Synthesis and characterizations of dipeptide derivative of gentamicin

Abstract

The target derivative is gentamicin linked with L-Val-L-Ala by an ester linkage. It was synthesized by esterification method, which included the reaction of hydroxyl group on (carbon No.5) of gentamicin with the acid chloride of the corresponding dipeptide. The preparation of new derivative of gentamicin involved protection of the primary and secondary amino groups of gentamicin, by ethylchloroformate (ECF) to give N-carbomethoxy gentamicin which was used for further chemical synthesis involving the free hydroxyl groups. The prepared dipeptide (L-Val-L-Ala) by conventional solution method in the presence of DCC & HOBt then reacted with thionyl chloride to prepare acid chloride of dipeptides, then after, linked by ester linkage to N-protection gentamicin in present pyridine as base, finally deprotection the amino group of synthesized compound by using trifluoroacetic acid (TFA) in the presence anisole. The characterization of the titled compound was performed utilizing FTIR spectroscopy, CHNO elemental analysis, and by measurements of their physical properties.