Preparation and characterization of biologically nanorods shaped structure pseudo-poly(amino-acid)s containing phthalimide moiety condensed from essential L- amino acids

A class of nanostructured biodegradable poly(ester-imide-sulfonamide)s as pseudo-poly(aminoacid)s (PAA)s bearing natural amino acids in the main chain was synthesized. In this investigation,N,N-(Pyromelitoylimidyl)-bis-(4-hydroxy tyrosine dimethyl ester benzyl sulfonamide) (PHTBS) asa biologically diphenol and N,N -(pyromellitoyl)-bis-(L-amino acid) such as L-phenylalanine, Lleucine,S-valine, L-alanine and L-methionine were used for direct polyesterification by tosylchloride/pyridine/ N,N′-dimethylformamide system as a condensing agent. The novel PHTBS andobtained PAAs were characterized with FTIR, 13C-NMR, 1H-NMR spectroscopy, X-ray diffraction(XRD), field emission scanning electron microscopy and elemental analysis. Differential scanningcalorimetry and thermogravimetric analysis were used to determine the thermal properties of thepolymers. X-ray diffractograms of polymers show sharpness peaks with an amorphous backgroundwhich indicate the crystalline structures in the backbone of polymer. This absorption was confirmedwith SEM analysis which show nanorods shaped of obtained polymers. On the basis ofthermogravimetric analysis data, such PAAs are thermally stable and can be classified as selfextinguishingpolymers. The obtained PAAs possessed more bioactivity, moderate thermal stabilityand high solubility in common organic solvents. Furthermore soil dehydrogenase activity of thePHTBS and the obtained PAAs assay showed that the synthetic materials are biologically activeand then could be classified as bioactive and biodegradable compounds.

Keywords:

Nanorods-shaped structure polymers , Tyrosine , poly(amino acid)s , dehydrogenase activity