| abstract |
A compound of general formula I wherein R2 is selected from the group consisting of hydrogen, halo, alkyl or aryl, wherein the alkyl or aryl are optionally substituted with one or more alkoxy, alkanoyl, nitro, cycloalkyl, alkenyl, alkynyl, acyloxy, alkyl or halogen atoms; R3 is a lipophilic group; one of R4 and R5 is a substance that contains a biologically active amino group selected from the group consisting of an amine-containing drug, a natural or non-natural amino acid, a peptide and a protein and the other of R4 and R5 is OR6, where R6 is selected from the group consisting of hydrogen, an alkali metal or a negative charge; X is oxygen or sulfur; And it is a natural or unnatural binding amino acid; n is zero or 1; and m is an integer from zero to 10. |