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Prooxidative Potential of Photo-Irradiated Aqueous Extracts of Grape Pomace, a Recyclable Resource from Winemaking Process.

Tsukada M, Nakashima T, Kamachi T, Niwano Y - PLoS ONE (2016)

Bottom Line: That is, reduction of dissolved oxygen by proton-coupled electron transferred from the photo-oxidized phenolic hydroxyl group would form H2O2.The resultant H2O2 was then photolyzed to generate hydroxyl radical (•OH).The prooxidant activity of the photo-irradiated extract indicated by •OH yield was more potent than that of the photo-irradiated GSE and (+)-catechin, and this was well reflected in their bactericidal activity in which the photo-irradiated extract could kill the bacteria more efficiently than did the photo-irradiated GSE and (+)-catechin.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 2-12-1-M6-7 Ookayama, Meguro-ku, Tokyo, 152-8250, Japan.

ABSTRACT
Our previous study revealed that aqueous extract of grape pomace obtained from a winemaking process could exert bactericidal action upon photo-irradiation via reactive oxygen species (ROS) formation. In the present study, we focused on chemical composition and prooxidative profile of the extract. Liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) analysis showed that polyphenolic compounds including catechin monomers, dimers, trimers, and polyphenolic glucosides were contained. The polyphenol rich fraction used for the LC-ESI-MS analysis generated hydrogen peroxide (H2O2) upon photo-irradiation possibly initiated by photo-oxidation of phenolic hydroxyl group. That is, reduction of dissolved oxygen by proton-coupled electron transferred from the photo-oxidized phenolic hydroxyl group would form H2O2. The resultant H2O2 was then photolyzed to generate hydroxyl radical (•OH). The prooxidative profile of the extract in terms of •OH generation pattern upon photo-irradiation was similar to that of grape seed extract (GSE) as an authentic polyphenol product and (+)-catechin as a pure polyphenolic compound, and in all the three samples •OH generation could be retained during photo-irradiation for at least a couple of hours. The prooxidant activity of the photo-irradiated extract indicated by •OH yield was more potent than that of the photo-irradiated GSE and (+)-catechin, and this was well reflected in their bactericidal activity in which the photo-irradiated extract could kill the bacteria more efficiently than did the photo-irradiated GSE and (+)-catechin.

No MeSH data available.


Related in: MedlinePlus

Effect of different treatment conditions on DMPO-OH yields.Each value represents the mean with standard deviation (n = 3). [D(+)L(+)][D(+)L(-)]: sample with DMPO was photo-irradiated for 1 min, and kept under a light shielding condition for 1 min, [D(+)L(+)][D(+)L(+)]: sample with DMPO was photo-irradiated for 2 min, and [D(-)L(+)][D(+)L(+)]: sample without DMPO was photo-irradiated for 1 min, and further irradiated with DMPO for 1 min.
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pone.0158197.g010: Effect of different treatment conditions on DMPO-OH yields.Each value represents the mean with standard deviation (n = 3). [D(+)L(+)][D(+)L(-)]: sample with DMPO was photo-irradiated for 1 min, and kept under a light shielding condition for 1 min, [D(+)L(+)][D(+)L(+)]: sample with DMPO was photo-irradiated for 2 min, and [D(-)L(+)][D(+)L(+)]: sample without DMPO was photo-irradiated for 1 min, and further irradiated with DMPO for 1 min.

Mentions: Fig 10 shows DMPO-OH generation under following there conditions: 1) each sample with 300 mM DMPO was irradiated with LED light for 1 min, and kept under a light shielding condition for 1 min, expressed as [D(+)L(+)][D(+)L(-)], 2) each sample with 300 mM DMPO was irradiated with LED light for 2 min, expressed as [D(+)L(+)][D(+)L(+)], and 3) each sample without DMPO was irradiated with LED light for 1 min, and further irradiated in the presence of 300 mM DMPO for 1 min, expressed as [D(-)L(+)][D(+)L(+)], where D and L indicate DMPO and LED light, respectively. DMPO-OH levels in each sample were almost the same regardless of the L and D treatment conditions.


Prooxidative Potential of Photo-Irradiated Aqueous Extracts of Grape Pomace, a Recyclable Resource from Winemaking Process.

Tsukada M, Nakashima T, Kamachi T, Niwano Y - PLoS ONE (2016)

Effect of different treatment conditions on DMPO-OH yields.Each value represents the mean with standard deviation (n = 3). [D(+)L(+)][D(+)L(-)]: sample with DMPO was photo-irradiated for 1 min, and kept under a light shielding condition for 1 min, [D(+)L(+)][D(+)L(+)]: sample with DMPO was photo-irradiated for 2 min, and [D(-)L(+)][D(+)L(+)]: sample without DMPO was photo-irradiated for 1 min, and further irradiated with DMPO for 1 min.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4920348&req=5

pone.0158197.g010: Effect of different treatment conditions on DMPO-OH yields.Each value represents the mean with standard deviation (n = 3). [D(+)L(+)][D(+)L(-)]: sample with DMPO was photo-irradiated for 1 min, and kept under a light shielding condition for 1 min, [D(+)L(+)][D(+)L(+)]: sample with DMPO was photo-irradiated for 2 min, and [D(-)L(+)][D(+)L(+)]: sample without DMPO was photo-irradiated for 1 min, and further irradiated with DMPO for 1 min.
Mentions: Fig 10 shows DMPO-OH generation under following there conditions: 1) each sample with 300 mM DMPO was irradiated with LED light for 1 min, and kept under a light shielding condition for 1 min, expressed as [D(+)L(+)][D(+)L(-)], 2) each sample with 300 mM DMPO was irradiated with LED light for 2 min, expressed as [D(+)L(+)][D(+)L(+)], and 3) each sample without DMPO was irradiated with LED light for 1 min, and further irradiated in the presence of 300 mM DMPO for 1 min, expressed as [D(-)L(+)][D(+)L(+)], where D and L indicate DMPO and LED light, respectively. DMPO-OH levels in each sample were almost the same regardless of the L and D treatment conditions.

Bottom Line: That is, reduction of dissolved oxygen by proton-coupled electron transferred from the photo-oxidized phenolic hydroxyl group would form H2O2.The resultant H2O2 was then photolyzed to generate hydroxyl radical (•OH).The prooxidant activity of the photo-irradiated extract indicated by •OH yield was more potent than that of the photo-irradiated GSE and (+)-catechin, and this was well reflected in their bactericidal activity in which the photo-irradiated extract could kill the bacteria more efficiently than did the photo-irradiated GSE and (+)-catechin.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 2-12-1-M6-7 Ookayama, Meguro-ku, Tokyo, 152-8250, Japan.

ABSTRACT
Our previous study revealed that aqueous extract of grape pomace obtained from a winemaking process could exert bactericidal action upon photo-irradiation via reactive oxygen species (ROS) formation. In the present study, we focused on chemical composition and prooxidative profile of the extract. Liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) analysis showed that polyphenolic compounds including catechin monomers, dimers, trimers, and polyphenolic glucosides were contained. The polyphenol rich fraction used for the LC-ESI-MS analysis generated hydrogen peroxide (H2O2) upon photo-irradiation possibly initiated by photo-oxidation of phenolic hydroxyl group. That is, reduction of dissolved oxygen by proton-coupled electron transferred from the photo-oxidized phenolic hydroxyl group would form H2O2. The resultant H2O2 was then photolyzed to generate hydroxyl radical (•OH). The prooxidative profile of the extract in terms of •OH generation pattern upon photo-irradiation was similar to that of grape seed extract (GSE) as an authentic polyphenol product and (+)-catechin as a pure polyphenolic compound, and in all the three samples •OH generation could be retained during photo-irradiation for at least a couple of hours. The prooxidant activity of the photo-irradiated extract indicated by •OH yield was more potent than that of the photo-irradiated GSE and (+)-catechin, and this was well reflected in their bactericidal activity in which the photo-irradiated extract could kill the bacteria more efficiently than did the photo-irradiated GSE and (+)-catechin.

No MeSH data available.


Related in: MedlinePlus