TETRAPEPTIDE DERIVATIVES OF DOLASTATIN AS ANTITUMOR AGENTS

摘要

The present invention provides antitumor peptides of formula (I): A-B-NR<3>-CHD-CH(OCH3)-CH2CO-E-K and the acid salts thereof. A is an amino acid residue selected from the group consisting of N-methyl-D-prolyl, N-methyl-D-homoprolyl and N, N-dimethyl-2 -ethylphenylglycyl, or an amino acid residue of the formula R<1>R<2>N-CHX-CO, wherein R<1> is a methyl group or an ethyl group, R<2> is a hydrogen atom, a methyl group or an ethyl group, and X is an alkyl group. B is an amino acid residue selected from the group consisting of valyl, isoleucyl, leucyl, and 2-t-butylglycyl. R<3> is a hydrogen atom or a methyl group. D is a normal or branched C2-C5-alkyl group. E is an amino acid residue selected from the group consisting of prolyl, homoprolyl, 5-methylprolyl, and phenylalanyl, or E is a residue derived from an amino acid comprising a pyrrolidine group. K is an alkoxy group or an amino group. An additional embodiment of the present invention is a method for treating a malignancy in a mammal, such as a human, comprising administering to the mammal an effective amount of a compound or compounds of the formula (I) in a pharmaceutically acceptable composition.