Synthesis, characterization, and degradation of a novel L‐tyrosine‐derived polycarbonate for potential biomaterial applications

Abstract

A novel class of pseudo-poly(amino acid)s was synthesized with a cyclic dipeptide as new diphenole. Nonpeptide bonds alternating with a peptide bond structure were introduced into the backbone of the pseudopoly(amino acid)s. The cyclic dipeptide in this study was obtained from natural L-tyrosine. L-Tyrosine is a major nutrient amino acid with a phenolic hydroxyl group, so a polycarbonate derived from the cyclic dipeptide should possess more optimum mechanical properties, bioactivity, and biocompatibility. The hydrolytic specimen of the resulting polycarbonate was prepared by a modified solvent evaporation process. Under strongly alkaline conditions, degradation testing was performed. The tyrosinederived polycarbonate possessed a low glass-transition temperature value and a high thermal decomposition temperature value, which formed a broad mean thermal processing range. The most important results of our study were the effects of the polycarbonate degradation on the local pH values, which were smaller than those of other biodegradable polymers [e.g., poly(lactic acid), poly(glycolic acid), and poly(lactic glycolic acid)]. The synthesized polymer and cyclic dipeptide were characterized with Fourier transform infrared, 13 C-NMR, and 1 H-NMR spectroscopy to determine their chemical structures; by differential scanning calorimetry and thermogravimetric analysis to determine the thermal properties of the polymer; by gel permeation chromatography to determine the polymer's molecular weight; and by X-ray diffraction to determine the polymer's morphology.

Bio-based polycarbonate from limonene oxide and CO2 with high molecular weight, excellent thermal resistance, hardness and transparency

“…2 Additionally, both monomers are petro-based compounds and, recently, efforts have been made to replace them, at least partially, with biobased diols, e.g. isosorbide derived from carbohydrate, 3,4 L-tyrosyine 5 or terpene derivatives. 6 An alternative route to the synthesis of PCs is the reaction of epoxides with CO 2 .…”

Total Synthesis of Mycocyclosin

“…In pursuit of a synthetic route to mycocyclosin 1 , we envisaged a biomimetic approach through initial diketopiperazine synthesis followed by oxidative phenolic coupling. Cyclodityrosine has been prepared by condensation of l -tyrosine in ethylene glycol at high temperature; however, this method has been shown to cause epimerization, resulting in mixtures of stereoisomers . Accordingly, cyclo( l -Tyr– l -Tyr) 3 was prepared by a stepwise method .…”

Mechanical properties of sol–gel coatings on polycarbonate: a review

“…The latter occurring in the longer term, polycarbonate mechanical enhancement is more challenging to further increase its durability. In this way, two solutions can be investigated: a protective coating deposit or a bulk modification [2,3]. This review is only focused on the first solution and more precisely on silica-based coatings obtained by the sol-gel process, allowing fulfilling all the required criteria (in terms of implementation facility and performances).…”