کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10739058 | 1046858 | 2005 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Kinetic study of the quenching reaction of singlet oxygen by tea catechins in ethanol solution
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
1O2DPBFPQH2(–)-epicatechinUbiquinol-10TOCEGCPyrogallolEGCG4-Methylcatechol(+)-catechin - (+) - کاتچینn-Propyl gallate - n-Propyl GallateAntioxidant - آنتی اکسیدانECG - الکتروکاردیوگرام یا نوار قلبSinglet oxygen - اکسیژن مجزاStructure–activity relationship - رابطه ساختار-فعالیتResorcinol - رزورسینولQuenching rate - نرخ خشک کردنoxidation potential - پتانسیل اکسیداسیونplastoquinol - پلاستوکینولCatechol - کاتچولCatechin - کاتچین، کتیچینhigh-performance liquid chromatography - کروماتوگرافی مایعی کاراHPLC - کروماتوگرافی مایعی کارا
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
سالمندی
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
A kinetic study of the quenching reaction of singlet oxygen (1O2) with catechins (catechin (CA), epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), epigallocatechin gallate (EGCG)) and related compounds (5-methoxyresorcinol (MR), 4-methylcatechol (MC), and n-propyl gallate (PG)) was performed in ethanol at 35°C. MR, MC, and PG are considered to be a model of resorcinol (A)-, catechol (B)-, and gallate (G)-rings in catechins, respectively. The overall rate constants, kQ (= kq + kr, physical quenching + chemical reaction), for the reaction of catechins with 1O2 increased in the order of PG < MR < MC < CA < EC < EGC < ECG < EGCG. In a comparison of the rate constants, the relationship between quenching rates and chemical structures is discussed. The catechins which have lower peak oxidation potentials, EP, show higher reactivities. It was observed that the chemical reaction (kr) is almost negligible in the quenching reaction of 1O2 by catechins. The kQ values of EGCG (1.47 Ã 108 Mâ1 sâ1) and ECG (7.81 Ã 107) were found to be larger than those of lipids (1.3 Ã 105-1.9 Ã 105 Mâ1 sâ1), amino acids (<3.7 Ã 107), and DNA (5.1 Ã 105). Further, these values are similar to those (1.15 Ã 108-2.06 Ã 108 Mâ1 sâ1) of α- and γ-tocopherol, ubiquinol-10, and γ-tocopherol hydroquinone (plastoquinol model). The result suggests that catechins may contribute to the protection of oxidative damage in biological systems, by quenching 1O2.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Free Radical Biology and Medicine - Volume 39, Issue 6, 15 September 2005, Pages 752-761
Journal: Free Radical Biology and Medicine - Volume 39, Issue 6, 15 September 2005, Pages 752-761
نویسندگان
Kazuo Mukai, Souichi Nagai, Keishi Ohara,