No abstract

7-Hydroxyflavones (apigenin and hispidulin) exerted significant XO inhibitory effect with IC50 values of 0.99 ± 0.33 μM and 4.88 ± 1.21 μM, respectively. Therefore, these compounds are responsible for the XO-inhibitory effect of the extract. The free radical scavenging activity of the isolated flavonoids was determined by DPPH assay, and it was stated that none of the compounds have substantial antioxidant activity, therefore the reduced generation of reactive oxygen species may be the consequence only of XO inhibition.

Abstract:In this study, the essential oil of Centaurea pichleri ssp. pichleri was obtained by hydrodistillation using a Clevenger-type apparatus. GC and GC/MS analyzes of the essential oil from Centaurea pichleri ssp. pichleri were determined the identification of 48 components representing 86.9% of the oil. With this analysis, the major component was found as hexadecanoic acid (31.4%). Subsequent to this component, other major components were caryophyllene oxide (6.4%), spathulenol (6.2%) and dodecanoic acid (4.5%). In addition to this, fatty acid methyl esters (FAMEs) from Centaurea pichleri ssp. pichleri were prepared for analyzes of fatty acids. By this test the amount of saturated fatty acid (SFA) was found as 47.79% with major fatty acid was stearic acid (18.64%). The amount of monounsaturated fatty acid (MUFA) was found as 16.88% with major fatty acid was oleic acid (14.20%). The amount of polyunsaturated fatty acid (PUFA) was found as 21.29% with major fatty acid was linoleic acid (15.20%). The results from this work were compared with the previous works in terms of essential oils and fatty acids.

A green synthesis method of silver nanoparticles (AgNPs) usingCentaurea virgataLam. extract and the isolated compound eupatorin was investigated in this study. Ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM)/energy-dispersive X-ray (EDX) spectroscopy, thermal gravimetric analysis, X-ray diffraction analysis and zeta potential were used for characterization of AgNPs. The UV-Vis spectrum exhibited a characteristic absorption band at 420 nm for monodisperse nanoparticles. FTIR measurements also proved the formation. X-ray diffraction patterns showed peaks at (110) and (112), which are characteristic for hexagonal crystals and also showed peaks at (111), (200) and (240), which are characteristic for orthorhombic crystals. The TEM images of AgNPs show that the morphology of AgNPs was predominantly spherical. Obtained AgNPs were highly stable according to the zeta potential values. The nitric oxide scavenging activity, which is also related to anticancer activity, of AgNPs was evaluated. It can be concluded thatC. virgataLam. extract and eupatorin can be used as a reducing agent for potential antioxidant AgNP formation.

The aim of this study is to determine the fatty acid compositions and antioxidant activities of three Centaurea species as Centaurea iberica, C. urvillei ssp. hayekiana, and C. urvillei ssp. nimrodis and compare them with each other. As a result of fatty acid determination by GC MS method, oleic acid and linoleic acid were found as the main fatty acids in these Centaurea species. Polyunsaturated fatty acids (PUFAs) were determined at 58.66%, 46.98%, 62.22% in C. iberica, C. urvillei ssp. hayekiana and C. urvillei ssp. nimrodis, respectively. Antioxidant activities of methanolic extracts of three Centaurea species were evaluated by DPPH, ABTS and CUPRAC assays. The methanol extract of C. urvillei ssp hayekiana showed the highest antioxidant activity in direct proportion to the total amount of phenolic and flavonoid substances. The fact that the antioxidant activities of these three species and fatty acid analyzes have not been compared in previous studies is important in that this study is the first.

AbstractASP was used to synthesize FeNPA. They were characterized by UV-vis spectroscopy, FT-IR, TEM, SEM, XRD and ZP. The aim of this study was to evaluate in vitro cytotoxic activity and antioxidant acitivities of FeNPA and ASP. The antioxidant properties were evaluated using DPPH, ABTS+ and H2O2 assays. FeNPA had higher antioxidant activity comparing to ASP according to DPPH (IC50: 3.48 μg/mL) and ABTS+ (60.52%) assays. Anti-cancer activities of FeNPA and ASP were investigated in breast cancer, melanoma and control cell lines. FeNPA was more cytotoxic than ASP in MCF-7, MeWo, CHL-1, and HEL 299 cells. FeNPA had shown that mitochondria induce apoptosis through stress in MDA-MB-231, and cells MeWo. ASP also induced apoptosis 2.23-fold in MCF-7 cells. Progesterone receptor gene expression showed a 10-fold increase in a hormone-dependent MCF-7 cell line in ASP, and FeNPA treatment. Expressions of BCL6, CXCL12, DNAJC15, RB1 and TPM1 in melanoma cancer cell lines were significantly increased in ASP and FeNPA administration. It had been shown that FeNPA regulates gene expressions that may be considered important in terms of prognosis in breast cancer and melanoma cell lines and it is suggested that gene expressions regulated by FeNPA are also evaluated in animal models in vivo.

Centaurea is a widespread genus from Asteraceae family in Turkey. There are plenty of researches about fatty acid and essential oil profiles of Centaurea species. Essential oils were obtained using a Clevenger apparatus by hydrodistillation from aerial part of the plant. The essential oil composition of the plant was identified by GC-MS using FID detector. 31 compounds representing 91.5% were identified. Hexadecanoic acid (50.2%) and tetradecanoic acid(10.1%) were found to be the major compounds. For fatty acids, fatty acid methyl esters (FAMEs) were prepared. The fatty acid compositions were analyzed by GC. Saturated fatty acids (SFAs) were totally 25.05%, monounsaturated fatty acids (MUFAs) were 19.60% and polyunsaturated fatty acids were 19.86%. The major compounds were found as oleic acid (18.54%), linoleic acid (10.07%), palmitic acid (8.28%), stearic acid (6.82%) and ℽ-linoleic acid (6.75%).

In this study, the fatty acid compositions of Anthemis aciphylla var. aciphylla, Anthemis pseudocotula, Anthemis macrotis and Anthemis coelopoda var. bourgaei growing in İzmir, Turkey were determined. The fatty acid composition was analyzed using gas chromatography. Generally, C 4:0 butyric acid, C 18:2 linoleic acid and C 6:0 caproic acid were found to be the major fatty acids in all species.