Synthesis and biological activity of O56-substituted carboxyesters and carboxamides of teicoplanin aglycone.

A series of O56-substituted carboxyester or carboxyamide derivatives of deglucoteicoplanin (TD) was prepared by condensation of the 56-hydroxyl function with various alkylating agents of general formula RBr, where R represents functional groups with different physico-chemical properties. The modifications at position 56 influenced the antimicrobial activity of the new derivatives; activity depended on the structure of various R groups, their ionic properties, and their steric hindrance. The activity of the new compounds did not show any significant improvement when compared with TD. The physico-chemical and antibacterial properties of the synthesized compounds are reported.