title: Chemical composition and antioxidant activity of ultrasound-assisted extract of the endemic plant Haberlea rhodopensis Friv.
abstract: The antioxidant capacity of extracts from leaves of Haberlea rhodopensis Friv. obtained by a highly efficient and simple method of the ultrasound-assisted extraction was investigated. The total polyphenolic content was determined spectrophotometrically using the Folin - Ciocalteu's phenol reagent and the polyphenols composition was analyzed by HPLC method. Antioxidant activity of the extract was evaluated as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2-azinobis-3 ethyl benxothiazoline-6-sulphonic acid (ABTS) cation decolorization activity assays and the ferric reducing/antioxidant power method (FRAP). The total phenolics of the extract were determined to be 148.71 ± 5.33 mg GAE on a dry weight basis. The HPLC analysis showed a large number of flavonoids and phenolic acids present in the ultrasound ethanol extract of H. rhodopensis. Results also revealed that the major flavonoids were luteolin (2730.18 μg/g DW), hesperidin (928.56 μg/g DW) and kaempferol (578.52 μg/g DW), whereas the most abundant phenolic acids identified in the extract were ferulic acid (630.48 μg/g DW) and sinapic acid (580.80 μg/g DW). DPPH(•) and ABTS(•+) values were 0.803 ± 0.007 and 0.769 ± 0.040 mmol TE/g DW, respectively and FRAP values were 1.362 ± 0.05 mmol TE/g DW.
authors.affiliation: Department of Biotechnology, University of Food Technologies, 26 Maritza Blvd., Plovdiv, 4002 Bulgaria.
authors.forename: Dasha
authors.initials: D
authors.lastname: Mihaylova
authors.affiliation: Department of Biotechnology, University of Food Technologies, 26 Maritza Blvd., Plovdiv, 4002 Bulgaria.
authors.forename: Mirena
authors.initials: M
authors.lastname: Ivanova
authors.affiliation: Department of Biotechnology, University of Food Technologies, 26 Maritza Blvd., Plovdiv, 4002 Bulgaria.
authors.forename: Slava
authors.initials: S
authors.lastname: Bahchevanska
authors.affiliation: Department of Biotechnology, University of Food Technologies, 26 Maritza Blvd., Plovdiv, 4002 Bulgaria.
authors.forename: Albert
authors.initials: A
authors.lastname: Krastanov
keywords: Haberlea rhodopensis; RP-HPLC; Radical scavenging activity; Ultrasound extraction
references.citation: Free Radic Biol Med. 1999 May;26(9-10):1231-7
references.pmid: 10381194
references.citation: J Agric Food Chem. 2000 Nov;48(11):5338-42
references.pmid: 11087483
references.citation: Methods Enzymol. 1999;299:15-27
references.pmid: 9916193
references.citation: Ultrason Sonochem. 2008 Mar;15(3):227-32
references.pmid: 17584518
references.citation: Ultrason Sonochem. 2005 Mar;12(4):295-300
references.pmid: 15501713
references.citation: Free Radic Biol Med. 1996;20(3):331-42
references.pmid: 8720903
references.citation: Ultrason Sonochem. 2010 Jan;17(1):61-5
references.pmid: 19497776
references.citation: Anal Biochem. 1996 Jul 15;239(1):70-6
references.pmid: 8660627
references.citation: Biotechnol Lett. 2011 Sep;33(9):1873-8
references.pmid: 21516312