Ülkü Dilek Uysal

Time and temperature dependent microbiological and mycotoxin (ochratoxin-A) levels in boza

This study describes the examination of microbiological tests and the determination of OTA in boza temperature and time dependently. Prior to the analysis, physicochemical properties of the boza samples such as moisture, total acidity as lactic acid, pH, protein amount and viscosity were investigated. The incidence of total aerobic bacteria (TAB), lactic acid bacteria (LAB), coliforms, E.coli, Salmonella, S. aureus, B. cereus, yeast and moulds were examined. E.coli, Salmonella, S. aureus and B. cereus were not found in all boza samples. Initially, Aspergillus fumigatus; Acremonium sp.; Geotrichum candidum and Geotrichum capitatum were identified in the samples. Certain extraction techniques such as direct injection, liquid-liquid and solid phase (SP) were tried for the OTA analysis. The most available way was found to be direct injection among them and the recovery was 70.56%+/-9.80 (13.89 RSD). OTA amounts were determined in all boza samples utilizing an isocratic HPLC analysis with an ODS column. OTA was detected in only one sample as 3.58 microg/kg and this amount is above the limits of European Commission Regulations. Time and temperature-dependent changes were investigated and insignificant variation was observed.

Validated capillary electrophoresis study for the determination of cetirizine in pharmaceutical forms

Abstract A capillary electrophoretic method for the determination of cetirizine is described in this study. The method was developed by using a running buffer consisting of 10 mM of 10% methanol with pH 8.5, employing a fused silica column with a total length of 85 cm, an effective length of 65 cm, and internal diameter of 75 µm. 28 kV were applied, which produced signals that were detected at 200 nm. Under these conditions, cetirizine and phenobarbital sodium as an internal standard appeared at 6.7 and 8.9 minutes, respectively. The limits of detection and quantification were found to be 5.45×10−6 M and 1.60×10−5 M, respectively. The repeatability and linearity of the method were validated by intra‐day and inter‐day precision. Then, the proposed method was applied to Zyrtec® tablet, syrup, and oral drop. The results indicate that the method is simple, accurate, and precise for the analysis of cetirizine.

A rapid determination of patulin using capillary zone electrophoresis and its application to analysis of apple juices.

This study describes a capillary zone electrophoretic method for the determination of patulin. An optimum run buffer was found to be 25 mM of sodium tetraborate and 10% acetonitrile (v/v) at pH 10. Optimum conditions were determined to be: an applied voltage of 25 kV (normal polarity), temperature of 25°C and injection time of 10 s at 50 mbar; the signals of patulin and phenobarbital as internal standard were detected at 276 nm. The method was highly reproducible, with relative standard deviations of 0.02-0.85 for intra-day and 0.04-0.42 for inter-day for standard patulin. Acceptable linearity [y = 0.0020C (μg/L) - 0.0680 (r = 0.9999)] was obtained over a concentration range of 0.25 to 4.99 µg/mL of patulin. The limits of detection and quantification were calculated to be 5.9 × 10(-3) and 1.79 × 10(-2) µg/mL, respectively. Recovery was 68.0%. The proposed method was applied to 21 apple juice samples purchased from different Turkish markets, and two were found to contain higher than the limits of the European Union Directive for patulin.

Validated Method for the Determination of Deflazacort by a Flow‐Injection Analysis with UV Detection: Application to Pharmaceutical Formulations

Abstract A simple, precise, accurate, and fast flow‐injection analysis (FIA) method employing UV detection is described for the determination of deflazacort (DEF) in pharmaceutical tablets. The best carrier solvent system consisted of EtOH: sodium dihydrogen phosphate (0.2 M) (20:80, v/v) (pH 6.0). Related parameters were elucidated and a flow‐rate of 1.3 mL min−1 was used and the analyte was monitored at 247 nm. In the optimum condition, the repeatability was in the range of 0.27–0.41 as intra‐day precision. The linearization was tested considering intra‐ and inter‐day experiments in the range of 1.0 × 10−5–5.0 × 10−5 M and good correlation coefficients were obtained. The limit of detection (LOD) and the limit of quantification (LOQ) were calculated to be 2.35 × 10−7 and 7.04 × 10−7 M, respectively, as inter‐day results. The proposed method was applied to the determination of DEF in pharmaceutical preparations. Conventional UV‐spectrophotometry was used as a comparison method and their results were also compared to those of the FIA technique. Insignificant differences between FIA and UV‐spectrophotometric results were observed (p < 0.05). In conclusion, the tablets provide the general official requirements, 101.3% and 102.3%, respectively. Therefore, the proposed method is suggested to the routine laboratories for the determination of DEF in tablets.

DETERMINATION OF ZEARALENONE BY THE CAPILLARY ZONE ELECTROPHORESIS-UV DETECTION AND ITS APPLICATION TO POULTRY FEED AND CEREALS

A capillary zone electrophoretic method for the determination of zearalenone is described in this study. In the separation, a run buffer consisting of 20 mM sodium tetraborate at pH 9.0 with 15% acetonitrile applying 15 kV, injecting 10 s at 50 mbar was utilized. Phenobarbital was a suitable internal standard and the signals were recorded at 254 nm. Zearalanon and internal standard appeared at 5.46 min (RSD% 0.20) and 6.35 min (RSD% 0.18), respectively. The repeatability results are in the range of 0.01–1.58 for inter-day. The linearity was investigated in the range of 5.20 × 10−7 M to 7.86 × 10−5 M ZEA and it was linear fitting to the equation of [rPN = 244803.8 C(M) −0.0348; r = 0.9999]. The LOD and LOQ were calculated to be 2.70 × 10−8 M (8.25 µg/L) and 8.17 × 10−8 M (25 µg/L), respectively. Then, the method was successfully applied to the analysis of ZEA in poultry feeds, flour of maize, grain, and certain cereal samples such as fibrous biscuit, popcorn, and rice crisp.

Determination of DNA in Certain Salvia Species by Capillary Gel Electrophoresis

This article presents a newly developed capillary gel electrophoresis (CGE) using dynamic coating with hydroxyethylcellulose methodology for the separation of fourteen standard DNA fragments and determination of RAPD-PCR products after a PCR purification clean-up procedure for certain Salvia (sage) species. The developed CGE was successfully applied to the RAPD products of ten different Turkish Salvia (sage) species (Salvia bracteata, S. candidissima, S. ceratophylla, S. dichroantha (endemic), S. forskahlei, S. fruticosa, S. sclarea, S. tomentosa, S. verticillata, and S. viridis). These medicinal plants exhibit a wide range of Turkish flora. The CGE results were compared with those by the slab gel electrophoresis (SGE). The present study offers an alternative CGE method to SGE for the effective separation and evaluation of RAPD-PCR products. This CGE has certain advantages to SGE on the viewpoint of requiring smaller amount of sample and solvent, higher resolution and speed, easier automation, higher sensitivity, and online detection. DNA analysis in Salvia species can help further understanding of their biological functions. In this study, a phylogenetic relationship was analysed by SGE. S. fruticosa and S. dichroantha are genetically the most distant species, and S. bracteata and S. fruticosa are the the most similar species.

A Validated Capillary Electrophoretic Method for the Determination of Olopatadine and Its Application to a Pharmaceutical Preparation of Eye Drops

A validated rapid and sensitive capillary zone electrophoretic method for the determination of olopatadine hydrochloride (OLO) is described. Optimum conditions were found: 20 mmol/L sodium tetraborate buffer, acetonitrile 15% (v/v), 10 mmol/L NaCl at pH 9.5, with 25 kV of applied potential, injection time of 10 s at 5 × 103 N/m2, at a wavelength of 205 nm, and fixed temperature of 30°C. The calibration curve was linear in the range of 1.13 × 10-5 mol/L (4.22 μg/mL) to 5.65 × 10-5 mol/L (21.12 μg/mL), with R = 0.9995 for interday precision. LOD and LOQ values were 1.58 × 10-6 (0.58 μg/mL) and 4.78 × 10-6 mol/L (1.75 μg/mL), respectively. Precision values were 1.10-1.97% for intraday and 1.41% for interday RSDs. Accuracy was tested by preparing a synthetic mixture whose composition was similar to the pharmaceutical preparation for Patanol. The RSDs of the recovery values (98.2%) were between 0.42 and 0.65% and the amount of OLO found was 1.09 mg/mL. The result was within the requirements of USP 31-NF 26. Therefore, this validated method is suggested for routine analysis for the determination of OLO in laboratories.

Theoretical study: Non-small cell lung cancer drugs

M wild plants commonly used in folk medicine, such as different species from the genus Lathyrus, may represent new sources of biologically active compounds. Therefore, the study of the composition and (bio)chemical behaviour of extracts from these plants may provide valuable information. Several Lathyrus species have been studied: L. aureus, L. pratensis, L. czeczottianus and L. nissolia. Extracts from these plants were analyzed by high-performance liquid chromatography with electrospray ionization mass spectrometric detection (HPLC-ESI-MSn) to determine their phenolic profile. The in vitro antioxidant activity and enzyme inhibitory evaluation were also investigated. The main phenolic compounds (flavonoids and saponins, mainly) and the antioxidant and enzyme inhibition results are here reported. The phenolic contents and the (bio)chemical properties of the analyzed extracts presented significant variations in the different Lathyrus species. However, the high number of phenolic compounds and the antioxidant and enzyme assays suggest that these plants may be further used in phytopharmaceutical or food industry applications.

Theoretical study on a newly approved pharmaceutical formulation active components-Indacaterol and Roflumilast

M wild plants commonly used in folk medicine, such as different species from the genus Lathyrus, may represent new sources of biologically active compounds. Therefore, the study of the composition and (bio)chemical behaviour of extracts from these plants may provide valuable information. Several Lathyrus species have been studied: L. aureus, L. pratensis, L. czeczottianus and L. nissolia. Extracts from these plants were analyzed by high-performance liquid chromatography with electrospray ionization mass spectrometric detection (HPLC-ESI-MSn) to determine their phenolic profile. The in vitro antioxidant activity and enzyme inhibitory evaluation were also investigated. The main phenolic compounds (flavonoids and saponins, mainly) and the antioxidant and enzyme inhibition results are here reported. The phenolic contents and the (bio)chemical properties of the analyzed extracts presented significant variations in the different Lathyrus species. However, the high number of phenolic compounds and the antioxidant and enzyme assays suggest that these plants may be further used in phytopharmaceutical or food industry applications.

Theoretical Study on the Stability, Acidity Constants and Molecular Electronic Properties of Certain o-Hydroxy Schiff Bases and their Tautomers

In the present work, certain novel o-hydroxy Schiff bases and possible tautomer forms, which were previously synthesized by our group and their structures elucidated, have been calculated by DFT/6-311g(2d,2p) in both vacuum and polar solvents and the most stable tautomeric forms have been determined. The acidity constants of the Schiff bases have been calculated with the PM6 method by MOPAC2016. HOMO-LUMO values of the studied Schiff bases were calculated with DFT/6-311g(2d,2p) and their possible molecular electronic properties were searched. The results were compared with those experimental values.