| abstract |
The present invention is directed to compounds of general formula (I), wherein R1, R2, R3 and X may be the same or different, and wherein R1, R2 represent hydrogen, an amino acid, peptidyl, alkyl or aryl residue; R3 represents hydroxy, lower alkoxy, or an -NR31R32 residue, where R31, R32 represent independently hydrogen, an aminoacid, peptidyl, alkyl or aryl residue; X represents an amino acid or a peptide; R4 represents hydrogen, hydroxy, amino or C1-C4 alkyl; m represents a number between 0 and 5; R5 represents an optionally substituted saturated or unsaturated mono- or bicyclic moiety which may contain one or more heteroatoms, a C1-C11 alkyl group which may have substitutions or intermittent heteroatoms, their tautomers, optical isomers, pharmaceutically acceptable salts and prodrugs as well as their production and their use as medicaments. |