Ramazan Ceylan

Removal of sulphur from four Central Anatolian lignites by NaOH

Abstract The desulphurization of four samples of Central Anatolian lignites by treatment with aqueous NaOH was examined. NaOH concentration and temperature were the significant parameters but the extraction time had only a slight effect. Organic sulphur was not removed from three of the samples but in the other lignite 12.5 wt% of the organic sulphur was removed by treatment at 70 °C for 8 h with 20 wt/v% NaOH solution. Total sulphur contents were considerably reduced by aqueous NaOH treatment but one high-sulphur lignite was found to be more resistant to sulphur removal than the others. This lignite was treated with molten caustic at 300 °C and 450 °C with the result that the total sulphur and ash contents were reduced by 47–83 wt% and 77–91 wt% respectively.

Anthraquinone profile, antioxidant and enzyme inhibitory effect of root extracts of eight Asphodeline taxa from Turkey: can Asphodeline roots be considered as a new source of natural compounds?

Abstract Plant-based foods have become attractive for scientists and food producers. Beneficial effects related to their consumption as dietary supplements are due to the presence of natural occurring secondary metabolites. In this context, studies on these products are important for natural and safely food ingredients evaluation. The aim of this study was to evaluate root extract of eight Asphodeline species as antioxidants, enzyme inhibitors and phytochemical content. Spectrophotometric antioxidant and enzyme inhibitory assays were performed. Total phenolic and flavonoids contents as well as the chemical free-anthraquinones profiles were determined using routinely procedure (HPLC-PDA). Data show that Asphodeline roots can be considered as a new source of natural compounds and can be used as a valuable dietary supplement. Some differences related to biological activities can be inferred to other phytochemicals that can be considered in the future for their synergic or competitive activities.

Hydrogenolysis and hydrocracking of the carbonoxygen bond. 3. Thermolysis in tetralin of substituted anisoles

Abstract Mild pyrolysis and hydrogenolysis products of coal contain substantial amounts of pyrocatechol and resorcinol and their homologues whereas hydroquinone and its homologues are absent or present in only low amounts. In the present work the model compounds anisole and methyl-, methoxy- or hydroxy-substituted anisoles were studied to elucidate substituent effects on the carbon—oxygen bond cleavage in the presence of tetralin. The experiments were carried out at 618 K and 6 MPa (H 2 ). The major reaction is demethylation to the corresponding phenols. A steric effect can be seen in the ortho compounds and an electronic effect when the substituent is a strongly electron-releasing group. In compounds with oxygen substituents para to each other little or no hydroquinone can be isolated whereas the ortho and meta compounds, respectively, give pyrocatechol and resorcinol. It is suggested that the low yield or absence of hydroquinone in this work and in coal pyrolysis is due to the high reactivity of the intermediate p -hydroxyphenoxy radical, which gives rise to adducts and other compounds of high molar mass. The ortho radical is sterically hindered and the meta radical has a lower reactivity and are hence abstracting hydrogen from the hydrogen donor or coal.

Lathyrus aureus and Lathyrus pratensis: characterization of phytochemical profiles by liquid chromatography-mass spectrometry, and evaluation of their enzyme inhibitory and antioxidant activities

Different wild plants commonly used in folk medicine, such as different species from the genus Lathyrus, may represent new sources of biologically active compounds. Hence, a study of the composition and (bio)chemical behaviour of extracts from these plants may provide valuable information. To evaluate the phytochemical profile, and the enzyme inhibition and antioxidant activities of the aerial parts of L. pratensis and L. aureus, extracts from both plants were analyzed by high-performance liquid chromatography with electrospray ionization mass spectrometric detection (HPLC-ESI-MSn). The in vitro antioxidant activity (phosphomolybdenum, β-carotene bleaching, DPPH, ABTS, FRAP, CUPRAC and metal chelating) and enzyme inhibitory activity (acetyl cholinesterase, butyrylcholinesterase, tyrosinase, α-amylase and α-glucosidase) were also investigated for these Lathyrus species. Flavonoids and saponins were the main groups of compounds detected in the extracts from both plants. Generally, the methanol and water extracts presented remarkable antioxidant and enzyme inhibitory effects; all the observed results are critically discussed. The content of organic compounds and the antioxidant and enzyme assays suggest that these plants may be further used in phytopharmaceutical or food industry applications.

Traditionally Used Lathyrus Species: Phytochemical Composition, Antioxidant Activity, Enzyme Inhibitory Properties, Cytotoxic Effects, and in silico Studies of L. czeczottianus and L. nissolia

Members of the genus Lathyrus are used as food and as traditional medicines. In order to find new sources of biologically-active compounds, chemical and biological profiles of two Lathyrus species (L. czeczottianus and L. nissolia) were investigated. Chemical profiles were evaluated by HPLC-ESI-MSn, as well as by their total phenolic and flavonoid contents. In addition, antioxidant, enzyme inhibitory, and cytotoxic effects were also investigated. Antioxidant properties were tested by using different assays (DPPH, ABTS, CUPRAC, FRAP, phosphomolybdenum, and metal chelation). Cholinesterases (AChE and BChE), tyrosinase, α-amylase, and α-glucosidase were used to evaluate enzyme inhibitory effects. Moreover, vitexin (apigenin-8-C-glucoside) and 5-O-caffeoylquinic acid were further subjected to molecular docking experiments to provide insights about their interactions at molecular level with the tested enzymes. In vitro cytotoxic effects were examined against human embryonic kidney cells (HEK293) by using iCELLigence real time cell analysis system. Generally, L. czeczottianus exhibited stronger antioxidant properties than L. nissolia. However, L. nissolia had remarkable enzyme inhibitory effects against cholinesterase, amylase and glucosidase. HPLC-ESI-MSn analysis revealed that flavonoids were major components in these extracts. On the basis of these results, Lathyrus extracts were rich in biologically active components; thus, these species could be utilized to design new phytopharmaceutical and nutraceutical formulations.

Changes in Coal Composition during Air Oxidation at Moderate Temperature

Abstract In this work, under atmospheric pressure and moderate temperature for various periods, e.g., 30, 45, 90, and 135 days, the air oxidation of two Central Anatolian lignites were examined. The structural changes of the lignite samples were observed by analyzing the amount of phenolic hydroxyl carboxyl, and peroxide of the samples oxidized and by comparing the IR spectra of the lignites, both original and oxidized. It was concluded that most of the phenolic structures of the lignites were oxidized into quinonoid structures during the oxidation process.

GC-MS analysis and in vitro antioxidant and enzyme inhibitory activities of essential oil from aerial parts of endemic Thymus spathulifolius Hausskn. et Velen

Abstract We investigated the antioxidant and enzyme inhibitory activities and chemical composition of the hydro-distilled essential oil (0.35% yield) from aerial parts of Thymus spathulifolius. Antioxidant capacity of the oil was assessed by different methods including free radical scavenging (DPPH and ABTS), reducing power (FRAP and CUPRAC) and phosphomolybdenum assay. Inhibitory activities were analyzed against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-amylase, α-glucosidase, and tyrosinase. Twenty-one constituents were identified representing 97.2% of the total oil with thymol (50.5%), borneol (16.7%) and carvacrol (7.7%) as the major components. The essential oil exhibited good antioxidant activity with IC50 values of 3.82 and 0.22 mg/mL determined by free radical scavenging DPPH and ABTS, respectively. EC50 values of FRAP and CUPRAC were found to be 0.12 and 0.34 mg/mL, respectively. The results of the present study support the uses of T. spathulifolius essential oil as a source of natural antioxidants and bioactivities for functional foods and phytomedicines.

PHYTOCHEMICAL CHARACTERIZATION OF AN ENDEMIC PLANT USED AS FOODSTUFF IN TURKEY: CENTAUREA URVILLEI SUBSP. STEPPOSA AND ITS ANTIOXIDANT PROP ERTIES

This study was focuse d on the analysis of the phenolic content, fatty acid composition, volatile compounds and antioxidant activity of methanol extract from Centaurea urvillei subsp. stepposa . The antioxidant capacity were detected as 43.35 mg TE s /g , 52.18 mg TE s /g and 98. 78 m g TE s /g for DPPH, FRAP and CUPRAC , respectively . C hlorogenic acid and apigenin were the major phenolic components in the extract. Linoleic acid (49.54 %) was the predominant fatty acid in the oil . 1, 3 - c yclooctadiene (25.08 %) was major components in the e ssential oil. The study concluded that Centaurea urvillei subsp. stepposa can be used as a source of natural antioxidants for food and pharmacological industry.

Identification of phenolic profiles, fatty acid compositions, antioxidant activities, and enzyme inhibition effects of seven wheat cultivars grown in Turkey: A phytochemical approach for their nutritional value

ABSTRACT In the present article, seven wheat cultivars (Ahmetaga, Bezostaya, Dagdas-94, Ekiz, Karahan-99, Konya-2002, and Tosunbey) grown in Turkey were compared for their phytochemical composition, antioxidant, and enzyme inhibitory activities. Antioxidant capacities and enzyme inhibitory effects were investigated with colorimetric methods. Total phenolic content ranged from 40.71 to 86.34 mg of gallic acid equivalent/100 g wheat grain. Tosunbey (92 mg Trolox equivalent/100 g wheat grain) and Ahmetaga (114.56 mg Trolox equivalent/100 g wheat grain) cultivars exhibited strong 2,2 azino-bis (3-ethylbenzothiazloine-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activities. As compared to other wheat cultivars, Tosunbey cultivar had remarkable both antioxidant and enzyme inhibitory effects with the highest level of phenolics. Ferulic acid, chlorogenic acid, and apigenin were the major phenolics in extracts tested. This study suggested that an increased intake of wheat derived products could represent an effective strategy for the management of oxidative stress related chronic and degenerative diseases such as Alzheimers and diabetes mellitus.

Essential Oil Composition of an Uninvestigated Centaurea Species from Turkey: Centaurea patula DC.

Abstract Centaurea patula is widely distributed in the Central Anatolia Region of Turkey. The essential oil of C. patula was obtained by hydrodistillation and analyzed by GC-FID and GC-MS techniques. Twenty-one components were identified representing 86.4% of the oil. Spathulenol (14.6%), n-hexadecanoic acid (13.4%), 1-pentadecene (13.1%) and phytol (12.4%) were found to be the major components in this oil. This work is the first report on the chemical composition of the essential oil of C. patula. The results could be valuable for the Centaurea genus in terms of essential oil information’s.