Yayınlar
- MakaleAçık Erişim2017Accumulation of phenolics in natural and micropropagated plantlets of Thymus pseudopulegioides Klokov & Des.-Shost. with their antioxidant potentials
Günaydin, Mustafa; Laghari, Abdul Hafeez; Bektas, Ersan; Sökmen, Munevver; Sökmen, Atalay
Thymus pseudopulegioides plantlets were propagated in vitro via direct organogenesis by using Murashige and Skoog (MS) media containing kinetin, thidiazuron, and 6-benzyladenine (BA) individually. Methanol extracts obtained both from plantlets and wild plants were analyzed for their total phenolics and flavonoid contents, then quantified by HPLC. The highest total phenolic (8.83 mg/g as gallic acid equivalent) and total flavonoid (0.92 mg/mL as rutin equivalent) values were from the MS media supplemented with 1.0 mg/L kinetin and 0.5 mg/L BA, respectively. The plantlets grown in those media also showed remarkable antioxidant activities with an IC50 value of 4.77 mu g/mL in DPPH and 100% inhibition in beta-carotene assays, respectively. HPLC analysis proved the production of protocatechuic, caffeic, vanillic, rosmarinic, ferulic, and o-coumaric acids and rutin. Rosmarinic acid production was predominant in natural samples (115.2 mg/100 g dry weight), while the aforesaid phenolic acids were prevalent in plantlets grown on MS media supplemented with KIN or BA at various concentrations. Rutin production was the highest (50.74 mg/100 g dry weight) in the plantlets grown on MS medium containing kinetin (1.0 mg/L). As an economically important chemical, rosmarinic acid was selected as the target chemical and a novel method was introduced to achieve its selective isolation.
- MakaleAçık Erişim2012Synthesis and antimicrobial activity of new phthalocyanine complexes and electrochemical and spectroelectrochemical behaviour of cobaltphthalocyanine
Kaya, Elif Çelenk; Karadeniz, Hülya; Koca, Atif; Kahriman, Nuran; Sökmen, Atalay
A novel phthalocyanine bearing oxygen donor atoms on the peripheral positions has been synthesised by cyclotetramerisation of (E)-4-(4- cinnamoylphenoxy) phthalonitrile and its nickel, zinc, cobalt, copper and lead derivatives prepared. The thermal stabilities of the phthalocyanine compounds have been determined and their possible biological activities (antibacterial, anticandidal and antifungal) studied. The effects of substituent on the electrochemical and in situ spectroelectrochemical behaviour of cobaltphthalocyanine have been investigated and an in situ electrocolorimetric method was applied to investigate the colour of the electrogenerated anionic and cationic forms of the complex.
- MakaleYalnız künye2011Microwave-assisted synthesis and characterization of novel symmetrical substituted 19-membered tetrathiadiaza metal-free and metallophthalocyanines and investigation of their biological activities
Nas, Asiye; Kaya, Elif Celenk; Kantekin, Halit; Sökmen, Atalay; Çakir, Volkan
This work reports on a new symmetrically substituted metal-free phthalocyanine and its transition metal complexes which were prepared by a condensation of N,N'-[propan-1,3-diilbis(tiyoetan-2,1-diil)]bis(4-methylbenzenesulfonamid) (1) and 1,2-bis(2-iodomercaptoethyl)-4,5-dicyanobenzene (2) with NiCl(2), ZnCl(2), CoCl(2), CuCl(2), and PbO salts in 2-(dimethylamino) ethanol, respectively. The phthalocyanines bearing thia and aza donor atoms at the peripheral position were characterized by IR, UV-Vis, (1)H NMR, (13)C NMR, Mass spectra, and elemental analysis data. The thermal behaviors of 4-9 were investigated by TG/DTA. Novel phthalocyanines were also investigated for enlightening their possible biological activities by employing antimicrobial (antibacterial and antifungal), antineoplastic and antioxidative assays. Of all tested, four samples exhibited antimicrobial activity against test microorganisms, among which, Branhamella catarrhalis was the most sensitive one with a MIC value around 0.312 mg/mL followed by a yeast, Candida albicans (MIC. 0.625 mg/mL). Due to their colored nature, the samples were found not to be applicable for antioxidative and antineoplastic assays. (C) 2011 Elsevier B. V. All rights reserved.
