 to 8, provided that when Y is ##STR3## and n is 4, R represents the groups other than the hydrogen atom; salt thereof having antitumor activity in experimental animal tumors and a process for the preparation thereof is provided.
N-[4-(3-Aminopropyl)aminobutyl]-2-(.omega.-guanidino-fatty acid-amido)-2-substituted-ethanamides represented by the general formula ##STR1## wherein Y represents --(CH.sub.2 --CH.sub.2 --, --CH.dbd.CH or ##STR2## R represents a hydrogen atom, an alkyl group of 1 to 4 carbon atoms which may have a hydroxyl group as substituent, or a benzyl group, and n is an integer of from 1 to 8, provided that when Y is ##STR3## and n is 4, R represents the groups other than the hydrogen atom; a salt thereof having antitumor activity in experimental animal tumors and a process for the preparation thereof is provided.