Amino acid based bioanalogous polymers. Novel regular poly(ester urethane)s and poly(ester urea)s based on bis(L-phenylalanine) α,ω-alkylene diesters

Novel biodegradable regular poly(ester urethane)s 2 (η_red ≤ 0,62 dL/g) were synthesized for the first time by polycondensation of di-p-toluenesulfonic acid salts of bis(phenylalanine) α,ω-alkylene diesters 1 with di-p-nitrophenyl trimethylenedicarbonate (4) under mild conditions in organic solvents in the presence of triethylamine as acid acceptor. The first synthesis of homopoly(ester urea)s 3 (η_red ≤ 0,33 dL/g) was carried out by polycondensation of 1 with di-p-nitrophenyl carbonate (5) under the same conditions. Preliminary in vitro evaluation of specific and nonspecific hydrolysis of the polymers obtained has been brought about using potentiometric titration.