title: Chromato-mass spectrometric identification of products of quercetin oxidation by atmospheric oxygen in aqueous solutions
metadata.name: dc.contributor.author
metadata.value: Pushkareva, Tatiana I.
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Zenkevich, Igor G.
metadata.lang: -
metadata.name: dc.date.accessioned
metadata.value: 2017-07-04T15:36:55Z
metadata.lang: -
metadata.name: dc.date.available
metadata.value: 2017-07-04T15:36:55Z
metadata.lang: -
metadata.name: dc.date.issued
metadata.value: 2017-03
metadata.lang: -
metadata.name: dc.identifier.citation
metadata.value: Pushkareva T. I., Zenkevich I. G. Chromato-mass spectrometric identification of products of quercetin oxidation by atmospheric oxygen in aqueous solutions. Vestnik SPbSU. Physics and Chemistry. 2017, vol. 4 (62), issue 1, pp. 59–79.
metadata.lang: en_GB
metadata.name: dc.identifier.uri
metadata.value: http://hdl.handle.net/11701/6656
metadata.lang: -
metadata.name: dc.description.abstract
metadata.value: The information about structures and formation mechanisms of oxidation products of such natural
  flavonoid as quercetin allows explaining the nature of its antioxidant activity remaining unexplored
  up to present. The aims of this paper imply the oxidation of quercetin by air oxygen in water alkaline
  solutions (pH = 8÷9) in presence of ethanol (to increase its solubility), mass-spectrometric
  analysis (HPLC-ES-MS-MS) of the reaction mixture and systematization of literature data on the
  oxidation products for comparing with our data. The retention indices of the oxidation products
  of quercetin have been determined in reversed-phase HPLC for the first time. It is confirmed
  that many of oxidation products of quercetin are stable only in solution and cannot be isolated
  after drying. In order to clarify the structures of some products, special experiments have been
  carried out. Thus, the replacement of ethanol with methanol in the composition of the reaction
  mixture can in some cases eliminate ethyl esters from further consideration and identify such
  products as 2-(3,4-dihydroxyphenyl)-2-oxoacetic acid and 2-oxo-2-(2,4,6-trihydroxyphenyl)acetic
  acid. To confirm the quinone structure of one of principal products of quercetin oxidation, the
  UV spectrum of the reaction mixture has been recorded and its reaction with hydroxylamine has
  been carried out. A large number of isomers have been revealed among the quercetin oxidation
  products. A method to distinguish them from the dimers formed in the mass spectrometer during
  the electrospray ionization process has been suggested. The two main oxidation mechanisms of
  quercetin discussed in the literature involve intermediate formation of compounds with the trivial
  names “depside” and “alfitonine”. Their joint presence in the product composition has been
  established, but their stability and lifetimes in solution are different. Refs 17. Tables 1.
metadata.lang: en_GB
metadata.name: dc.language.iso
metadata.value: ru
metadata.lang: en_GB
metadata.name: dc.publisher
metadata.value: St Petersburg State University
metadata.lang: en_GB
metadata.name: dc.relation.ispartofseries
metadata.value: Vestnik of St Petersburg University. Physics and Chemistry;Volume 4 (62); Issue 1
metadata.lang: -
metadata.name: dc.subject
metadata.value: quercetin
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: water solutions
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: oxidation
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: air oxygen
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: identification
metadata.lang: en_GB
metadata.name: dc.title
metadata.value: Chromato-mass spectrometric identification of products of quercetin oxidation by atmospheric oxygen in aqueous solutions
metadata.lang: en_GB
metadata.name: dc.type
metadata.value: Article
metadata.lang: en_GB
resources.filename: 08-Pushkareva.pdf
resources.url: https://dspace.spbu.ru/bitstream/11701/6656/1/08-Pushkareva.pdf
resources.format: Adobe PDF
resources.size: 856,56 kB