Furthermore, the ratio kr/kT for the complex equal to 0.022 indicates that the physical quenching of 1O2 predominates largely over the chemical reaction, then, the quenching effect of Rutin - Ca+2 complex take place practically without antioxidant loss, a very wanted characteristic of molecules with capabilities to protect biological systems under oxidative stress conditions. The first half-reaction is the reduction of the flavin via hydride transfer from the alcohol (the reductive half-reaction), and the second half-reaction is the oxidation of the reduced flavin by molecular oxygen, the final acceptor (oxidative half-reaction) ( 4 ).
#Oxygen reactivity free
Although the energy of :O2 is only 92 kJ/mol higher than that of ground state oxygen, its chemical reactivity is completely different because it is now spin matched with ground state molecules susceptible to oxidation. Oxygen-derived free radicals and related oxidants are ubiquitous and short-lived intermediates formed in aerobic organisms throughout life. Reactive Oxygen Species (ROS) are radical or molecular species whose physical-chemical properties are well-known both on thermodynamic and kinetic points of view. The high value of the physical quenching rate constant in water, suggest that the association complex Rutin – Ca+2 could be a more efficient antioxidant in biological media than the glycoside. Singlet oxygen might diffuse about 0.01 to 0.02 mm in a cellular environment (Moan et al., 1979). The complex reacts with moderate to high rates with singlet oxygen with total rate constants (kT = kr + kq) of (5.82 ± 0.47) x 105 M-1 s-1 and (509.7 ± 40.8) x 105 M-1s-1 and chemical reaction constants of (1.10 ± 0.08) x 105 M-1 s-1 and (8.99 ± 0.91) x 105 M-1 s-1 in methanol and water, respectively.
The results obtained, indicates that the glycoside Rutin forms a stable association complex with Ca+2 ions in both, MeOH and water as solvents with stability constants equal to 5.5 M-1 and 10.3 M-1. In this work we report the results of singlet oxygen quenching by the complex form edfrom the interaction between the glycoside rutin and Ca+2, the most abundant macroelement in the humanbody. Furthermore, in the presence of metal ions, the flavonoid reactivity towards singlet oxygen is enhanced. Elemental oxygen, O 2, makes up about 20 of the earths atmosphere by weight. The reactivity of metals can differ a lot: Sodium reacts very fast with oxygen. Some metals can also burn, or they can form oxides just by being exposed to air at room temperature. The speed of the reaction depends on the reactivity of the metal. Non-metals and non-metal compounds usually form oxides by burning. Reactions of metals with oxygen When metals react with oxygen, metal oxides are formed. However, the OER is kinetically sluggish and requires a catalyst presence ( 4 6 ). Almost all elements, and many compounds, react with it, to form oxides. Flavonoids deactivate efficiently singlet oxygen and could be valuable antioxidants in systems under oxidative stress, in particular if a flavonoid rich diet was previously consumed. The oxygen evolution reaction (OER) is a key half-reaction in hydrogen-oxygen electrolyzers, rechargeable metal-air batteries, and regenerative fuel cells.
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