TY  - JOUR
AU  - Morina, Filis
AU  - Takahama, Umeo
AU  - Yamauchi, Ryo
AU  - Hirota, Sachiko
AU  - Veljović-Jovanović, Sonja
PY  - 2015
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/847
AB  - Foods of plant origin contain flavonoids. In the adzuki bean, (+)-catechin, quercetin 3-O-rutinoside (rutin), and quercetin 7-O-beta-D-glucopyranoside (Q7G) are the major flavonoids. During mastication of foods prepared from the adzuki bean, the flavonoids are mixed with saliva and swallowed into the stomach. Here we investigated the interactions between Q7G and (+)-catechin at pH 2, which may proceed in the stomach after the ingestion of foods prepared from the adzuki bean. Q7G reacted with nitrous acid producing nitric oxide ((NO)-N-center dot) and a glucoside of 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone. (+)-Catechin reacted with nitrous acid producing (NO)-N-center dot and 6,8-dinitrosocatechin. The production of the dinitrosocatechin was partly suppressed by Q7G, and the suppression resulted in the enhancement of Q7G oxidation. 6,8-Dinitrosocatechin reacted further with nitrous acid generating the o-quinone, and the quinone formation was effectively suppressed by Q7G. In the flavonoids investigated, the suppressive effect decreased in the order Q7G approximate to quercetin > kaempferol > quercetin 4'-O-glucoside > rutin. Essentially the same results were obtained when (-)-epicatechin was used instead of (+)-catechin. The results indicate that nitrous acid-induced formation of 6,8-dinitrosocatechins and the o-quinones can be suppressed by flavonols in the stomach, and that both a hydroxyl group at C3 and ortho-hydroxyl groups in the B-ring are required for efficient suppression.
PB  - Royal Soc Chemistry, Cambridge
T2  - Food & Function
T1  - Quercetin 7-O-glucoside suppresses nitrite-induced formation of dinitrosocatechins and their quinones in catechin/nitrite systems under stomach simulating conditions
EP  - 229
IS  - 1
SP  - 219
VL  - 6
DO  - 10.1039/c4fo00695j
ER  - 

@article{
author = "Morina, Filis and Takahama, Umeo and Yamauchi, Ryo and Hirota, Sachiko and Veljović-Jovanović, Sonja",
year = "2015",
abstract = "Foods of plant origin contain flavonoids. In the adzuki bean, (+)-catechin, quercetin 3-O-rutinoside (rutin), and quercetin 7-O-beta-D-glucopyranoside (Q7G) are the major flavonoids. During mastication of foods prepared from the adzuki bean, the flavonoids are mixed with saliva and swallowed into the stomach. Here we investigated the interactions between Q7G and (+)-catechin at pH 2, which may proceed in the stomach after the ingestion of foods prepared from the adzuki bean. Q7G reacted with nitrous acid producing nitric oxide ((NO)-N-center dot) and a glucoside of 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone. (+)-Catechin reacted with nitrous acid producing (NO)-N-center dot and 6,8-dinitrosocatechin. The production of the dinitrosocatechin was partly suppressed by Q7G, and the suppression resulted in the enhancement of Q7G oxidation. 6,8-Dinitrosocatechin reacted further with nitrous acid generating the o-quinone, and the quinone formation was effectively suppressed by Q7G. In the flavonoids investigated, the suppressive effect decreased in the order Q7G approximate to quercetin > kaempferol > quercetin 4'-O-glucoside > rutin. Essentially the same results were obtained when (-)-epicatechin was used instead of (+)-catechin. The results indicate that nitrous acid-induced formation of 6,8-dinitrosocatechins and the o-quinones can be suppressed by flavonols in the stomach, and that both a hydroxyl group at C3 and ortho-hydroxyl groups in the B-ring are required for efficient suppression.",
publisher = "Royal Soc Chemistry, Cambridge",
journal = "Food & Function",
title = "Quercetin 7-O-glucoside suppresses nitrite-induced formation of dinitrosocatechins and their quinones in catechin/nitrite systems under stomach simulating conditions",
pages = "229-219",
number = "1",
volume = "6",
doi = "10.1039/c4fo00695j"
}

Morina, F., Takahama, U., Yamauchi, R., Hirota, S.,& Veljović-Jovanović, S.. (2015). Quercetin 7-O-glucoside suppresses nitrite-induced formation of dinitrosocatechins and their quinones in catechin/nitrite systems under stomach simulating conditions. in Food & Function
Royal Soc Chemistry, Cambridge., 6(1), 219-229.
https://doi.org/10.1039/c4fo00695j

Morina F, Takahama U, Yamauchi R, Hirota S, Veljović-Jovanović S. Quercetin 7-O-glucoside suppresses nitrite-induced formation of dinitrosocatechins and their quinones in catechin/nitrite systems under stomach simulating conditions. in Food & Function. 2015;6(1):219-229.
doi:10.1039/c4fo00695j .

Morina, Filis, Takahama, Umeo, Yamauchi, Ryo, Hirota, Sachiko, Veljović-Jovanović, Sonja, "Quercetin 7-O-glucoside suppresses nitrite-induced formation of dinitrosocatechins and their quinones in catechin/nitrite systems under stomach simulating conditions" in Food & Function, 6, no. 1 (2015):219-229,
https://doi.org/10.1039/c4fo00695j . .

TY  - JOUR
AU  - Veljović-Jovanović, Sonja
AU  - Morina, Filis
AU  - Yamauchi, Ryo
AU  - Hirota, Sachiko
AU  - Takahama, Umeo
PY  - 2014
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/753
AB  - When foods that contain catechins and quercetin glycosides are ingested, quercetin glycosides are hydrolyzed to quercetin during mastication by hydrolytic enzymes derived from oral bacteria and the generated quercetin aglycone is mixed with catechins in saliva. The present study deals with the interactions between (+)-catechin and quercetin during their reactions with nitrous acid under the conditions simulating the gastric lumen. Nitrous acid reacted with (+)-catechin producing 6,8-dinitrosocatechin, and quercetin partially suppressed the dinitrosocatechin formation. Nitric oxide, which was produced by not only (+)-catechin/nitrous acid but also quercetin/nitrous acid systems, was used to produce 6,8-dinitrosocatechin. Furthermore, 6,8-dinitrosocatechin was oxidized by nitrous acid to the quinone form. The quinone formation was significantly suppressed by quercetin. Quercetin-dependent suppression of the above reactions accompanied the oxidation of quercetin, which was observed with the formation of 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone. Taking the above results into account, we proposed a possible mechanism of 6,8-dinitrosocatechin formation and discuss the importance of quercetin to prevent the quinone formation from 6,8-dinitrosocatechin in the gastric lumen, taking the interactions between quercetin and catechins into account.
PB  - Amer Chemical Soc, Washington
T2  - Journal of Agricultural and Food Chemistry
T1  - Interactions between (+)-Catechin and Quercetin during Their Oxidation by Nitrite under the Conditions Simulating the Stomach
EP  - 4959
IS  - 21
SP  - 4951
VL  - 62
DO  - 10.1021/jf500860s
ER  - 

@article{
author = "Veljović-Jovanović, Sonja and Morina, Filis and Yamauchi, Ryo and Hirota, Sachiko and Takahama, Umeo",
year = "2014",
abstract = "When foods that contain catechins and quercetin glycosides are ingested, quercetin glycosides are hydrolyzed to quercetin during mastication by hydrolytic enzymes derived from oral bacteria and the generated quercetin aglycone is mixed with catechins in saliva. The present study deals with the interactions between (+)-catechin and quercetin during their reactions with nitrous acid under the conditions simulating the gastric lumen. Nitrous acid reacted with (+)-catechin producing 6,8-dinitrosocatechin, and quercetin partially suppressed the dinitrosocatechin formation. Nitric oxide, which was produced by not only (+)-catechin/nitrous acid but also quercetin/nitrous acid systems, was used to produce 6,8-dinitrosocatechin. Furthermore, 6,8-dinitrosocatechin was oxidized by nitrous acid to the quinone form. The quinone formation was significantly suppressed by quercetin. Quercetin-dependent suppression of the above reactions accompanied the oxidation of quercetin, which was observed with the formation of 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone. Taking the above results into account, we proposed a possible mechanism of 6,8-dinitrosocatechin formation and discuss the importance of quercetin to prevent the quinone formation from 6,8-dinitrosocatechin in the gastric lumen, taking the interactions between quercetin and catechins into account.",
publisher = "Amer Chemical Soc, Washington",
journal = "Journal of Agricultural and Food Chemistry",
title = "Interactions between (+)-Catechin and Quercetin during Their Oxidation by Nitrite under the Conditions Simulating the Stomach",
pages = "4959-4951",
number = "21",
volume = "62",
doi = "10.1021/jf500860s"
}

Veljović-Jovanović, S., Morina, F., Yamauchi, R., Hirota, S.,& Takahama, U.. (2014). Interactions between (+)-Catechin and Quercetin during Their Oxidation by Nitrite under the Conditions Simulating the Stomach. in Journal of Agricultural and Food Chemistry
Amer Chemical Soc, Washington., 62(21), 4951-4959.
https://doi.org/10.1021/jf500860s

Veljović-Jovanović S, Morina F, Yamauchi R, Hirota S, Takahama U. Interactions between (+)-Catechin and Quercetin during Their Oxidation by Nitrite under the Conditions Simulating the Stomach. in Journal of Agricultural and Food Chemistry. 2014;62(21):4951-4959.
doi:10.1021/jf500860s .

Veljović-Jovanović, Sonja, Morina, Filis, Yamauchi, Ryo, Hirota, Sachiko, Takahama, Umeo, "Interactions between (+)-Catechin and Quercetin during Their Oxidation by Nitrite under the Conditions Simulating the Stomach" in Journal of Agricultural and Food Chemistry, 62, no. 21 (2014):4951-4959,
https://doi.org/10.1021/jf500860s . .