Özbağcı Duygu İnci
Department of Chemistry, Faculty of Arts and Sciences, Bursa Uludag University, Bursa, 16059, Türkiye.
Arch Biochem Biophys. 2025 Oct;772:110567. doi: 10.1016/j.abb.2025.110567. Epub 2025 Jul 25.
Phenolic acids represent a diverse class of phytochemicals that are abundantly present in fruits, vegetables, and other plant-based sources. The wide-ranging biological properties of these compounds have stimulated considerable interest within the scientific community. Syringic and isovanillic acid, the aromatic natural phytochemicals, are found in fruits and vegetables and exhibit a range of biological activities, including antioxidant and enzyme-modulating effects. In this study, we investigated their binding interactions with biologically significant macromolecules: calf thymus DNA (CT-DNA) and trypsin. The effects of both the phenolic acids on the structure and activity of these macromolecules were analyzed using fluorescence spectroscopy, including quenching type, binding constants, binding sites, thermodynamic parameters, synchronous fluorescence, fluorescence resonance energy transfer (FRET) analysis, two-dimensional (2D), and three-dimensional (3D) fluorescence analysis, effect of metal ions), Fourier transform infrared spectroscopy (FTIR) and molecular docking techniques. The results show that both phenolic acids could bind to CT-DNA via a minor groove mode. The fluorescence experiments indicated that both the phenolic acids bind and cause quenching of trypsin fluorescence. Molecular docking simulations were carried out to examine the interaction profiles of both the phenolic acids with CT-DNA and trypsin. Results revealed that both phenolic acids bind to the DNA minor groove via hydrogen bonding and π-π interactions, with syringic acid showing slightly higher affinity. In the case of trypsin, the isovanillic acid exhibited a stronger binding energy and formed a more compact interaction pattern within the enzyme's active site. These findings support the potential of both the phenolic acids to form stable, non-covalent complexes with biologically relevant macromolecules and contribute to their observed antioxidant and enzymatic effects. The radical scavenging activity of both phenolic acids was measured via the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) method and reported in terms of their IC value. Based on the results, it can be inferred that the radical scavenging potential of both phenolic acids is significantly affected by the number and position of their substituents.
酚酸是一类多样的植物化学物质，大量存在于水果、蔬菜和其他植物性来源中。这些化合物广泛的生物学特性引起了科学界的极大兴趣。丁香酸和异香草酸这两种芳香天然植物化学物质存在于水果和蔬菜中，并表现出一系列生物活性，包括抗氧化和酶调节作用。在本研究中，我们研究了它们与具有生物学意义的大分子：小牛胸腺DNA（CT-DNA）和胰蛋白酶的结合相互作用。使用荧光光谱分析了这两种酚酸对这些大分子的结构和活性的影响，包括猝灭类型、结合常数、结合位点、热力学参数、同步荧光、荧光共振能量转移（FRET）分析、二维（2D）和三维（3D）荧光分析、金属离子的影响）、傅里叶变换红外光谱（FTIR）和分子对接技术。结果表明这两种酚酸都可以通过小沟模式与CT-DNA结合。荧光实验表明这两种酚酸都能结合并导致胰蛋白酶荧光猝灭。进行分子对接模拟以检查这两种酚酸与CT-DNA和胰蛋白酶的相互作用情况。结果显示这两种酚酸都通过氢键和π-π相互作用与DNA小沟结合，丁香酸的亲和力略高。在胰蛋白酶的情况下，异香草酸表现出更强的结合能，并在酶的活性位点内形成更紧密的相互作用模式。这些发现支持了这两种酚酸与生物学相关大分子形成稳定非共价复合物的潜力，并有助于它们观察到的抗氧化和酶促作用。通过2,2-二苯基-1-苦基肼（DPPH）法测量了这两种酚酸的自由基清除活性，并以它们的IC值报告。根据结果可以推断，这两种酚酸的自由基清除潜力受到其取代基数量和位置的显著影响。
