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Antioxidant properties of methanolic extract of 'Veronica multifida' and DFT and HF analyses of its the major flavonoid component
(Elsevier, 2019) Koc, Emre; Ungordu, Ayhan; Candan, Ferda
The experimental part of this study, investigated the effects of a methanolic extract of Veronica multifida on total phenolic and flavonoid content, antioxidant capacities; and DPPH scavenging activity. The methanol extract of V. multifida showed an equivalent of phenolic content of 196.67 mg gallic acid per gram dry weight, flavonoid content of 206.17 mg quercetin per gram dry weight and total antioxidant capacities of 134.41 mM alpha-tocopherol acetate per gram dry weight. Additionally, the amount of extract supplying 50% inhibition of DPPH was assayed as 66.65 mg L-1. The V. multifida plant extract to be used in the study was reported to contain luteolin as its main flavonoid component. The luteolin content of 0.2-0.5 mu g g(-1) was reported to be within the normal concentration range. Additionally, the antioxidant properties of luteolin were theoretically examined and compared to butylated hydroxytoluene and curcumin, which are respectively synthetic and natural antioxidants. The density functional theory (DFT) and Hartree-Fock methods were used in all calculations. The most stable structures of molecules were determined by using the B3LYP functional with the 6-311G(d,p) basis set. The theoretical methods showed that the antioxidant properties of pure luteolin are similar to those of butylated hydroxytoluene. (C) 2019 Elsevier B.V. All rights reserved.
Association between homocysteine level and intima-media thickness in patients with first ischemic stroke
(UNIVERSITATSVERLAG ULM GMBH, 2005) Tas, Aysenur; Tas, Fikret; Candan, Ferda; Topaktas, Suat
Objective - Elevated plasma homocysteine may be a causal risk factor for atherosclerosis but this remains controversial. We evaluated the relationship between intima-media thickness of carotid arteries and plasma level of homocysteine in first ischemic stroke patients. Methods and Results - In the patient group, 175 patients with ischemic stroke (89 men and 86 women; mean age 61.2years [SD 6.83]) and in the control group, 110 healthy subjects without ischemic stroke with healthy subjects (58 men and 52 women; mean age 59.8 years [SD 8.15]) were studied. There was not a statistical difference between two groups regarding age, sex, and conventional vascular risk factors between two groups. Logistic regression analysis was carried out by use of a backward selection strategy with continuous variables (age, homocysteine,folate) and categorical variables (hypertension, diabetes mellitus, hypercholesterolemia, history of previous vascular events and smoking) as independent variables and ischemic stroke as the dependent variable. Important independent risk factors for IMT were hypertension (OR 1.08; 95% Cl 1.03 to 1.13, p= 0.001), homocysteine level (OR 12.1; 95% Cl 2.8 to 55, p= 0.002), hypercholesterolemia (OR 2.26; 95% Cl 1.35 to 3.81, p= 0.002), diabetes mellitus (OR 8.01, 95% Cl 2.1 to 28.2, p=0.003), previous vascular events (OR 2.0 1; 95 % Cl 1.22 to 3.31, p=0.005), current smoker (OR 2.11, 95% Cl 1.01 to 3.74, p=0.03), serum folate (OR 7.06; 95%Cl 7.0 to 7.8 1, p=0.002). Conclusions - Finally, increased plasma homocysteine level was an independent risk factor for intima media thickness in first ischemic stroke. So, we think that further comprehensive and long-term studies necessary on this subject.
Biological activities and chemical composition of three honeys of different types from Anatolia
(ELSEVIER SCI LTD, 2007) Kucuk, Murat; Kolayli, Sevgi; Karaoglu, Sengul; Ulusoy, Esra; Baltaci, Cemalettin; Candan, Ferda
In this study, we investigated and compared some chemical properties and in vitro biological activities of three different types of Turkish honey. The first two honey samples were monofloral from chestnut and rhododendron flowers, collected from the east Black Sea region, and the third sample was the heterofloral form of astragalus (Astragalus microcephalus Willd.), thyme (Thymus vulgaris) and other several mountain flowers, collected from Erzincan in Eastern Anatolia. The chemical properties of the honey samples, such as total moisture, ash, total protein, sucrose, invert sugar, diastase activity, hydroxymethylfurfural content and acidity, were determined. Total phenolics, superoxide radical- and peroxynitrite-scavenging activities, and ferric reducing/antioxidant power measurements were used as antioxidant capacity determinants with +/--catechin, butylated hydroxytoluene, ascorbic acid, and trolox (R) used as reference. The antimicrobial activity was studied by the agar diffusion method, using eight bacteria and two yeasts. The mineral contents were also determined by an AAS method. The chestnut flower honey had the highest phenolic content, superoxide radical- scavenging activity and reducing power, while the heterofloral honey sample exhibited the highest peroxynitrite-scavenging activity. The antioxidant activities were also found to be related to the sample concentrations. The mineral content of the chestnut honey was much higher than the others. The samples showed moderate antimicrobial activity against some microorganisms, especially Helicobacter pylori ATCC 49503, Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, Candida tropicalis ATCC 13803 and Candida albicans ATCC 10231. The honey samples studied proved to be a good source of antioxidants and antimicrobial agents that might serve to protect health and fight against several diseases. (c) 2005 Elsevier Ltd. All rights reserved.
Concanavalin a immobilized magnetic poly(glycidyl methacrylate) beads for antibody purification
(WILEY-BLACKWELL, 2012) Akkaya, Birnur; Yavuz, Handan; Candan, Ferda; Denizli, Adil
Concanavalin A (Con A) immobilized magnetic poly(glycidyl methacrylate) (mPGMA) beads in monosize and spherical for (1.62 mu m in diameter) were used for the purification of human immunoglobulin G (IgG) from human plasma. Con A was immobilized by covalent binding onto the mPGMA beads. The maximum IgG adsorption on the mPGMA-Con A beads was observed at pH 6.0. The nonspecific IgG adsorption onto the plain mPGMA beads was very low (0.22 mg/g). Scatchard analysis of the adsorption isotherm for IgG on mPGMA-Con A beads showed an affinity constant (Ka) of 1.39 x 105 M-1 and a theoretical maximum adsorption capacity of 109.1 mg/g. An apparent IgG adsorption capacity of 66.2 mg/g was observed under the experimental conditions. IgG adsorption capacity from human plasma was observed as 48.0 mg/g. The adsorption of human serum albumin from plasma was 2.0 mg/g. The total protein adsorption was determined to be 50.0 mg/g. IgG molecules could be repeatedly adsorbed and eluted with the mPGMA-Con A beads without noticeable loss in the IgG adsorption capacity. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Concanavalin a Immobilized Monosize and Magnetic Poly(glycidyl Methacrylate) Beads for Use in Yeast Invertase Adsorption
(TAYLOR & FRANCIS INC, 2009) Akkaya, Birnur; Uzun, Lokman; Altintas, Evrim Banu; Candan, Ferda; Denizli, Adil
Concanavalin A (Con A) immobilized monosize and magnetic poly(glycidyl methacrylate)[m-poly(GMA)] beads were investigated for specific adsorption of yeast invertase from aqueous solutions. m-Poly(GMA) beads (1.6 m in diameter) were prepared by dispersion polymerization in the presence of Fe3O4 nanopowder. The epoxy groups of m-poly(GMA) beads were opened by base catalyses. Then, Con A was immobilized by covalent binding onto the beads. Con A immobilization amount was 12.5 mg/g. The invertase adsorption capacity of the m-poly(GMA)/Con A beads was 111 mg/g. The maximum invertase adsorption on the m-poly(GMA)/Con A beads was observed at pH 5.5. The optimum activity for both free and adsorbed invertase was observed at 50C. Vmax values were determined as 330 U/mg and 292 U/mg enzyme, for free and adsorbed invertase, respectively. KM values were found to be the same for free and adsorbed invertase (20 mM). Adsorption of invertase via Con A improved the pH stability of invertase. Thermal stability also increased with adsorption. The adsorbed enzyme activity was found to be quite stable in repeated experiments.
Dietilnitrozamin’nin sıçan karaciğer mikrozomal NADH-sitokrom b5 redüktaza invitro etkisi
(Cumhuriyet Üniversitesi, 1995) Candan, Ferda; Atalay, Atilla
11 ÖZET Doktora Tezi DİETİLNİTROZAMİN'İN SIÇAN KARACİ?ER MİKROZOMAL NADH-SİTOKROM b5 REDÜKTAZ A İN VİTRO ETKİSİ FERDA CANDAN Cumhuriyet Üniversitesi Fen Bilimleri Enstitüsü Kimya Anabilim Dalı Danışman: Prof. Dr. Atilla ATALAY Bu çalışmada, kanserojenik ve mutajenik bir bileşik olan Dietilnitrozamin'nin (DENA), saflaştırılan NADH-Sitokrom b$ redüktaz ve onun substratı Si- tokrom b$ üzerine etkisi in vitro olarak incelendi. Enzim ve sitokrom b$ sıçan karaciğer mikrozomlarından Sephadex G- 100 ve DEAE Selüloz kolon kromatografisi ile saflaştırıldı. Enzim aktivitesi, ferrisi- yanit ve sitokrom bs'in indirgenme hızı ile ölçüldü. Saflaştırma sonunda, enzim mikrozomlara oranla ortalama 300 kez saflaştırılıp, % 38 verimle elde edildi. Enzim aktivitesi ferrisiyanit ile ölçüldüğünde, enzimi % 50 inhibe eden DENA derişimi (I50), 6.6x1 0"4 M ; enzimin Km ve Vmax değerleri sırasıyla 0.221 mM ve 899.78 |j.mol dk"1 mg protein "1 bulundu. Enzim aktivitesi sitokrom b$ ile ölçüldüğünde ise I50, Km ve Vmax değerleri sırasıyla 5.7x1 0"4 M, 426 nmol L_1 ve 262.57 nmol dk-1 mg protein "1 şeklinde bulundu. NADH-Sitokrom b5 redüktaz farklı DENA derişimleri ile inkübe edildiğin de Km değerlerinin sabit kaldığı, Vmax değerlerinin değiştiği bulundu. Dolayısı ile inhibisyonun nonkompetitif olduğu saptandı. Enzim substratı olan sitokrom bs, DENA ile inkübe edildiğinde ise DENA'nın indirgenmiş yapıdaki sitokrom bs'i yükseltgediği bulundu. Anahtar Kelimeler: Dietiinitrozamin, NADH-Sitokrom b$ Redüktaz, Sitokrom b$
Iodine deficiency in an eastern region of Turkey
(KARGER, 2006) Ergur, Ayca Torel; Murat, Metin; Candan, Ferda; Tap, Fikret
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Mentha longifolia (L.) Hudson subsp. typhoides (Briq.) Harley var.typhoides’in Hidroksil Radikali ve Hipokloröz Asit Süpürme Aktiviteleri
(2019) Akkoyun, Mahire Bayramoğlu; Candan, Ferda
Çalışmada Mentha longifolia (L.) Hudson subsp. typhoides (Briq.) Harley var. typhoides etanol ekstraktının totalantioksidan kapasitesi ile hidroksil radikali (OH.) ve hipokloröz asit(HOCI) süpürme aktivitesinindeğerlendirilmesi amaçlandı. M. longifolia subsp. typhoides var. typhoides total antioksidan kapasitesi 569±8.57mg AAE/gr olarak belirlendi. Mentha longifolia (L.) Hudson subsp. typhoides (Briq.) Harley var. typhoides etanolekstraktının, hidroksil radikali ve hipokloröz asit süpürücü aktiviteleri incelendiğinde IC50 değerleri ise sırasıyla75.09±2.47 ve 201.43±17.99 µg/mL olarak tesbit edildi. Sonuç olarak M. longifolia subsp. typhoides var. typhoidesetanol ekstraktının total antioksidan kapasitesi ve radikal süpürme aktivitesi değerlendirildiğinde bitkininpotensiyel bir doğal antioksidan kaynağı olabileceği söylenebilir. Ayrıca, oksidatif strese bağlı olarak ortayaçıkabilecek birçok hastalığın önlenmesi veya tedavisinde terapötik ajanlar olarak yüksek etkiye sahip olabileceğidüşünülmektedir.
N-methacryloyl-(L)-histidine methyl ester carrying porous magnetic beads for metal chelate adsorption of cytochrome c
(ELSEVIER SCIENCE BV, 2007) Akkaya, Birnur; Uzun, Lokman; Candan, Ferda; Denizli, Adil
A magnetic metal-chelate adsorbent utilizing N-methacryloyl-(L)-histidine methyl ester (MAH) as a metal-chelating ligand was prepared. MAH was synthesized using methacryloyl chloride and L-histidine methyl ester. Magnetic beads with an average diameter of 50-100 mu m were produced by suspension polymerization of ethylene glycol dimethacrylate (EGDMA) and MAH carried out in a dispersion medium. Specific surface area of the magnetic beads was found to be 80 m(2)/g. Elemental analysis of the magnetic beads for nitrogen was estimated as 70 mu mol MAH/g polymer. Magnetic beads were complexed with the Cu2+ ions directly via MAH for the adsorption of cytochrome c from aqueous solutions. The cytochrome c adsorption on the mag-poly(EGDMA-MAH) beads was 51 mg/g. Cu2+ complexing increased the cytochrome c adsorption significantly. The maximum cytochrome c adsorption capacity of the Cu2+-chelated beads (carrying 68 mu mol Cu2+ per gram of polymer) was found to be 222 mg/g at pH 8.0 in phosphate buffer. Cytochrome c adsorption decreased with increasing temperature. Cytochrome c molecules could be reversibly adsorbed and desorbed ten times with the magnetic adsorbents without noticeable loss in their cytochrome c adsorption capacity. The resulting magnetic chelator beads posses excellent long term storage stability. (c) 2006 Elsevier B.V. All rights reserved.

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