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Öğe Enantioselective resolution of racemic flurbiprofen methyl ester by lipase encapsulated mercapto calix[4]arenes capped Fe3O4 nanoparticles(SPRINGER, 2017) Yildiz, Hasan; Ozyilmaz, Elif; Bhatti, Asif Ali; Yilmaz, MustafaThis work presents the synthesis of new mercapto calix[4]arenes derivatives (4 and 5). These derivatives were capped on Fe3O4 magnetic nanoparticles and subsequently encapsulated with Candida rugosa through sol-gel method to furnish enc-4 and enc-5, respectively, to enhance catalytic activity and enantioselectivity of lipase for hydrolysis reaction of racemic flurbiprofen methyl ester. Catalytic activity and enantioselectivity of enc-4 and enc-5 were assayed at different pH and temperature conditions and it was found that the resultant encapsulated enzyme exhibited higher thermal and operational stabilities compared to the free lipase in which enc-5 showed the excellent rate of enantioselectivity (E = 176) for S-flurbiprofen better than free lipase (E = 137) at pH 7 and 35 A degrees C for 48 h. The time study shows that enantioselectivity reached the maximum value of E = 244 after 72 h. Catalytic activity of these materials was hardly affected by 20 and 23% after five usages of enc-4 and enc-5, respectively.Öğe Potential neoplastic effects of parathion-methyl on rat liver(SCIENCE PRESS, 2009) Coral, M. Nisa Unaldi; Ucman, Sonay; Yildiz, Hasan; Oztas, Haydar; Dalkilic, SemihThe mutagenic and carcinogenic effects of parathion-methyl were examined by bacterial reverse mutation assay and a long-term experiment with wistar rats. The potential mutagenic effect of parathion-methyl in Salmonella typhimurium TA100 bacterial cells was observed without rat liver S9 metabolic activation. Parathion-methyl was further investigated for pathological changes in rat pancreas and liver. The long-term rat experiments showed that parathion-methyl exposure for 3 months can cause pathological changes in rat pancreases acinar cells and pancreatic hepatocytes. Atypical acinar cell focuses (AACF) were determined in the liver and pancreas of the rats. The results from short-term Ames test and long-term rat experiments suggested that parathion-methyl would be potential carcinogenic.