An investigation on structural aspects influencing product formation in enzymic and chemical oxidation of quercetin and related flavonols

Makris, Dimitris P.; Rossiter, John T.

doi:10.1016/s0308-8146(01)00333-8

Cited by 66 publications

(71 citation statements)

References 33 publications

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“…For both enzymes the same reaction products were detected indicating similar reaction mechanisms. In the case of quercetin, comparison of our spectra (isosbestic points) with these literature data suggests formation of o-quinones (Makris and Rossiter 2002).…”

Section: Enzyme Purification and Characterisationsupporting

confidence: 78%

“…However, in contrast to apigenin, luteolin has a 2-catechol function on the B ring. Interestingly, with the same number of hydroxyl substituents on the B ring, the substitution pattern seems to determine different reaction pathways (Makris and Rossiter 2002). Our results obtained with rutin indicate that glycosylation in the C3 position might negatively influence enzymatic oxidation when compared to the aglycon (quercetin).…”

Section: Enzyme Purification and Characterisationmentioning

confidence: 68%

“…Our results obtained with rutin indicate that glycosylation in the C3 position might negatively influence enzymatic oxidation when compared to the aglycon (quercetin). Similarly, lower oxidation rates were measured with a laccase from Polyporus versicolor for flavonols glycosylated at the C-3 position (Pickard and Westlake 1970) and for polyphenol oxidase and horseradish peroxidase (Makris and Rossiter 2002).…”

Section: Enzyme Purification and Characterisationmentioning

confidence: 98%

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Environmentally friendly bleaching of cotton using laccases

et al. 2005

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A new strain of Trametes hirsuta was found to oxidize various cotton flavonoids. Here we show that laccases of this organism were responsible for oxidation of the flavonoids morin, luteolin, rutin and quercetin. Out of two laccases produced by T. hirsuta (60.7 and 51.0 kDa) the more prominent 60.7 kDa laccase was purified and showed K m and k cat values of 75.5, 20.9 and 49.4 µM and 72.5, 96.3 and 32.7 s −1 , hours on ABTS, syringaldazide and DMP, respectively. Pretreatment of cotton with the T. hirsuta laccase resulted in a whiteness increase of 8.5%.

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Section: Enzyme Purification and Characterisationsupporting

confidence: 78%

Section: Enzyme Purification and Characterisationmentioning

confidence: 68%

Section: Enzyme Purification and Characterisationmentioning

confidence: 98%

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Environmentally friendly bleaching of cotton using laccases

et al. 2005

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“…There are literature data on the enzymatic (9)(10)(11)(12), chemical (11,(13)(14)(15), and electrochemical (16,17) oxidation of rutin, but its autoxidation was not studied in detail except in the study of the effect of thermal processing on rutin and quercetin in aqueous solutions (18). Considering the biological importance of both rutin and Mg(II) and Ca(II) ions we found it important to study the influence of Mg(II) and Ca(II) ions on the rutin autoxidation in a weakly alkaline aqueous solution as a model system.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Mg(II) and Ca(II) Ions on Rutin Autoxidation in Weakly Alkaline Aqueous Solutions

Zivanovic¹,

Nikolić²,

Nikolić³

2016

Acta Facultatis Medicae Naissensis

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Rutin (quercetin-3-O-rutinoside) is one of the most abundant bioflavonoids with various biological and pharmacological activities. Considering the ubiquitous presence of Mg(II) and Ca(II)ions in biological systems we decided to investigate their influence on the autoxidation of rutin in weakly alkaline aqueous solutions. Changes in UV-Vis spectra recorded during the rutin autoxidation in aqueous solution at pH 8.4 revealed that this process was very slow in the absence of metal ions. The presence of Mg(II) and, especially Ca(II) ion, increased the transformation rate of rutin. UV-Vis spectra recorded after prolonged autoxidation indicated the formation of humic acidlike products in the presence of Mg(II) and Ca(II) ions. Four new compounds formed during the initial stage of rutin autoxidation in the presence of Mg(II) and Ca(II) ions were detected by HPLC-DAD. Based on the analysis of their DAD UV-Vis spectra and comparison of their retention times with the retention time value for rutin, we concluded that the initial rutin transformation products were formed by the water addition on double bond in ring C and hydroxylation of ring B. A very small decrease of the initial rutin concentration (4%) was observed by HPLC-DAD in the absence of metal ions for the period of 90 minutes. However, rutin concentration decrease was much larger in the presence of Mg(II) and Ca(II) ions (14% and 24%, respectively). The more pronounced effect of Ca(II) ion on the rutin autoxidation may be explained by the stronger binding of Mg(II) ion to rutin and thus greater stabilizing effect on reaction intermediates caused by its higher ionic potential (charge/ionic radius ratio) in comparison to Ca(II) ion. The results of this study may contribute to the better understanding of interactions of Mg(II) and Ca(II) ions with natural phenolic antioxidants which are important for their various biological activities.Key words: rutin, autoxidation, magnesium, calcium O r i g i n a l a r t i c l e I NT ROD U CT I ONPhenolic compounds are ubiquitous in plants and their dietary intake has many beneficial effects on human health (1, 2). Rutin (quercetin-3-O-rutinoside), the glycoside between the flavonol quercetin and disaccharide rutinose (α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranose) (Figure 1) is one of the most abundant bioflavonoids with various biological and pharmacological activities (2, 3). Oxidation or/and autoxidation of natural phenolic compounds may have profound influence on their biological activity and stability of certain types of foods (4). Compounds having two or three vicinal hydroxyl groups on the same benzene ring are especially susceptible to autoxidation, and it was found that this process is mainly influenced by the pH value (4) and the presence of transition metal ions like Mn(II), Fe(II), and Cu(II) (5, 6) which are redox active and strongly enhance the autoxidation process. However, the influence of Mg(II) and Ca(II) ions on the autoxidation of natural phenolic compounds was studied less frequently (5, 7), although these t...

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“…Quercetin undergoes autoxidation-the nonenzymatic reaction with atmospheric oxygen. Also, it is known that one-electron oxidation of quercetin is catalyzed by different peroxidases like lactoperoxidase (LPO) [3] and horseradish peroxidase (HRP) [4][5][6][7] in the presence of H 2 O 2 .…”

Section: Introductionmentioning

confidence: 99%