Direct and Indirect Antioxidant Activity of Polyphenol- and Isothiocyanate-Enriched Fractions from Moringa oleifera
مارس 15, 20174(α-l-rhamnosyloxy)-benzyl isothiocyanate, a bioactive phytochemical that attenuates secondary damage in an experimental model of spinal cord injury
مارس 26, 2017
Volume 172, 1 April 2015, Pages 423–427
Authors:
Matshediso PG1, Cukrowska E1, Chimuka L2.
1Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa.
2Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa. Electronic address: luke.chimuka@wits.ac.za.
Received 29 July 2013, Revised 20 June 2014, Accepted 10 September 2014, Available online 17 September 2014
Abstract
Pressurised hot water extraction (PHWE) is a “green” technology which can be used for the extraction of essential components in Moringa oleifera leaf extracts. The behaviour of three flavonols (myricetin, quercetin and kaempferol) and total phenolic content (TPC) in Moringa leaf powder were investigated at various temperatures using PHWE. The TPC of extracts from PHWE were investigated using two indicators. These are reducing activity and the radical scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH). Flavonols content in the PHWE extracts were analysed on high performance liquid chromatography with ultra violet (HPLC-UV) detection. The concentration of kaempferol and myricetin started decreasing at 150 °C while that of quercetin remained steady with extraction temperature. Optimum extraction temperature for flavonols and DPPH radical scavenging activity was found to be 100 °C. The TPC increased with temperature until 150 °C and then decreased while the reducing activity increased.
Copyright © 2014 Elsevier Ltd. All rights reserved.
KEYWORDS:
DPPH; Flavonols; Moringa oleifera; PHWE; Total phenolic content
Resource: https://www.ncbi.nlm.nih.gov/pubmed/25442573