Synthesis, characterization and in vitro antimicrobial and biodegradability study of pseudo-poly(amino acid)s derived from N,N′-(pyromellitoyl)-bis-l-tyrosine dimethyl ester as a chiral bioactive diphenolic monomer

In this investigation N,N′-(pyromellitoyl)-bis-l-tyrosine dimethyl ester (7) as a chiral bioactive diphenolic monomer was prepared in three steps. The aim of this work was to obtain novel optically and biologically active pseudo-poly(amino acid)s (PAA)s that are more soluble in common organic solvents while maintaining their high thermal stability. Thus, several new, highly soluble, thermally stable, optically active and biodegradable PAAs containing different amino acid moieties in the main chain were prepared with moderate molecular weights via direct polycondensation using tosyl chloride, pyridine and N,N′-dimethylformamide as a condensing agent. The resulting novel polymers were characterized with FT-IR, 1H-NMR, elemental and thermogravimetric analysis techniques. In addition, in vitro toxicity and biodegradability behavior of the diphenolic monomer 7, different synthetic diacids (3a–3e) and obtained PAAs, which were investigated in culture media, showed that the synthesized compounds and polymers derived from them are biologically active and biodegradable under a natural environment.