Publication detail

Assessment of antioxidant properties of different types of herbs by EPR and UV-VIS spectroscopy

BUTOROVÁ, L. POLOVKA, M. TOBOLKOVÁ, B. VÍTOVÁ, E.

Original Title

Type

abstract

Language

English

Original Abstract

There is an increasing interest in complex characterization of medical herbs and herb products and isolation of their main active components including antioxidants. The first step of effective isolation of antioxidants from herbs is the extraction, which must be fast, simple and inexpensive, but also sensitive to respective bioactive components, environmental friendly and easy to automate. The aim of this contribution was to perform the assessment of antioxidant properties of various types of herbs commonly available in this territory in different extraction media by using modern spectroscopic techniques. Selected herbs were extracted in four different solvents, i.e., distilled water, 50% ethanol, 50% acetone and dimethylsulfoxide and subsequently analysed by EPR and UV-VIS NIR spectroscopy involving several assays. Total content of polyphenols (TPC), total content of flavonoids (TFC) and color characteristic using the CIE L*a*b* system were determined using the UV-VIS-NIR spectroscopy. Antioxidant activity of extracts was tested by 2,2´-azino-bis(3-ethyl-benzothiazoline-6-sulphonic acid cation radical (ABTS•+) assay. The capability of extracts components to terminate the hydroxyl radicals (•OH) generated by chemical reaction directly in the experimental system via thermal decomposition of potassium persulfate (K2S2O8) radical initiator in the presence of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as spin trap was also investigated. Obtained results clearly proved the solvent-dependent isolation of antioxidants, mainly influenced by the solvent polarity and the character of isolated compounds. Additional experiments are in progress in order to correlate the results of antioxidant activity assays with the composition of the investigated medical herbs determined by LC and mineral content, evaluated by ICP-OES.

Keywords

medical herbs, antioxidant properties, EPR, UV-VIS

Authors

BUTOROVÁ, L.; POLOVKA, M.; TOBOLKOVÁ, B.; VÍTOVÁ, E.

Released

2. 9. 2015

Publisher

Brno University of Technology, Faculty of Chemistry

Location

Brno

ISBN

978-80-214-5228-2

Book

Chemistry & Life 2015 - Book of Abstracts

Edition

Edition number

Pages from

Pages to

Pages count

200

BibTex

@misc{BUT116426,
  author="Lenka {Burdějová} and Martin {Polovka} and Blanka {Tobolková} and Eva {Vítová}",
  title="Assessment of antioxidant properties of different types of herbs by EPR and UV-VIS spectroscopy",
  booktitle="Chemistry & Life 2015 - Book of Abstracts",
  year="2015",
  series="1.",
  edition="1.",
  pages="96--96",
  publisher="Brno University of Technology, Faculty of Chemistry",
  address="Brno",
  isbn="978-80-214-5228-2",
  note="abstract"
}