TY  - JOUR
AU  - Takahama, Umeo
AU  - Hirota, Sachiko
AU  - Morina, Filis
PY  - 2020
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1392
AB  - In Japan, adzuki bean is cooked with rice. During the cooking, the colour of rice becomes pale red. It is postulated that the red pigment is produced from procyanidins and that the ingestion of red rice causes the production of nitric oxide ((NO)-N-center dot) in the stomach by reacting with salivary nitrite. The increase in colour intensity accompanied the decrease in the amounts of procyanidins, suggesting the conversion of procyanidins into the red pigment during the cooking. In addition, the red pigment combined with rice strongly. The red-coloured rice produced (NO)-N-center dot by reacting with nitrite in artificial gastric juice, and the amounts were dependent on the contents of procyanidins and the equivalents. It is suggested that although adzuki procyanidins were oxidised during cooking with rice, procyanidins and the equivalents bound to rice still have the ability to produce bioactive (NO)-N-center dot in the stomach using nitrite in mixed whole saliva.
PB  - Taylor & Francis Ltd, Abingdon
T2  - International Journal of Food Sciences and Nutrition
T1  - Procyanidins in rice cooked with adzuki bean and their contribution to the reduction of nitrite to nitric oxide ((NO)-N-center dot) in artificial gastric juice
EP  - 73
IS  - 1
SP  - 63
VL  - 71
DO  - 10.1080/09637486.2019.1605338
ER  - 

@article{
author = "Takahama, Umeo and Hirota, Sachiko and Morina, Filis",
year = "2020",
abstract = "In Japan, adzuki bean is cooked with rice. During the cooking, the colour of rice becomes pale red. It is postulated that the red pigment is produced from procyanidins and that the ingestion of red rice causes the production of nitric oxide ((NO)-N-center dot) in the stomach by reacting with salivary nitrite. The increase in colour intensity accompanied the decrease in the amounts of procyanidins, suggesting the conversion of procyanidins into the red pigment during the cooking. In addition, the red pigment combined with rice strongly. The red-coloured rice produced (NO)-N-center dot by reacting with nitrite in artificial gastric juice, and the amounts were dependent on the contents of procyanidins and the equivalents. It is suggested that although adzuki procyanidins were oxidised during cooking with rice, procyanidins and the equivalents bound to rice still have the ability to produce bioactive (NO)-N-center dot in the stomach using nitrite in mixed whole saliva.",
publisher = "Taylor & Francis Ltd, Abingdon",
journal = "International Journal of Food Sciences and Nutrition",
title = "Procyanidins in rice cooked with adzuki bean and their contribution to the reduction of nitrite to nitric oxide ((NO)-N-center dot) in artificial gastric juice",
pages = "73-63",
number = "1",
volume = "71",
doi = "10.1080/09637486.2019.1605338"
}

Takahama, U., Hirota, S.,& Morina, F.. (2020). Procyanidins in rice cooked with adzuki bean and their contribution to the reduction of nitrite to nitric oxide ((NO)-N-center dot) in artificial gastric juice. in International Journal of Food Sciences and Nutrition
Taylor & Francis Ltd, Abingdon., 71(1), 63-73.
https://doi.org/10.1080/09637486.2019.1605338

Takahama U, Hirota S, Morina F. Procyanidins in rice cooked with adzuki bean and their contribution to the reduction of nitrite to nitric oxide ((NO)-N-center dot) in artificial gastric juice. in International Journal of Food Sciences and Nutrition. 2020;71(1):63-73.
doi:10.1080/09637486.2019.1605338 .

Takahama, Umeo, Hirota, Sachiko, Morina, Filis, "Procyanidins in rice cooked with adzuki bean and their contribution to the reduction of nitrite to nitric oxide ((NO)-N-center dot) in artificial gastric juice" in International Journal of Food Sciences and Nutrition, 71, no. 1 (2020):63-73,
https://doi.org/10.1080/09637486.2019.1605338 . .

TY  - JOUR
AU  - Morina, Filis
AU  - Hirota, Sachiko
AU  - Takahama, Umeo
PY  - 2020
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1299
AB  - Combining high-carbohydrate food with polyphenol-rich food is a possible way of producing slowly digestible starch with beneficial health properties. In Japan, non-glutinous and glutinous rice are cooked with adzuki bean and the colour of the cooked rice is pale red. In this article, we show that (1) the red colour of rice could be attributed to the oxidation of adzuki bean procyanidins, (2) pancreatin-induced starch digestion of the red-coloured non-glutinous rice was slower than white rice and (3) the digestion of amylose and potato starch but not amylopectin became slower by heating with procyanidin B2. Furthermore, the rate of starch digestion of red-coloured rice was not affected by nitrite treatment under simulated gastric conditions. The above results show that procyanidins could bind to amylose independent of the starch source by heating and could suppress starch digestion by alpha-amylase in the intestine.
PB  - Taylor & Francis Ltd, Abingdon
T2  - International Journal of Food Sciences and Nutrition
T1  - Contribution of amylose-procyanidin complexes to slower starch digestion of red-colored rice prepared by cooking with adzuki bean
EP  - 725
IS  - 6
SP  - 715
VL  - 71
DO  - 10.1080/09637486.2020.1719389
ER  - 

@article{
author = "Morina, Filis and Hirota, Sachiko and Takahama, Umeo",
year = "2020",
abstract = "Combining high-carbohydrate food with polyphenol-rich food is a possible way of producing slowly digestible starch with beneficial health properties. In Japan, non-glutinous and glutinous rice are cooked with adzuki bean and the colour of the cooked rice is pale red. In this article, we show that (1) the red colour of rice could be attributed to the oxidation of adzuki bean procyanidins, (2) pancreatin-induced starch digestion of the red-coloured non-glutinous rice was slower than white rice and (3) the digestion of amylose and potato starch but not amylopectin became slower by heating with procyanidin B2. Furthermore, the rate of starch digestion of red-coloured rice was not affected by nitrite treatment under simulated gastric conditions. The above results show that procyanidins could bind to amylose independent of the starch source by heating and could suppress starch digestion by alpha-amylase in the intestine.",
publisher = "Taylor & Francis Ltd, Abingdon",
journal = "International Journal of Food Sciences and Nutrition",
title = "Contribution of amylose-procyanidin complexes to slower starch digestion of red-colored rice prepared by cooking with adzuki bean",
pages = "725-715",
number = "6",
volume = "71",
doi = "10.1080/09637486.2020.1719389"
}

Morina, F., Hirota, S.,& Takahama, U.. (2020). Contribution of amylose-procyanidin complexes to slower starch digestion of red-colored rice prepared by cooking with adzuki bean. in International Journal of Food Sciences and Nutrition
Taylor & Francis Ltd, Abingdon., 71(6), 715-725.
https://doi.org/10.1080/09637486.2020.1719389

Morina F, Hirota S, Takahama U. Contribution of amylose-procyanidin complexes to slower starch digestion of red-colored rice prepared by cooking with adzuki bean. in International Journal of Food Sciences and Nutrition. 2020;71(6):715-725.
doi:10.1080/09637486.2020.1719389 .

Morina, Filis, Hirota, Sachiko, Takahama, Umeo, "Contribution of amylose-procyanidin complexes to slower starch digestion of red-colored rice prepared by cooking with adzuki bean" in International Journal of Food Sciences and Nutrition, 71, no. 6 (2020):715-725,
https://doi.org/10.1080/09637486.2020.1719389 . .

TY  - JOUR
AU  - Morina, Filis
AU  - Takahama, Umeo
AU  - Mojović, Miloš
AU  - Popovic-Bijelic, Ana
AU  - Veljović-Jovanović, Sonja
PY  - 2016
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/939
AB  - Catechins are transformed into dinitrosocatechins (diNOcats) and then oxidized to the quinones by salivary nitrite under conditions simulating the stomach. This manuscript deals with formation of stable radicals in the NO group of diNOcat during nitrite-induced oxidation of (+)-catechin and diNOcat at pH 2. We postulated two mechanisms for the stable radical formation; one is nitrous acid-induced oxidation of diNOcat in the A-ring, and the other intermolecular charge transfer from the A-ring of diNOcat and/or diNOcat quinone to the quinone moiety of the B-ring of diNOcat quinone. In addition, an unstable phenoxyl radical, which might be transformed into quinone, was also produced, accompanying the formation of the stable radical on the NO group. Taking the above results into account, we mainly focus on the adverse effects of the radicals and quinone, which may be produced from (+)-catechin in the stomach under the conditions of high salivary nitrite concentrations.
PB  - Elsevier Sci Ltd, Oxford
T2  - Food Chemistry
T1  - Formation of stable radicals in catechin/nitrous acid systems: Participation of dinitrosocatechin
EP  - 1122
SP  - 1116
VL  - 194
DO  - 10.1016/j.foodchem.2015.08.081
ER  - 

@article{
author = "Morina, Filis and Takahama, Umeo and Mojović, Miloš and Popovic-Bijelic, Ana and Veljović-Jovanović, Sonja",
year = "2016",
abstract = "Catechins are transformed into dinitrosocatechins (diNOcats) and then oxidized to the quinones by salivary nitrite under conditions simulating the stomach. This manuscript deals with formation of stable radicals in the NO group of diNOcat during nitrite-induced oxidation of (+)-catechin and diNOcat at pH 2. We postulated two mechanisms for the stable radical formation; one is nitrous acid-induced oxidation of diNOcat in the A-ring, and the other intermolecular charge transfer from the A-ring of diNOcat and/or diNOcat quinone to the quinone moiety of the B-ring of diNOcat quinone. In addition, an unstable phenoxyl radical, which might be transformed into quinone, was also produced, accompanying the formation of the stable radical on the NO group. Taking the above results into account, we mainly focus on the adverse effects of the radicals and quinone, which may be produced from (+)-catechin in the stomach under the conditions of high salivary nitrite concentrations.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Food Chemistry",
title = "Formation of stable radicals in catechin/nitrous acid systems: Participation of dinitrosocatechin",
pages = "1122-1116",
volume = "194",
doi = "10.1016/j.foodchem.2015.08.081"
}

Morina, F., Takahama, U., Mojović, M., Popovic-Bijelic, A.,& Veljović-Jovanović, S.. (2016). Formation of stable radicals in catechin/nitrous acid systems: Participation of dinitrosocatechin. in Food Chemistry
Elsevier Sci Ltd, Oxford., 194, 1116-1122.
https://doi.org/10.1016/j.foodchem.2015.08.081

Morina F, Takahama U, Mojović M, Popovic-Bijelic A, Veljović-Jovanović S. Formation of stable radicals in catechin/nitrous acid systems: Participation of dinitrosocatechin. in Food Chemistry. 2016;194:1116-1122.
doi:10.1016/j.foodchem.2015.08.081 .

Morina, Filis, Takahama, Umeo, Mojović, Miloš, Popovic-Bijelic, Ana, Veljović-Jovanović, Sonja, "Formation of stable radicals in catechin/nitrous acid systems: Participation of dinitrosocatechin" in Food Chemistry, 194 (2016):1116-1122,
https://doi.org/10.1016/j.foodchem.2015.08.081 . .

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 . .

TY  - JOUR
AU  - Kukavica, Biljana
AU  - Mojović, Miloš
AU  - Vučinić, Željko
AU  - Maksimović, Vuk
AU  - Takahama, Umeo
AU  - Veljović-Jovanović, Sonja
PY  - 2009
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/368
AB  - The hydroxyl radical produced in the apoplast has been demonstrated to facilitate cell wall loosening during cell elongation. Cell wall-bound peroxidases (PODs) have been implicated in hydroxyl radical formation. For this mechanism, the apoplast or cell walls should contain the electron donors for (i) H2O2 formation from dioxygen; and (ii) the POD-catalyzed reduction of H2O2 to the hydroxyl radical. The aim of the work was to identify the electron donors in these reactions. In this report, hydroxyl radical (OH) generation in the cell wall isolated from pea roots was detected in the absence of any exogenous reductants, suggesting that the plant cell wall possesses the capacity to generate OH in situ. Distinct POD and Mn-superoxide dismutase (Mn-SOD) isoforms different from other cellular isoforms were shown by native gel electrophoresis to be preferably bound to the cell walls. Electron paramagnetic resonance (EPR) spectroscopy of cell wall isolates containing the spin-trapping reagent, 5-diethoxyphosphoryl-5-methyl-1-pyrroline-N-oxide (DEPMPO), was used for detection of and differentiation between OH and the superoxide radical (O-2). The data obtained using POD inhibitors confirmed that tightly bound cell wall PODs are involved in DEPMPOOH adduct formation. A decrease in DEPMPOOH adduct formation in the presence of H2O2 scavengers demonstrated that this hydroxyl radical was derived from H2O2. During the generation of OH, the concentration of quinhydrone structures (as detected by EPR spectroscopy) increased, suggesting that the H2O2 required for the formation of OH in isolated cell walls is produced during the reduction of O-2 by hydroxycinnamic acids. Cell wall isolates in which the proteins have been denaturated (including the endogenous POD and SOD) did not produce OH. Addition of exogenous H2O2 again induced the production of OH, and these were shown to originate from the Fenton reaction with tightly bound metal ions. However, the appearance of the DEPMPOOOH adduct could also be observed, due to the production of O-2 when endogenous SOD has been inactivated. Also, O-2 was converted to OH in an in vitro horseradish peroxidase (HRP)H2O2 system to which exogenous SOD has been added. Taken together with the discovery of the cell wall-bound Mn-SOD isoform, these results support the role of such a cell wall-bound SOD in the formation of OH jointly with the cell wall-bound POD. According to the above findings, it seems that the hydroxycinnamic acids from the cell wall, acting as reductants, contribute to the formation of H2O2 in the presence of O-2 in an autocatalytic manner, and that POD and Mn-SOD coupled together generate OH from such H2O2.
PB  - Oxford Univ Press, Oxford
T2  - Plant and Cell Physiology
T1  - Generation of Hydroxyl Radical in Isolated Pea Root Cell Wall, and the Role of Cell Wall-Bound Peroxidase, Mn-SOD and Phenolics in Their Production
EP  - 317
IS  - 2
SP  - 304
VL  - 50
DO  - 10.1093/pcp/pcn199
ER  - 

@article{
author = "Kukavica, Biljana and Mojović, Miloš and Vučinić, Željko and Maksimović, Vuk and Takahama, Umeo and Veljović-Jovanović, Sonja",
year = "2009",
abstract = "The hydroxyl radical produced in the apoplast has been demonstrated to facilitate cell wall loosening during cell elongation. Cell wall-bound peroxidases (PODs) have been implicated in hydroxyl radical formation. For this mechanism, the apoplast or cell walls should contain the electron donors for (i) H2O2 formation from dioxygen; and (ii) the POD-catalyzed reduction of H2O2 to the hydroxyl radical. The aim of the work was to identify the electron donors in these reactions. In this report, hydroxyl radical (OH) generation in the cell wall isolated from pea roots was detected in the absence of any exogenous reductants, suggesting that the plant cell wall possesses the capacity to generate OH in situ. Distinct POD and Mn-superoxide dismutase (Mn-SOD) isoforms different from other cellular isoforms were shown by native gel electrophoresis to be preferably bound to the cell walls. Electron paramagnetic resonance (EPR) spectroscopy of cell wall isolates containing the spin-trapping reagent, 5-diethoxyphosphoryl-5-methyl-1-pyrroline-N-oxide (DEPMPO), was used for detection of and differentiation between OH and the superoxide radical (O-2). The data obtained using POD inhibitors confirmed that tightly bound cell wall PODs are involved in DEPMPOOH adduct formation. A decrease in DEPMPOOH adduct formation in the presence of H2O2 scavengers demonstrated that this hydroxyl radical was derived from H2O2. During the generation of OH, the concentration of quinhydrone structures (as detected by EPR spectroscopy) increased, suggesting that the H2O2 required for the formation of OH in isolated cell walls is produced during the reduction of O-2 by hydroxycinnamic acids. Cell wall isolates in which the proteins have been denaturated (including the endogenous POD and SOD) did not produce OH. Addition of exogenous H2O2 again induced the production of OH, and these were shown to originate from the Fenton reaction with tightly bound metal ions. However, the appearance of the DEPMPOOOH adduct could also be observed, due to the production of O-2 when endogenous SOD has been inactivated. Also, O-2 was converted to OH in an in vitro horseradish peroxidase (HRP)H2O2 system to which exogenous SOD has been added. Taken together with the discovery of the cell wall-bound Mn-SOD isoform, these results support the role of such a cell wall-bound SOD in the formation of OH jointly with the cell wall-bound POD. According to the above findings, it seems that the hydroxycinnamic acids from the cell wall, acting as reductants, contribute to the formation of H2O2 in the presence of O-2 in an autocatalytic manner, and that POD and Mn-SOD coupled together generate OH from such H2O2.",
publisher = "Oxford Univ Press, Oxford",
journal = "Plant and Cell Physiology",
title = "Generation of Hydroxyl Radical in Isolated Pea Root Cell Wall, and the Role of Cell Wall-Bound Peroxidase, Mn-SOD and Phenolics in Their Production",
pages = "317-304",
number = "2",
volume = "50",
doi = "10.1093/pcp/pcn199"
}

Kukavica, B., Mojović, M., Vučinić, Ž., Maksimović, V., Takahama, U.,& Veljović-Jovanović, S.. (2009). Generation of Hydroxyl Radical in Isolated Pea Root Cell Wall, and the Role of Cell Wall-Bound Peroxidase, Mn-SOD and Phenolics in Their Production. in Plant and Cell Physiology
Oxford Univ Press, Oxford., 50(2), 304-317.
https://doi.org/10.1093/pcp/pcn199

Kukavica B, Mojović M, Vučinić Ž, Maksimović V, Takahama U, Veljović-Jovanović S. Generation of Hydroxyl Radical in Isolated Pea Root Cell Wall, and the Role of Cell Wall-Bound Peroxidase, Mn-SOD and Phenolics in Their Production. in Plant and Cell Physiology. 2009;50(2):304-317.
doi:10.1093/pcp/pcn199 .

Kukavica, Biljana, Mojović, Miloš, Vučinić, Željko, Maksimović, Vuk, Takahama, Umeo, Veljović-Jovanović, Sonja, "Generation of Hydroxyl Radical in Isolated Pea Root Cell Wall, and the Role of Cell Wall-Bound Peroxidase, Mn-SOD and Phenolics in Their Production" in Plant and Cell Physiology, 50, no. 2 (2009):304-317,
https://doi.org/10.1093/pcp/pcn199 . .

TY  - JOUR
AU  - Veljović-Jovanović, Sonja
AU  - Milovanović, L.
AU  - Oniki, T.
AU  - Takahama, Umeo
PY  - 1999
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/48
AB  - An oxidative detoxification of sulfite, which originates from sulfur dioxide taken up into a leaf, has not yet been fully understood. In this study, we discuss that redox reactions between sulfite and H2O2 have an important role for the detoxification of sulfite. Sulfite was oxidized by H2O2 and during the redox reaction, oxygen consumption was observed. The oxygen consumption was partially inhibited by superoxide dismutase, indicating that O-2(-) is generated during the redox reaction. Oxidation of sulfite by H2O2 was also observed in the presence of ascorbic acid, and during the oxidation, no significant oxidation of ascorbic acid and no consumption of oxygen were observed. Sulfite inhibited catalase of cell-free extracts of spinach, pea and broad bean leaves. These results suggest that when leaves are fumigated with SO2 in the light, catalase is inactivated resulting in the accumulation of H2O2 in leaves, which can oxidize sulfite without generating active oxygen species like O-2(-) as long as ascorbate is present in leaves.
PB  - Harwood Academic Publishers GmbH
T2  - Free Radical Research
T1  - Inhibition of catalase by sulfite and oxidation of sulfite by H2O2 cooperating with ascorbic acid
EP  - S57
IS  - SUPPL.
SP  - S51
VL  - 31
DO  - 10.1080/10715769900301321
ER  - 

@article{
author = "Veljović-Jovanović, Sonja and Milovanović, L. and Oniki, T. and Takahama, Umeo",
year = "1999",
abstract = "An oxidative detoxification of sulfite, which originates from sulfur dioxide taken up into a leaf, has not yet been fully understood. In this study, we discuss that redox reactions between sulfite and H2O2 have an important role for the detoxification of sulfite. Sulfite was oxidized by H2O2 and during the redox reaction, oxygen consumption was observed. The oxygen consumption was partially inhibited by superoxide dismutase, indicating that O-2(-) is generated during the redox reaction. Oxidation of sulfite by H2O2 was also observed in the presence of ascorbic acid, and during the oxidation, no significant oxidation of ascorbic acid and no consumption of oxygen were observed. Sulfite inhibited catalase of cell-free extracts of spinach, pea and broad bean leaves. These results suggest that when leaves are fumigated with SO2 in the light, catalase is inactivated resulting in the accumulation of H2O2 in leaves, which can oxidize sulfite without generating active oxygen species like O-2(-) as long as ascorbate is present in leaves.",
publisher = "Harwood Academic Publishers GmbH",
journal = "Free Radical Research",
title = "Inhibition of catalase by sulfite and oxidation of sulfite by H2O2 cooperating with ascorbic acid",
pages = "S57-S51",
number = "SUPPL.",
volume = "31",
doi = "10.1080/10715769900301321"
}

Veljović-Jovanović, S., Milovanović, L., Oniki, T.,& Takahama, U.. (1999). Inhibition of catalase by sulfite and oxidation of sulfite by H2O2 cooperating with ascorbic acid. in Free Radical Research
Harwood Academic Publishers GmbH., 31(SUPPL.), S51-S57.
https://doi.org/10.1080/10715769900301321

Veljović-Jovanović S, Milovanović L, Oniki T, Takahama U. Inhibition of catalase by sulfite and oxidation of sulfite by H2O2 cooperating with ascorbic acid. in Free Radical Research. 1999;31(SUPPL.):S51-S57.
doi:10.1080/10715769900301321 .

Veljović-Jovanović, Sonja, Milovanović, L., Oniki, T., Takahama, Umeo, "Inhibition of catalase by sulfite and oxidation of sulfite by H2O2 cooperating with ascorbic acid" in Free Radical Research, 31, no. SUPPL. (1999):S51-S57,
https://doi.org/10.1080/10715769900301321 . .

TY  - JOUR
AU  - Veljović-Jovanović, Sonja
AU  - Oniki, T
AU  - Takahama, Umeo
PY  - 1998
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/40
AB  - The aim of the present study is to detect the monodehydroascorbic acid (MDA) radical in broad bean (Vicia faba L.) leaves which were treated by vacuum-infiltration in Na2SO3 solution and subsequent centrifugation (sulfite-treated leaves). When sulfite-treated leaves were illuminated with white light, the electron spin resonance (ESR) signal of MDA radical was observed. The level of the MDA radical depended on the concentration of sulfite that was used for vacuum-infiltration and on the light intensity of illumination. The formation of the MDA radical in sulfite-treated leaves was inhibited by DCMU or by replacement of air with N-2. Glycolaldehyde also inhibited the formation of MDA radical in sulfite-treated leaves. Catalase activity was decreased by the sulfite treatment without affecting significantly the activities of ascorbate peroxidase (AA-POX) and of peroxidase which preferentially oxidizes phenolics (PhOH-POX). From these results, we conclude that the formation of the MDA radical in sulfite-treated leaves is catalyzed by peroxidases using the H2O2 which is generated by photorespiration and the Mehler reaction.
PB  - Japanese Soc Plant Physiologists, Kyoto
T2  - Plant and Cell Physiology
T1  - Detection of monodehydroascorbic acid radical in sulfite-treated leaves and mechanism of its formation
EP  - 1208
IS  - 11
SP  - 1203
VL  - 39
DO  - 10.1093/oxfordjournals.pcp.a029321
ER  - 

@article{
author = "Veljović-Jovanović, Sonja and Oniki, T and Takahama, Umeo",
year = "1998",
abstract = "The aim of the present study is to detect the monodehydroascorbic acid (MDA) radical in broad bean (Vicia faba L.) leaves which were treated by vacuum-infiltration in Na2SO3 solution and subsequent centrifugation (sulfite-treated leaves). When sulfite-treated leaves were illuminated with white light, the electron spin resonance (ESR) signal of MDA radical was observed. The level of the MDA radical depended on the concentration of sulfite that was used for vacuum-infiltration and on the light intensity of illumination. The formation of the MDA radical in sulfite-treated leaves was inhibited by DCMU or by replacement of air with N-2. Glycolaldehyde also inhibited the formation of MDA radical in sulfite-treated leaves. Catalase activity was decreased by the sulfite treatment without affecting significantly the activities of ascorbate peroxidase (AA-POX) and of peroxidase which preferentially oxidizes phenolics (PhOH-POX). From these results, we conclude that the formation of the MDA radical in sulfite-treated leaves is catalyzed by peroxidases using the H2O2 which is generated by photorespiration and the Mehler reaction.",
publisher = "Japanese Soc Plant Physiologists, Kyoto",
journal = "Plant and Cell Physiology",
title = "Detection of monodehydroascorbic acid radical in sulfite-treated leaves and mechanism of its formation",
pages = "1208-1203",
number = "11",
volume = "39",
doi = "10.1093/oxfordjournals.pcp.a029321"
}

Veljović-Jovanović, S., Oniki, T.,& Takahama, U.. (1998). Detection of monodehydroascorbic acid radical in sulfite-treated leaves and mechanism of its formation. in Plant and Cell Physiology
Japanese Soc Plant Physiologists, Kyoto., 39(11), 1203-1208.
https://doi.org/10.1093/oxfordjournals.pcp.a029321

Veljović-Jovanović S, Oniki T, Takahama U. Detection of monodehydroascorbic acid radical in sulfite-treated leaves and mechanism of its formation. in Plant and Cell Physiology. 1998;39(11):1203-1208.
doi:10.1093/oxfordjournals.pcp.a029321 .

Veljović-Jovanović, Sonja, Oniki, T, Takahama, Umeo, "Detection of monodehydroascorbic acid radical in sulfite-treated leaves and mechanism of its formation" in Plant and Cell Physiology, 39, no. 11 (1998):1203-1208,
https://doi.org/10.1093/oxfordjournals.pcp.a029321 . .

TY  - JOUR
AU  - Takahama, Umeo
AU  - Veljović-Jovanović, Sonja
AU  - Heber, U.
PY  - 1992
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/30
AB  - After SO2 has entered leaves of spinach (Spinacia oleracea) through open stomata and been hydrated in the aqueous phase of cell walls, the sulfite formed can be oxidized to sulfate by an apoplastic peroxidase that is normally involved in phenol oxidation. The oxidation of sulfite is competitive with the oxidation of phenolics. During sulfite oxidation, the peroxidase is inhibited. In the absence of ascorbate, which is a normal constituent of the aqueous phase of the apoplast, peroxidative sulfite oxidation facilitates fast additional sulfite oxidation by a radical chain reaction. By scavenging radicals, ascorbate inhibits chain initiation and sulfite oxidation. Even after exposure of leaves to high concentrations of SO2, which inhibited photosynthesis, the redox state of ascorbate remained almost unaltered in the apoplastic space of the leaves. It is concluded that the oxidative detoxification of SO2 in the apoplast outside the cells is slow. Its rate depends on the rate of apoplastic hydrogen peroxide generation and on the steady-state apoplastic concentrations of phenolics and sulfite. The affinity of the peroxidase for phenolics is higher than that for sulfite.
PB  - American Society of Plant Biologists
T2  - Plant Physiology
T1  - Effects of the air pollutant SO2 on leaves: Inhibition of sulfite oxidation in the apoplast by ascorbate and of apoplastic peroxidase by sulfite
EP  - 266
IS  - 1
SP  - 261
VL  - 100
DO  - 10.1104/pp.100.1.261
ER  - 

@article{
author = "Takahama, Umeo and Veljović-Jovanović, Sonja and Heber, U.",
year = "1992",
abstract = "After SO2 has entered leaves of spinach (Spinacia oleracea) through open stomata and been hydrated in the aqueous phase of cell walls, the sulfite formed can be oxidized to sulfate by an apoplastic peroxidase that is normally involved in phenol oxidation. The oxidation of sulfite is competitive with the oxidation of phenolics. During sulfite oxidation, the peroxidase is inhibited. In the absence of ascorbate, which is a normal constituent of the aqueous phase of the apoplast, peroxidative sulfite oxidation facilitates fast additional sulfite oxidation by a radical chain reaction. By scavenging radicals, ascorbate inhibits chain initiation and sulfite oxidation. Even after exposure of leaves to high concentrations of SO2, which inhibited photosynthesis, the redox state of ascorbate remained almost unaltered in the apoplastic space of the leaves. It is concluded that the oxidative detoxification of SO2 in the apoplast outside the cells is slow. Its rate depends on the rate of apoplastic hydrogen peroxide generation and on the steady-state apoplastic concentrations of phenolics and sulfite. The affinity of the peroxidase for phenolics is higher than that for sulfite.",
publisher = "American Society of Plant Biologists",
journal = "Plant Physiology",
title = "Effects of the air pollutant SO2 on leaves: Inhibition of sulfite oxidation in the apoplast by ascorbate and of apoplastic peroxidase by sulfite",
pages = "266-261",
number = "1",
volume = "100",
doi = "10.1104/pp.100.1.261"
}

Takahama, U., Veljović-Jovanović, S.,& Heber, U.. (1992). Effects of the air pollutant SO2 on leaves: Inhibition of sulfite oxidation in the apoplast by ascorbate and of apoplastic peroxidase by sulfite. in Plant Physiology
American Society of Plant Biologists., 100(1), 261-266.
https://doi.org/10.1104/pp.100.1.261

Takahama U, Veljović-Jovanović S, Heber U. Effects of the air pollutant SO2 on leaves: Inhibition of sulfite oxidation in the apoplast by ascorbate and of apoplastic peroxidase by sulfite. in Plant Physiology. 1992;100(1):261-266.
doi:10.1104/pp.100.1.261 .

Takahama, Umeo, Veljović-Jovanović, Sonja, Heber, U., "Effects of the air pollutant SO2 on leaves: Inhibition of sulfite oxidation in the apoplast by ascorbate and of apoplastic peroxidase by sulfite" in Plant Physiology, 100, no. 1 (1992):261-266,
https://doi.org/10.1104/pp.100.1.261 . .