DNA-binding indole derivatives, their prodrugs and immunoconjugates as anticancer agents

A compound of the formula:

• R.sub.1 --(C(O)--R.sub.2 --R.sub.3 --NH).sub.m --(C(O)--R.sub.3 --NH).sub.n --R.sub.4
• wherein:
• R.sub.1 is selected from the group consisting of:
• ##STR9## wherein:
• each R.sub.2 is the same or different and is a valence bond or a divalent hydrocarbyl radical;
• each R.sub.3 is the same or different and is a divalent monocyclic or bicyclic heterocyclic aromatic radical;
• m and n are integers from 0 to 3, where m+n.ltoreq.3;
• and
• R.sub.4 is independently:
• Z where Z is either X or Y, where X is a structure of the Formula I, ##STR10## and Y is a structure of the Formula II, ##STR11## or C(O)R.sub.5, where R.sub.5 is independently:
• NH.sub.2 ;
• C.sub.1 -C.sub.6 alkyl;
• C.sub.1 -C.sub.6 hydroxyalkyl;
• C.sub.1 -C.sub.6 hydroxycycloalkyl;
• hydroxyphenyl;
• hydroxymethylphenyl;
• hydroxybenzyl;
• C.sub.1 -C.sub.6 aminoalkyl;
• C.sub.1 -C.sub.6 alkylaminoC.sub.1 -C.sub.6 alkyl;
• di-(C.sub.1 -C.sub.6)-alkylaminoC.sub.1 -C.sub.6 alkyl;
• C.sub.1 -C.sub.6 ureidoalkyl;
• a C.sub.1 -C.sub.6 alkyl group carrying a positively charged substituent selected from the group consisting of an amidinium group, a guanadinium group, a secondary aminium salt, a tertiary aminium salt, a quaternary ammonium salt, a sulfonium group, and a phosphonium group;
• C.sub.1 -C.sub.6 alkyl-NHZ;
• C.sub.1 -C.sub.6 cycloalkyl-NHZ;
• phenyl-NHZ;
• --CH.sub.2 -phenyl-NHZ;
• -phenyl-CH.sub.2 --NHZ;
• C.sub.1 -C.sub.6 alkyl-OR.sub.6 ;
• C.sub.1 -C.sub.6 cycloalkyl-OR.sub.6 ;
• phenyl-OR.sub.6 ;
• --CH.sub.2 -phenyl-OR.sub.6 ;
• or -phenyl-CH.sub.2 --OR.sub.6, where R.sub.6 is selected from the group consisting of:
• ##STR12## provided that, when R.sub.5 is NH.sub.2 or C.sub.1 -C.sub.6 alkyl:
• when m+n=2 and both R.sub.3 's are indole.