2016-06-01, Tekkeli, S. E. Kepekci, Kiziltas, M. V., Dincel, DEMET, ERKOC, R., Topcu, GÜLAÇTI, TEKKELİ, ŞERİFE EVRİM, DİNCEL, DEMET, TOPÇU, GÜLAÇTI

Introduction: In patients with chronic kidney disease (CKD), uremic toxins accumulate in blood and cannot be excreted with urine. Accumulation of these toxins has negative effects on many body functions. Because of the importance of these toxins, we developed and validated a simple, sensitive, accurate, and precise method for the determination of two main uremic toxins:phenol and p-cresol in human urine. Materials and methods:Separation of these analytes in urine samples was achieved by reverse-phase high-performance liquid chromatography (RP-HPLC) with a C18 column at 35 degrees C using the mobile phase of methanol-water (65:35) at a flow rate of 1.4 mL min(-1). Fluorimetric detection was used at 284 nm for excitation and 310 nm for emission. Results:The method is linear over the range of 1.5-35 ng mL(-1) and 1-45 ng mL(-1) for phenol and p-cresol, respectively. The method was applied to urine samples from 10 healthy subjects and 10 chronic kidney disease patients. Conclusions:This assay appears to be useful in routine analysis of clinical samples for simultaneous determination of phenol and p-cresol levels in urine.

2013-01-01, Dincel, DEMET, Hatipoglu, Seda Damla, GOREN, AHMET CEYHAN, Topcu, Gulacti, DİNCEL, DEMET, GÖREN, AHMET CEYHAN, TOPÇU, GÜLAÇTI

The petroleum ether extract of Heracleum platytaenium afforded 8 furocoumarins (psoralen, bergapten, xanthotoxin, pimpinellin, isopimpinellin, sphondin, byakangelicin, and heraclenol) and the methanol extract of H. platytaenium gave only 1 glycosylated dihydrofurocoumarin, apterin. In addition, stigmasterol was also obtained from petroleum ether extract. Structure identification of the isolated compounds has been achieved by using spectroscopic methods, namely 1D and 2D NMR experiments and mass spectral analyses. The antioxidant activity of the extracts and pure compounds was investigated by 2 methods, including DPPH free radical scavenging activity and lipid peroxidation inhibitory activity by beta-carotene-linoleic acid assays. The anticholinesterase activity of petroleum ether and methanol extracts of the plant and the isolated furocoumarins was investigated against acetylcholinesterase and butyrylcholinesterase enzymes by the Ellman method in vitro.