Abdulselam Ertas

Simultaneous determination of seven phthalic acid esters in beverages using ultrasound and vortex‐assisted dispersive liquid–liquid microextraction followed by high‐performance liquid chromatography

A sensitive, rapid, and simple high-performance liquid chromatography with UV detection method was developed for the simultaneous determination of seven phthalic acid esters (dimethyl phthalate, dipropyl phthalate, di-n-butyl phthalate, benzyl butyl phthalate, dicyclohexyl phthalate, di-(2-ethylhexyl) phthalate, and di-n-octyl phthalate) in several kinds of beverage samples. Ultrasound and vortex-assisted dispersive liquid-liquid microextraction method was used. The separation was performed using an Intersil ODS-3 column (C18 , 250 × 4.6 mm, 5.0 μm) and a gradient elution with a mobile phase consisting of MeOH/ACN (50:50) and 0.2 M KH2 PO4 buffer. Analytes were detected by a UV detector at 230 nm. The developed method was validated in terms of linearity, limit of detection, limit of quantification, repeatability, accuracy, and recovery. Calibration equations and correlation coefficients (> 0.99) were calculated by least squares method with weighting factor. The limit of detection and quantification were in the range of 0.019-0.208 and 0.072-0.483 μg/L. The repeatability and intermediate precision were determined in terms of relative standard deviation to be within 0.03-3.93 and 0.02-4.74%, respectively. The accuracy was found to be in the range of -14.55 to 15.57% in terms of relative error. Seventeen different beverage samples in plastic bottles were successfully analyzed, and ten of them were found to be contaminated by different phthalic acid esters.

Chemical profile by LC–MS/MS, GC/MS and antioxidant activities of the essential oils and crude extracts of two Euphorbia species

In this study, it was aimed to investigate the chemical composition and antioxidant activities of two Euphorbia species. The major component of the fatty acid compositions obtained from the petroleum ether extracts was identified as palmitic acid for Euphorbia gaillardotii and Euphorbia macroclada. The main constituents of the essential oils were identified as arachidic acid for E. gaillardotii and tetratetracontane for E. macroclada. Among the 27 studied compounds, hesperidin, rutin, hyperoside and quinic, malic, gallic and tannic acids were found to be the most abundant compounds in the two Euphorbia species. The methanol extracts of E. gaillardotii and E. macroclada showed strong antioxidant activity in all tested methods. Particularly, IC50 values of E. macroclada methanol extract that was the richest in terms of total phenolic-flavonoid contents were found to be lower than α-tocopherol and butylated hydroxytoluene in β-carotene bleaching, 2,2-diphenyl-1-picrylhydrazyl free and ABTS cation radical scavenging methods.

Chemical Profile and Biological Activities of Two Edible Plants: Chemical Investigation and Quantitative Analysis Using Liquid Chromatography Tandem Mass Spectrometry and Gas Chromatography Mass Spectrometry

The objectives of this study were to define the phenolic and fatty acid profiles, anticholinesterase, antioxidant, antimicrobial activities, and total phenolic-flavonoid contents of Lycopsis orientalis and Tragopogon latifolius var. angustifolius which have been used as food source and food supplement in Anatolia and have never been examined before. Rosmarinic and quinic acids (21.11 and 11.46 mg g–1 extract, respectively) were found to be the most abundant constituents in L. orientalis and T. latifolius var. angustifolius among the studied 27 compounds by liquid chromatography tandem mass spectrometry. In the fatty acid compositions of L. orientalis and T. latifolius var. angustifolius that were determined by gas chromatography mass spectrometry, oleic (29.1%) and palmitic (28.7%) acids were identified as the major components, respectively. The high antioxidant activity of the methanol extract of L. orientalis shows parallelism to its rosmarinic acid content. Besides, this extract showed medium anticholinesterase activity. The results of the present study proves that the L. orientalis might also be used as a food source due to its high phenolic acid content and strong antioxidant property.

Chemical Composition of The Essential Oils of Three Centaurea Species Growing Wild in Anatolia and Their Anticholinesterase Activities

Abstract This report represents the first study on the chemical composition of essential oil of endemic Centaurea lycopifolia. This report also represents the first study on the anticholinesterase activity of essential oils of C. lycopifolia, C. balsamita and C. iberica. Essential oils were obtained using a Clevenger apparatus by hydrodistillation from the whole parts of C. lycopifolia, C. balsamita and C. iberica. The essential oils composition of the plants were determined by GC-FID and GC-MS (gas chromatograph/mass spectrometry) analysis. The major component of the essential oils was identified as caryophyllene oxide (9.7 %) and spathulenol (7.3 %) for C. lycopifolia, α-selinene (8.5 %) and hexatriacontane (8.3 %) for C. balsamita and arachidic acid (25.3 %) and hexadecanoic acid (5.9 %) for C. iberica. The essential oils of three Centaurea species indicated moderate inhibitory effect against butyrylcholinesterase and acetylcholinesterase enzyme, at 200 µg/mL.

Essential oil compositions and anticholinesterase activities of two edible plants Tragopogon latifolius var. angustifolius and Lycopsis orientalis.

This is the first report in the literature on essential oil compositions of Tragopogon latifolius var. angustifolius and Lycopsis orientalis which were analysed by using GC-FID and GC–MS techniques. The main constituents of T. latifolius var. angustifolius were identified as α-selinene (10.5%), 2,5-di-tert octyl-p-benzoquinone (9.5%) and valencene (7.0%); however, the main components of L. orientalis were identified as heptacosane (10.5%), τ-muurolene (9.6%) and tetratetracontane (9.4%). The essential oils of T. latifolius var. angustifolius and L. orientalis species exhibited moderate inhibitory activity against acetyl- and butyryl-cholinesterase enzymes at 200 μg/mL.

A comprehensive LC–MS/MS method validation for the quantitative investigation of 37 fingerprint phytochemicals in Achillea species: A detailed examination of A. coarctata and A. monocephala

HIGHLIGHTSA comprehensive LC–MS/MS method validation to quantify 37 phytochemicals in plants.The developed method is applicable to all plant species as well as Achillea.The studied species might be a source for chlorogenic acid, rutin and apigenin.A. monocephala; promising species in terms of antioxidant and cytotoxic activities. ABSTRACT The current study aims to optimize and validate a comprehensive LC–MS/MS method for the quantification of 37 phytochemicals (15 phenolic acids, 17 flavonoids, 3 non‐phenolic organic acids, 1 phenolic aldehyde and 1 benzopyrene) in Achillea species. Though Achillea species were chosen as real life samples, the current method is applicable to a wide range of plant species. The developed method was fully validated in terms of linearity, accuracy (recovery), inter‐day and intra‐day precision (repeatability), limits of detection and quantification (LOD/LOQ) and relative standard uncertainty (U% at 95% confidence level (k=2)). Reversed‐phase ultrahigh performance liquid chromatography was optimized to achive optimum separation for 37 phytochemical compounds and to overcome the suppression effects. MS detection was performed using a triple quadrupole mass spectrometer and negative or positive ionization modes were optimized for each analyte. Multiple reaction monitoring (MRM) was used to quantify the analytes, related molecular ions and transition ions were optimized. Phytochemical screening of ethanol and methanol‐chloroform extracts of root and aerial parts of A. coarctata and A. monocephala were performed by using the developed and validated LC–MS/MS method. Root and aerial parts of both species have considerable amounts of certain phenolic‐nonphenolic acids (quinic, malic, fumaric, chlorogenic and vanillic acids) and flavonoids (rutin, hesperidin, isoquercitrin, apigetrin, luteolin, apigenin). Additionally, total phenolic and flavonoid amounts, antioxidant (DPPH free radical scavenging assay, ABTS radical cation decolorization assay, &bgr;‐carotene lipid peroxidation test system and CUPRAC cupper reduction capacity methods), anticholinesterase, tyrosinase, urease inhibition and cytotoxic activities (on HeLa (Human Cervical Carcinoma Cell Line) of A. coarctata and A. monocephala were also investigated. It has been determined that the studied Achillea species, that are rich in total phenolic‐flavonoid and chlorogenic acid contents, have high antioxidant and cytotoxic potential at the same time. According to the results of LC–MS/MS, antioxidant and cytotoxic activity studies, after detailed chemical investigation and toxicity studies on these species, A. coarctata and A. monocephala may be promoted as promising sources of natural agents and used for the development of nutraceuticals or functional food ingredients in future.

Chemical profile and biological activities of Veronica thymoides subsp. pseudocinerea

Abstract Context: In Turkey, Veronica species (Plantaginaceae) have been used as a diuretic and for wound healing in traditional medicine. Objective: To examine the fatty acid and essential oil profiles, the antioxidant, anticholinesterase, antimicrobial, and DNA damage effects of Veronica thymoides P.H. Davis subsp. pseudocinerea M.A. Fischer as a potential source of natural active compounds. Materials and methods: GC/MS was used to analyze essential oil and fatty acid obtained from whole plant. The antioxidant activity was evaluated by the β-carotene-linoleic acid test system, DPPH-free and ABTS cation radicals scavenging, and cupric reducing antioxidant capacity assays. The anticholinesterase and antimicrobial activities were determined by Ellman and broth macrodillution methods, respectively. The effect of the methanol extract on DNA cleavage was investigated. Results: Hexatriacontene (21.0%) was found to be the main constituent in essential oil, and linoleic acid (25.2%) and palmitic acid (20.6%) in fatty acid. Methanol extract demonstrated the best IC50 values in lipid peroxidation (49.81 ± 0.31 µg/ml) and DPPH-free radical scavenging activity (15.32 ± 0.17 µg/ml). Methanol and water extracts possessed strong ABTS cation radical scavenging activity with IC50 values 9.15 ± 0.28 and 8.90 ± 0.14 µg/ml, respectively. The acetone extract exhibited moderate butyrylcholinesterase inhibitory activity. The highest antimicrobial activity was determined in methanol extract against Escherichia coli with 31.25 µg/ml MIC value. Inhibition of methanol extract on plasmid DNA cleavage by OH radicals was found to be 93.32% at 500 µg/ml. Conclusion: The methanol extract having strong antioxidant and DNA damage effects could be investigated phytochemically to find natural active compounds.

Characterization of the Chemical Profile of Euphorbia Species from Turkey by Gas Chromatography–Mass Spectrometry (GC-MS), Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS), and Liquid Chromatography–Ion Trap–Time-of-Flight–Mass Spectrometry (LC-IT-TOF-MS) and Chemometric Analysis†

Abstract The Euphorbiaceae family comprises of about 300 genera and 5000 species primarily distributed in America and tropical Africa. The Euphorbia genus is represented by 105 species and locally named as “Sütleğen” and “Xaşîl” in Turkey. The present study aimed to determine the chemical constituents of E. aleppica, E. eriophora, E. macroclada, E. grisophylla, E. seguieriana subsp. seguieriana, E. craspedia, E. denticulata, E. falcata, and E. fistulosa, and classify them by utilizing the chemometric techniques of principal component analysis (PCA) and hierarchical cluster analysis (HCA). Linoleic acid, 17-tetratriacontane, palmitic acid, and hexatriacontane were the major fatty acids from the gas chromatography–mass spectrometry (GC/MS) analyses. Characterization of 268 constituents of the studied species was achieved by liquid chromatography–ion trap–time-of-flight–mass spectrometry (LC-IT-TOF-MS). Furthermore, a new liquid chromatography–tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous quantitative determination of 11 compounds (quinic acid, protocatechuic acid, rutin, hesperidin, eugenol, p-coumaric acid, piceatannol, scopoletin, dl-kavain, chrysophanic acid, and resiniferatoxin) in these species. The developed method was validated for the linearity, limit of detection, limit of quantification, repeatability, and recovery.

Trace Elemental Analysis of Allium Species by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) with Multivariate Chemometrics

ABSTRACT Aerial parts and roots of the 12 Allium species collected from five localities of Turkey were studied for trace elements (Ag, As, Cd, Co, Cr, Cu, Ni, Pb, Se, Tl, V, and Zn) using inductively coupled plasma mass spectrometry (ICP-MS). A tomato leaves certified reference material was used to characterize the accuracy and precision of the analysis. Each Allium species contained Se (315–2740 µg/kg), Tl (2.75–71 µg/kg), V (77–6790 µg/kg), and Zn (3.73–26.6 mg/kg) which can meet the necessary daily intake of these minerals. In addition, chemometric analyses were performed using correlation analysis, principal component analysis, and hierarchical cluster analysis to determine the association of 12 trace elements in the Allium species. Using chemometrics, the distribution of elements between aerial parts and roots, and geographic collection localities of Allium species were also examined. This study is important the consumers because of the wide consumption of Allium species. This report is the first detailed characterization of the metal content of Allium species.