950730-96-8Relevant academic research and scientific papers
Synthesis of biodegradable chiral poly(ester-imide)s derived from valine-, leucine- and tyrosine-containing monomers
Mallakpour, Shadpour,Asadi, Parvin,Sabzalian, Mohammad R.
, p. 1215 - 1222 (2011)
The present demand for a drastic reduction in environmental pollution is extended to qualitative change in the approach to development of biodegradable polymers. The aim of this article is to focus on the synthesis of biodegradable optically active poly(ester-imide)s (PEI)s, which compose of different amino acids in the main chain as well as in the side chain. These polymers were synthesized by polycondensation of diacid monomers such as 5-(2-phthalimidyl-3- methyl butanoylamino) isophthalic acid (1), 5-(4-methyl-2-phthalimidyl pentanoylamino)isophthalic acid (2) with N,N0-(pyromellitoyl)-bis-L-tyrosine dimethyl ester (3) as a phenolic diol. The direct polycondensation reaction was carried out in a system of tosyl chloride, pyridine and N,N-dimethylformamide as a condensing agent under conventional heating conditions. The optically active PEIs were obtained in good yield and moderate inherent viscosity. The synthesized polymers were characterized by means of FT-IR, 1H-NMR, elemental and thermo gravimetric analysis techniques. In addition, in vitro toxicity and soil burial test were employed for assessing the sensitivity of these compounds to microbial degradation. To this purpose, biodegradability behavior of the monomers and polymers were investigated in culture media and soil condition. The results of this study revealed that synthesized monomers and their derived polymers are biologically active and probably microbiologically biodegradable. Springer-Verlag 2010.
Antioxidant activity of new aramide nanoparticles containing redox-active N-phthaloyl valine moieties in the hepatic cytochrome P450 system in male rats
Hassan, Hammed H.A.M.,El-Banna, Sabah G.,Elhusseiny, Amel F.,Mansour, El-Sayed M.E.
, p. 8255 - 8275 (2012/10/18)
We report the synthesis of aramide nanoparticles containing a chiral N-phthaloyl valine moiety and their antioxidant activities on hepatic contents of cytochrome P450, amidopyrene N-demethylase, aniline-4-hyroxylase and induced the hepatic content of cytochrome b5 and nicotinamide adenine dinucleotide phosphate (NADPH) cytochrome C-reductase. Polymers were obtained as well-separated spherical nanoparticles while highly aggregated particles via H-bonding organization of the aramide-containing pyridine led to a thin layer formation. The effects of the nanoparticles and CCl4 on enzyme activities and thiobarbituric acid reactive substances (TBARS) levels of male rat liver were studied. Pretreatments of rats with the polyamides prior to the administration of CCl4 decreased the hepatic content of the tested enzymes. Doses reduced the toxic effects exerted by (CCl3) upon the liver through inhibition of the cytochrome P450 system. Inhibition of such metabolizing enzymes could reduce the carcinogenic effects of chemical carcinogens.
