Süleyman Göksu

Bio: Süleyman Göksu is an academic researcher from Atatürk University. The author has contributed to research in topics: Carbonic anhydrase & Sulfamide. The author has an hindex of 32, co-authored 63 publications receiving 2943 citations.

Synthesis, Antioxidant, and Antiacetylcholinesterase Activities of Sulfonamide Derivatives of Dopamine‐Related Compounds

Abstract: A series of sulfonamides were synthesized from dopamine derivatives. The reactions of amines with methanesulfonyl chloride followed by O-demethylation with BBr3 afforded phenolic sulfonamides. The antioxidant activities of the synthesized phenolic sulfonamides were investigated by thiocyanate method, 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS(center dot+)), 1,1-diphenyl-2-picryl-hydrazyl (DPPH center dot), N,N-dimethyl-p-phenylenediamine (DMPD center dot+), and superoxide anion (O-2(center dot-)) radical scavenging, reducing power, and ferrous ion (Fe2+) chelating assays. Sulfonamides 13-16 showed around 75-85% inhibition on linoleic acid peroxidation. On the other hand, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), -tocopherol, and trolox indicated an inhibition of 90.0%, 85.73%, 73.33%, and 85.73% on peroxidation, respectively, in the same system at the same concentration (10 mu g/mL). Also, the inhibition effects of the synthesized compounds on acetylcholinesterase (AChE) activity were evaluated. AChE was effectively inhibited by sulfanomides 13-16, with K-i values in the range of 33.04 +/- 4.3 to 131.68 +/- 8.8nM.

Antioxidant activity of food constituents: an overview

Abstract: Recently, there has been growing interest in research into the role of plant-derived antioxidants in food and human health. The beneficial influence of many foodstuffs and beverages including fruits, vegetables, tea, coffee, and cacao on human health has been recently recognized to originate from their antioxidant activity. For this purpose, the most commonly methods used in vitro determination of antioxidant capacity of food constituents are reviewed and presented. Also, the general chemistry underlying the assays in the present paper was clarified. Hence, this overview provides a basis and rationale for developing standardized antioxidant capacity methods for the food, nutraceutical, 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 scavenging, superoxide anion radical (O 2 ·− ) scavenging, hydrogen peroxide (H2O2) scavenging, hydroxyl radical (OH·) scavenging, singlet oxygen (1O2) quenching assay and nitric oxide radical (NO·) scavenging 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 detection of antioxidant properties food components. This review consists of two main sections. The first section is devoted to main components in the foodstuffs and beverages. The second general section is some definitions of the main antioxidant methods commonly used for determination of antioxidant activity of components in the foodstuffs and beverages. In addition, there are given some chemical and kinetic basis and technical details of the used methods.

Mitsunobu and Related Reactions: Advances and Applications

Abstract: 10. Patented Literature 2616 10.1. Esterification 2616 10.2. Ether Formation 2619 10.2.1. Etherification without Cyclization 2619 10.2.2. Etherification with Cyclization 2624 10.3. N-Alkylation 2625 10.4. Other Reactions 2627 11. Summary and Outlook 2628 12. Note Added in Proof 2628 13. Abbreviations Used in This Review 2629 14. Acknowledgments 2629 15. Supporting Information Available 2630 16. References 2630

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.