fa مقایسه‌ی خواص چلاتینگ یون آهن، رادیکال‌زدایی و ضد تیروسینازی اسانس آویشن دنایی با آویشن تجاری و تیمول مقاله پژوهشی Original Research Article <p style="text-align: justify;"><strong><em>Background and Objective:</em></strong> Utilization of plants as antioxidants in food processing has a potential for substitution of synthetic antioxidants. In the present work, some unexplored biological activities of <em>Thymus daenensis</em>, commercial <em>thyme</em> essential oils and thymol were comparatively studied.<br> <strong><em>Materials and Methods:</em></strong> Ferrous ion chelating was assessed by spectrophotometry by mixing the essential oils with diluted FeSO₄ followed by addition of ferrozine. Antioxidative properties were assessed by beta carotene bleaching and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging tests. Gallic acid equivalent of ferric reduction was carried out using FeCl₃. Super oxide anion radical scavenging was determined using xanthine oxidase and anti tyrosinase inhibitory activity was determined by a spectrophotometry method using a modified dopachrome method with L-DOPA as the substrate.<br> <strong><em>Results: </em></strong>Chelating reaction of <em>T. daenensis</em> oil was dose dependent, and its super oxide anion radical scavenging property was higher than the commercial oil. Lipid peroxidation inhibition by <em>T. daenensis</em> oil was stronger and those of the commercial oil and thymol were approximately equal. DPPH free radical scavenging property of<br> <em>T. daenensis</em> oil was higher than trolox, butylated hydroxytoluene and anisol (BHT and BHA). Ferric-reducing antioxidant power (FRAP) of <em>T. daenensis</em> oil was greater. The total phenolics anti tyrosinase IC₅₀ were also determined.<br> <strong><em>Conclusion:</em></strong> The results point to the nutritional value of these plants in preventing formation of toxic reactive oxygen species, and show that Thymus daenensis, as a good antioxidant, can directly scavenge free radicals. The results from biological properties of Thymus daenensis are indicative of its potentials for use in food and drug industries.</p> Chelating, Antioxidant, Super oxide anion radical scavenging, Antityrosinase, Essential oils, Thymus 41 52 http://journal.zums.ac.ir/browse.php?a_code=A-10-4-604&slc_lang=fa&sid=1 Mahdi Dadashpour مهدی داداش پور 5200319475328460060052 5200319475328460060052 No College of Basic Sciences, Shahed University, Tehran, Iran Iraj Rasooli ایرج رسولی rasooli@shahed.ac.ir 5200319475328460060053 5200319475328460060053 Yes Dept. of Biology, College of Basic Sciences, Shahed University, Tehran, Iran Fatemeh Sefidkon فاطمه سفیدکن 5200319475328460060054 5200319475328460060054 No Research Institute of Forests and Rangelands, Tehran, Iran Masoud Taghizadeh مسعود تقی‌زاده 5200319475328460060055 5200319475328460060055 No Dept. of Chemistry, College of Basic Sciences, Shahed University, Tehran, Iran Shaliba Darvish Alipour Astaneh شکیبا درویش علیپور آستانه 5200319475328460060056 5200319475328460060056 No College of Basic Sciences, Shahed University, Tehran, Iran