Synthesis and biodegradability of new polyesteramides containing peptide linkages

Monomers having amino acid residues at the both ends were synthesized from amino acids, adipoyl chloride, and 1,4-butanediol. Polyesteramides containi ng peptide linkages (Phe-Phe, Phe-Leu, Phe-Val, and Phe-Ala) were synthesiz ed from these monomers by using 1-ethyl-3-(3-dimethylaminopropyl) carbadiim ide hydrochloride as the coupling agent. Polymers with moderate molecular w eight (5600-7700) were obtained. These polymers were soluble in organic aci ds and polar aprotic solvents such as dimethyl sulfoxide (DMSO) and N,N-dim ethyl formamide (DMF), as well as in chloroform. The results of biodegradat ion studies indicated that all of these polyesteramides were hydrolyzed by enzymes, such as alpha -chymotrypsin, subtilisin Carlsberg, and lipase. The rate of degradation depended strongly on the nature of amino acid residues in the polymer chains reflecting the enzyme specificity. The polymers obta ined are anticipated to find agricultural or biomedical applications.