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Flavonoids in Microheterogeneous Media, Relationship between Their Relative Location and Their Reactivity towards Singlet Oxygen.

Günther G, Berríos E, Pizarro N, Valdés K, Montero G, Arriagada F, Morales J - PLoS ONE (2015)

Bottom Line: In addition, these compounds do not produce changes in fluorescence anisotropy of DPH, discarding their location in deeper regions of the lipid bilayer.The determined chemical reactivity sequence is similar in all the studied media (kaempferol < quercetin < morin).Morin is approximately 10 times more reactive than quercetin and 20 to 30 times greater than kaempferol, depending on the medium.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Química Orgánica y Fisicoquímica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile.

ABSTRACT
In this work, the relationship between the molecular structure of three flavonoids (kaempferol, quercetin and morin), their relative location in microheterogeneous media (liposomes and erythrocyte membranes) and their reactivity against singlet oxygen was studied. The changes observed in membrane fluidity induced by the presence of these flavonoids and the influence of their lipophilicity/hydrophilicity on the antioxidant activity in lipid membranes were evaluated by means of fluorescent probes such as Laurdan and diphenylhexatriene (DPH). The small differences observed for the value of generalized polarization of Laurdan (GP) curves in function of the concentration of flavonoids, indicate that these three compounds promote similar alterations in liposomes and erythrocyte membranes. In addition, these compounds do not produce changes in fluorescence anisotropy of DPH, discarding their location in deeper regions of the lipid bilayer. The determined chemical reactivity sequence is similar in all the studied media (kaempferol < quercetin < morin). Morin is approximately 10 times more reactive than quercetin and 20 to 30 times greater than kaempferol, depending on the medium.

No MeSH data available.


Stern—Volmer type plot for singlet oxygen deactivation by kaempferol in erythrocyte membranes at 25°C.
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pone.0129749.g007: Stern—Volmer type plot for singlet oxygen deactivation by kaempferol in erythrocyte membranes at 25°C.

Mentions: In this work, the total rate constants (kT) for the reaction of singlet oxygen with flavonoids in erythrocyte membranes dispersed in D2O (pD 7.4) were obtained by measuring the first-order rate decay (Eq 7) of luminescence in the presence and absence of each flavonoid.τ−1=τ0−1+kT[FLAV](7)where τ-1 is singlet oxygen lifetime in presence of flavonoid and τ0−1 is singlet oxygen lifetime in the absence of FLAV (τ0−1 = 1/kd). Values of kT were calculated from slopes of τ−1 vs. [FLAV] plots. Fig 7 shows Stern-Volmer plot for singlet oxygen deactivation by kaempferol in erythrocyte ghost membranes.


Flavonoids in Microheterogeneous Media, Relationship between Their Relative Location and Their Reactivity towards Singlet Oxygen.

Günther G, Berríos E, Pizarro N, Valdés K, Montero G, Arriagada F, Morales J - PLoS ONE (2015)

Stern—Volmer type plot for singlet oxygen deactivation by kaempferol in erythrocyte membranes at 25°C.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4476713&req=5

pone.0129749.g007: Stern—Volmer type plot for singlet oxygen deactivation by kaempferol in erythrocyte membranes at 25°C.
Mentions: In this work, the total rate constants (kT) for the reaction of singlet oxygen with flavonoids in erythrocyte membranes dispersed in D2O (pD 7.4) were obtained by measuring the first-order rate decay (Eq 7) of luminescence in the presence and absence of each flavonoid.τ−1=τ0−1+kT[FLAV](7)where τ-1 is singlet oxygen lifetime in presence of flavonoid and τ0−1 is singlet oxygen lifetime in the absence of FLAV (τ0−1 = 1/kd). Values of kT were calculated from slopes of τ−1 vs. [FLAV] plots. Fig 7 shows Stern-Volmer plot for singlet oxygen deactivation by kaempferol in erythrocyte ghost membranes.

Bottom Line: In addition, these compounds do not produce changes in fluorescence anisotropy of DPH, discarding their location in deeper regions of the lipid bilayer.The determined chemical reactivity sequence is similar in all the studied media (kaempferol < quercetin < morin).Morin is approximately 10 times more reactive than quercetin and 20 to 30 times greater than kaempferol, depending on the medium.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Química Orgánica y Fisicoquímica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile.

ABSTRACT
In this work, the relationship between the molecular structure of three flavonoids (kaempferol, quercetin and morin), their relative location in microheterogeneous media (liposomes and erythrocyte membranes) and their reactivity against singlet oxygen was studied. The changes observed in membrane fluidity induced by the presence of these flavonoids and the influence of their lipophilicity/hydrophilicity on the antioxidant activity in lipid membranes were evaluated by means of fluorescent probes such as Laurdan and diphenylhexatriene (DPH). The small differences observed for the value of generalized polarization of Laurdan (GP) curves in function of the concentration of flavonoids, indicate that these three compounds promote similar alterations in liposomes and erythrocyte membranes. In addition, these compounds do not produce changes in fluorescence anisotropy of DPH, discarding their location in deeper regions of the lipid bilayer. The determined chemical reactivity sequence is similar in all the studied media (kaempferol < quercetin < morin). Morin is approximately 10 times more reactive than quercetin and 20 to 30 times greater than kaempferol, depending on the medium.

No MeSH data available.