Dilek Bilgiç Alkaya

Marmara University · Department of Analytical Chemistry

In the last decade, the processes involved in biomineralization has greatly developed, leading to the production of a new generation of biomaterials. Calcium phosphate ceramic materials attract special interest due to their bioactive and biocompatible properties in biomaterials. Most of marine structures contains calcium carbonate (calcite or arago...

L-alanine and β-alanine are important biological molecules and have zwitterion structure. In this study, L- alanine and β-alanine’s microscopic protonation constants and thermodynamic parameters (enthalpy, entropy, and free energy changes) for the proton–ligand systems of L-alanine methyl ester, β-alanine and β-alanine methyl ester have been determ...

Bu çalışma, Tüberküloz hastalarında antitüberküloz ilaçların etkili kombine formulasyonlarının üretilmesindeki zorluklar nedeniyle yeni kombinasyon formulasyonlarının değerlendirilmesi amacıyla tasarlanmıştır. Bunun için tedavide etkin antitüberkülostatikler olan pirazinamid, izoniazid, rifampisin ve etambutol biyolojik olarak parçalanabilen polika...

The main aim of this study is to formulate the combination of the bioactive composite containing chitosan/β -tricalcium phosphate (CH/β-TCP) as potential drug delivery platforms for the sustained release of antibiotics. Herein the mode of amoxicillin (AMX) maintained in the β-TCP/chitosan composite was characterized using XRD, FT-IR to confirm the...

The marine species are specially used for the fabrication of bioceramic nano-powders with natural methods for their use in controlled drug delivery. However, there are only very limited studies regarding the production and synthesis of hydroxyapatite (HA)–based drug delivery systems from marine structures. In this study, poly (vinyl alcohol) (PVA)...

Bone tissue engineering has begun to draw attention in recent years. The interactive combination of biomaterials and cells is part of bone tissue engineering. Sodium alginate (SA) is a biologically compatible, degradable, non-toxic natural polymer accepted by the human body and is widely used in the field of tissue engineering. Polylactic acid (PLA...

Rheum species are important medicinal herbs, often used in pharmacological research, due to the presence of anthracene derivatives in the subterranean parts of the plant. In this study, we intended to assess its antioxidant capacity, in correlation with the method of extraction. For this purpose, Rheum ribes extraction was realized with four solven...

Benzoic acid (C 6 H 5 COOH) is widely used in the food industry as a preservative in acid foods, under code number E210, owing to its antimicrobial activity against various bacteria, yeasts and fungi involved in food poisoning and food spoilage. It is a safe preservative used to protect taste, odor, appearance, structure of food during storage, pre...

An ion chromatographic (IC) method with suppressed conductivity detection (CD) was developed and validated for the quantitative determination of fluoride, chloride, nitrite, nitrate, sulphite, sulphate, phosphate ions in 18 wine samples (W: white wine samples; R: red wine samples). A mixed solution of sodium carbonate and sodium hydroxide was used...

Ellagic acid (EA) is a polyphenol, which exists in fruits and nuts in free form or derivatives, like hydrolyzable ellagitannins (ETs). EA has a chemoprotective effect in cellular models by reducing oxidative stress, and also antiproliferative and antioxidant properties in many in vitro and animal models. EA was identified and quantified by the curr...

The aim of this study was to examine for the first time antioxidant properties from ethanol extracts of Achillea grandifolia flowers, leaves and stems using various antioxidant capacity methods. Subsequently, phenolic compounds in the extracts were identified for the first time by ESI-Q-TOF LC/MS and HPLC-DAD methods. The phenolic compounds in A. g...

The aim of this study was to analysis of natural dyestuffs from Achillea grandifolia Friv. leaves, flowers and stems in wool dyeing. The optimum dye extraction temperature and time were determined by spectrophotometrically. Natural dyeing was carried out with the optimized dye extract on unmordanted wool fabrics. The dyestuffs were analysed using e...

In this paper high performance liquid chromatography method was developed for the determination of natamycin in dairy product in Turkish market. Chromatographic separation was achieved on a C8 column (150 mm x 4.6 mm x 5 μm 100 mm) with a mobile phase of methanol: water : acetic acid (12:8:1 v/v/v), at 1ml/min flow rate with DAD detection at 303 nm...

This study was aimed at developing RP-HPLC method for determination of natamycin in Turkish yoghurt. Chromatographic separation was achieved on a C8 column (150 mm × 4.6 mm × 5 µ m) with a mobile phase of methanol : water : acetic acid (12 : 8 : 1 v/v/v), at 1 mL/min flow rate with a detection of 303 nm. Natamycin was spiked into handmade yoghurt...

Bitki caylari Turkiye’de oldukca fazla miktarda tuketilmektedir. Caylar pek cok faydalarinin yanisira yapilarinda agir metalleri de barindirirlar ve cevre kirliligi arttikca caylardaki agir metal kirliligi de artmaktadir.Arastirmada adacayi, biberiye, sari kantaron, ihlamur, nane, kekik, papatya, rezene, yesilcay, yaban mersini kullanilmis ve kursu...

GİRİŞ Bitkisel çaylar bitkilerin köklerinin, kök gövdelerinin, dal sürgünlerinin, yapraklarının, çiçeklerinin, kabuklarının, meyvelerinin veya tohumlarının aromatik kısımlarının kurutularak, kaynar suda içime uygun hale getirilerek hazırlanmasına dayanan karışımlardır. Bunun için kullanılacak drog çiçek ise tamamen açtıktan sonra, yaprak ise tek te...

In this study, a potentiometric titration technique has been used to determine stability constants for the various complexes of Zn(II), Co(II), Cd(II) and Mn(II) with creatinine and two amino acids. Stability constants of ternary systems have been evaluated by the method suggested by Irving-Rossotti at 25°C and 0.11M ionic strength (kept constant w...

Bioceramic nanopowders, currently one of the most demanding challenges for producing new biomaterials, have been tackled only when starting from chemical reagents. There are few studies aiming at producing hydroxyapatite nanopowders from naturally derived raw materials, such as nacre shells. Natural species of sea origin, such as corals and nacres,...

There are thousands of land snail species, ranging in size from 1 mm to the Giant African Snail growing up to a foot long. Two species, known as escargot, helix aspersa and helix pomatia , are commercially important. Helix pomatia is abundant in Turkey. Those snails are exported usually without shells. Shells are damped to trash sites or used as su...

Atrial fibrillation (AF) is a common complication of cardiovascular surgery and its mechanisms are not well understood. The aim of our study was a prospective investigation of the relationship between AF development and tissue or blood magnesium levels. This prospective observational study evaluated 20 patients undergoing elective initial coronary...

Objective: Atrial fibrillation (AF) is a common complication of cardiovascular surgery and its mechanisms are not well understood. The aim of our study was a prospective investigation of the relationship between AF development and tissue or blood magnesium levels. Methods: This prospective observational study evaluated 20 patients undergoing electi...

Alizarin, which consists of 1,2 dihydroxyanthraquinone, is the common madder of anthraquinoid pigment group. It has been used for textiles, food and medicine. The colour of alizarin is light brown and dissociates low in water. It is in the root of Rubia tinctorum plant. The plant is 50-80 cm high and its trunk is cornered, hard and thorny. In the p...

Titration potentiometry and spectrophotometry have both been used to determine stability constants for mixed complexes of Cu(II) with creatinine and EDTA. Stability constants of the ternary system were evaluated by a method suggested by the Irving-Rossotti procedure. Conditional constants were established as a function of pH; the maximum values of...

Alizarin, which consists of 1,2 dihydroxyanthraquinone, is the common madder of the anthraquinoid pigment group. It has been used for textiles, food and medicine. The colour of alizarin is light brown and dissociates low in water. It is in the root of Rubia tinctorum plant. The plant is 50-80 cm high and its trunk is cornered, hard and thorny. In t...

Creatinine, an important bioligand, and its main lautometric forms include donor groups with strong coordination capacity In this study, the stability constants of binary and mixed ligand complexes formed by creatinine and L-glutamic acid -with Co(II), Cu(II), Mn(II) were determined by the Calvin-Bjerrum and Irving-Rossotti methods.

Creatinine is a physiological component of blood, brain and muscles and an important bioligand, which is the last product of the nitrogen metabolism in the vertebrates. In this study, the stability constants of binary complexes formed by creatinine with Zn(II) and Cd(II), and of the mixed-ligand complexes Zn(II)-creatinine-1-asparagine and Zn(II) c...

Creatinine is a physiological component of blood, brain and muscles and an important bioligand, which is the last product of the nitrogen metabolism in the vertebrates. In this study, the stability constants of binary complexes formed by creatinine with Cu(II), Co(II), Mn(II), Cr(III), and of the mixed-ligand complex Cu(II)-creatinine-l-asparagine...

In the present study, the stability constants of the complexes which were formed from N-benzylideneaniline (BDA), N-benzylidene-4-chloroaniline (BDCA), N-(4-chlorobenzylidene)aniline (CBDA), N-benzylidene-4-nitroaniline (BDNA) and N-benzylidene-4-hydroxyaniline (BDHA) with chromium (III), manganese (II), cobalt (II), nickel (II), copper (II), zinc...

The stability constants of the complexes which were formed from N-salicylidene-aniline (HBDA), N-salicylidene-4-bromoaniline (HBDBrA), N-salicylidene-4-chloroaniline (HBDCA) with chromium(III), manganese(II), cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) were determined potentiometrically by using Calvin-Bjerrum and Irwing-Rossotti m...