Aydın Aktaş

Bio: Aydın Aktaş is an academic researcher from İnönü University. The author has contributed to research in topics: Carbene & PEPPSI. The author has an hindex of 11, co-authored 49 publications receiving 475 citations. Previous affiliations of Aydın Aktaş include Karadeniz Technical University.

meta‐Cyanobenzyl substituted benzimidazolium salts: Synthesis, characterization, crystal structure and carbonic anhydrase, α‐glycosidase, butyrylcholinesterase, and acetylcholinesterase inhibitory properties

Abstract: meta-Cyanobenzyl-substituted N-heterocyclic carbene (NHC) precursors were synthesized by the reaction of a series of N-(alkyl)benzimidazolium with 3-bromomethyl-benzonitrile. These benzimidazolium salts were characterized by using 1 H NMR, 13 C NMR, FTIR spectroscopy, and elemental analysis techniques. The molecular and crystal structures of 2f and 2g complexes were obtained by using the single-crystal X-ray diffraction method. The derivatives of these novel NHC precursors were effective inhibitors of α-glycosidase (AG), the cytosolic carbonic anhydrase I and II isoforms (hCA I and II), butyrylcholinesterase (BChE), and acetylcholinesterase (AChE) with Ki values in the range of 1.01-2.12 nM for AG, 189.56-402.44 nM for hCA I, 112.50-277.37 nM for hCA II, 95.45-352.58 nM for AChE, and 132.91-571.18 nM for BChE. In the last years, inhibition of the CA enzyme has been considered as a promising factor for pharmacologic intervention in a diversity of disturbances such as obesity, glaucoma, cancer, and epilepsy.

Novel N-propylphthalimide- and 4-vinylbenzyl-substituted benzimidazole salts: Synthesis, characterization, and determination of their metal chelating effects and inhibition profiles against acetylcholinesterase and carbonic anhydrase enzymes

Abstract: The novel N-propylphthalimide-substituted and 4-vinylbenzyl-substituted N-heterocyclic carbene (NHC) precursors were synthesized by N-substituted benzimidazolium with aryl halides. The novel N-propylphthalimide-substituted and 4-vinylbenzyl-substituted NHC precursors have been characterized by using 1 H NMR, 13 C NMR, FTIR spectroscopy, and elemental analysis techniques. They were tested for the inhibition of AChE and hCA enzymes and demonstrated efficient inhibition profiles with Ki values in the range of 351.0-1269.9 nM against hCA I, 346.6-1193.1 nM against hCA II, and 19.0-76.3 nM against AChE. On the other hand, acetazolamide, a clinically used molecule, utilized as CA inhibitor, obtained a Ki value of 1246.7 nM against hCA I and 1407.6 nM against hCA II. Additionally, tacrine inhibited AChE and obtained a Ki value of 174.6 nM.

Antioxidants and antioxidant methods: an updated overview

Abstract: Antioxidants had a growing interest owing to their protective roles in food and pharmaceutical products against oxidative deterioration and in the body and against oxidative stress-mediated pathological processes. Screening of antioxidant properties of plants and plant-derived compounds requires appropriate methods, which address the mechanism of antioxidant activity and focus on the kinetics of the reactions including the antioxidants. Many studies evaluating the antioxidant activity of various samples of research interest using different methods in food and human health have been conducted. These methods are classified, described, and discussed in this review. Methods based on inhibited autoxidation are the most suited for termination-enhancing antioxidants and for chain-breaking antioxidants, while different specific studies are needed for preventive antioxidants. For this purpose, the most common methods used in vitro determination of antioxidant capacity of food constituents were examined. Also, a selection of chemical testing methods was critically reviewed and highlighted. In addition, their advantages, disadvantages, limitations and usefulness were discussed and investigated for pure molecules and raw extracts. The effect and influence of the reaction medium on the performance of antioxidants are also addressed. Hence, this overview provides a basis and rationale for developing standardized antioxidant methods for the food, nutraceuticals, and dietary supplement industries. In addition, the most important advantages and shortcomings of each method were detected and highlighted. The chemical principles of these methods are outlined and critically discussed. The chemical principles of methods of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS·+) scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH·) radical scavenging, Fe3+-Fe2+ transformation assay, ferric reducing antioxidant power (FRAP) assay, cupric ions (Cu2+) reducing power assay (Cuprac), Folin-Ciocalteu reducing capacity (FCR assay), peroxyl radical (ROO·), superoxide radical anion (O2·-), hydrogen peroxide (H2O2) scavenging assay, hydroxyl radical (OH·) scavenging assay, singlet oxygen (1O2) quenching assay, nitric oxide radical (NO·) scavenging assay and chemiluminescence assay are outlined and critically discussed. Also, the general antioxidant aspects of main food components were discussed by a number of methods, which are currently used for the detection of antioxidant properties of food components. This review consists of two main sections. The first section is devoted to the main components in the food and pharmaceutical applications. The second general section comprises some definitions of the main antioxidant methods commonly used for the determination of the antioxidant activity of components. In addition, some chemical, mechanistic and kinetic basis, and technical details of the used methods are given.

Trocar site hernia after laparoscopic surgery: a qualitative systematic review

Abstract: There is a risk of developing a trocar site hernia (TSH) after laparoscopic surgery, but data is sparse and based mostly on retrospective studies with a short and poorly defined follow-up period. Surgical approaches and patient-related co-morbidity have also been suggested as risk factors for development of TSH. The aim of the present review was to perform a qualitative systematic analysis to estimate the incidence of TSH and to discuss the surgical and patient-related risk factors for development of TSH. The literature search was until 19 May 2010. Studies with TSH, defined as either operation for TSH or a hernia found during clinical follow-up, were included. We included randomised controlled trials, prospective non-controlled studies including >200 patients, and retrospective studies including >200 patients. The review was completed according to the PRISMA guidelines. We included 19 studies in adults and 3 studies in paediatric patients (<18 years), and a total of 30,568 adults and 1,098 children were analysed. The overall incidence of TSH was 0–5.2%. TSH occurred most often (96%) in trocar sites of a minimum of 10 mm, located mostly in the umbilicus region (82%). Data supported a higher incidence of TSH when the trocar site fascia was not sutured, and in pre-school children undergoing a laparoscopic procedure. Current data suggests a relatively low incidence of TSH but that all trocar incisions of a minimum of 10 mm should be closed. In pre-school children undergoing laparoscopic surgery, all port sites should be closed.