ALFA-GLUKOZİDAZ İNHİBİTÖRLERİ OLARAK KİNOKSALİN TÜREVLERİ: SENTEZ VE BİYOLOJİK DEĞERLENDİRME

Abstract

Amaç: Bu çalışmanın temel amacı, literatürde daha önce tanımlanmış farmakoforik yapılardan faydalanarak, rasyonel tasarım ve sentez stratejileri yoluyla yüksek inhibitör potansiyeline sahip yeni α-glukozidaz inhibitörleri geliştirmektir. Bu araştırma, diabetes mellitus tedavisinde klinik öneme sahip potansiyel ilaç adaylarının keşfine yönelik bilimsel katkı sağlamayı hedeflemektedir. Bu kapsamda, çalışmamızda çeşitli kinoksalin-hidrazon türevleri sentezlenmiş ve bu bileşiklerin α-glukozidaz inhibitör etkinlikleri deneysel olarak incelenmiştir. Ayrıca, enzim inhibisyon mekanizmasının ve ligand-enzim etkileşimlerinin moleküler düzeyde aydınlatılması amacıyla, en yüksek aktiviteye sahip bileşik üzerinde moleküler doking çalışmaları ve enzim inhibisyon kinetik analizleri gerçekleştirilmiştir. Gereç ve Yöntem: Kinoksalin-hidrazon türevleri, üç basamaklı bir sentez protokolü ile elde edilmiştir. Sentezlenen bileşiklerin yapısal karakterizasyonu, FT-IR, ¹H NMR, ¹³C NMR ve HR-MS tekniklerini içeren spektral analiz yöntemleriyle doğrulanmıştır. α-Glukozidaz inhibitör aktivite ve enzim inhibisyon kinetiği çalışmaları, in vitro koşullarda p-nitrofenil-α-D-glukopiranozid (pNPG) substratı kullanılarak standart bir kolorimetrik yöntemle değerlendirilmiştir. Kontrol maddesi olarak akarboz kullanılmıştır. Bileşiklerin inhibitör etkinliklerinin belirlenmesi amacıyla % inhibisyon ve IC₅₀ değerleri hesaplanmıştır. Moleküler doking çalışması, GOLD 5.2 programı kullanılarak gerçekleştirilmiştir. Sonuç ve Tartışma: Biyolojik aktivite değerlendirmeleri, sentezlenen kinoksalin-hidrazon türevlerinin α-glukozidaz enzimine karşı değişen oranlarda inhibitör aktivite sergilediğini göstermiştir. Test edilen bileşikler arasında, N-fenil halkasında para-hidroksi substitüenti taşıyan bileşik 2 en aktif bileşik olup, standart ilaç akarboza (IC50 = 1.211 ± 0.08 mM) kıyasla daha güçlü bir α-glukozidaz inhibitör aktivitesi (IC50 = 0.413 ± 0.048 mM) göstermiştir. Bunun yanı sıra, enzim inhibisyon kinetiği çalışması, en aktif bileşik 2'nin 115.6 µM'lik bir Kᵢ değeri ile α-glukozidaz enzimini kompetitif inhibitör mekanizmasıyla engellediğini ortaya koymuştur. Ayrıca, moleküler doking analizi, bileşik 2 ile enzimin aktif bölgesi arasındaki moleküler etkileşimleri aydınlatmış ve bu etkileşimlerin biyolojik aktivite ile kinetik sonuçlarla tutarlı olduğu gözlemlenmiştir. Bu bulgular, kinoksalin-hidrazon iskeletinin, yeni ve potansiyel antidiyabetik ajanların geliştirilmesinde umut verici bir lider yapı olabileceğini düşündürmektedir.

Keywords

• Diyabet
• hidrazon
• kinoksalin
• sentez
• α-glukozidaz inhibitörleri

QUINOXALINE DERIVATIVES AS α-GLUCOSIDASE INHIBITORS: SYNTHESIS AND BIOLOGICAL EVALUATION

Abstract

Objective: The primary aim of this study is to develop novel α-glucosidase inhibitors with high efficacy through rational design and synthesis strategies utilizing pharmacophoric scaffolds previously defined in the literature. This research aims to contribute to the discovery of clinically relevant potential drug candidates for the treatment of diabetes mellitus. Towards this end, some quinoxaline-hydrazone derivatives were synthetized, and their α-glucosidase inhibition were experimentally investigated. Furthermore, to elucidate the enzyme inhibition mechanism and the ligand-enzyme interactions at the molecular level, molecular docking studies and enzyme inhibition kinetic analyses were conducted on the most active compound. Material and Method: The quinoxaline-hydrazone derivatives were synthesized via a three-step procedure. The structures of the synthesized compounds were confirmed by spectral analysis, including FT-IR, ¹H NMR, ¹³C NMR and HR-MS techniques. The α-glucosidase inhibition and enzyme kinetic study were conducted in vitro with a standard colorimetric assay, using p-nitrophenyl-α-D-glucopyranoside (pNPG) as the substrate. Acarbose was used as a reference standard. Inhibiton % and the IC50 values were calculated to assess the inhibitory potency of the compounds. Molecular docking study was executed by the GOLD 5.2 program. Result and Discussion: The biological activity assessment showed that the synthesized quinoxaline-hydrazone derivatives exhibited inhibitory activity with varying percentages against the α-glucosidase. Among the compounds tested, 2 bearing p-hydroxy subtituent on the N-phenyl ring is the most effective compound and displayed a stronger α-glucosidase inhibitory activity with IC50 value of 0.413 ± 0.048 mM compared to the standard drug acarbose (IC50=1.211 ± 0.08 mM). Furthermore, the kinetic study showed that the most active compound 2 acted as a competitive inhibitor of the α-glucosidase enzyme, with a Ki value of 115.6 µM. Additionally, molecular docking analysis showed that the molecular interactions between compound 2 and the enzyme's active site, and these interactions were observed to be consistent with the biological activity and kinetic results. These findings suggest that the quinoxaline-hydrazone scaffold could serve as a promising lead structure for the development of novel potent antidiabetic agents.

Keywords

• Diabetes
• hyrazone
• quinoxaline
• synthesis
• α-glucosidase inhibitors

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