here - First Legume Society Conference (LSC1)

Book of Abstracts First Legume Society Conference 2013: A Legume Odyssey Novi Sad, Serbia, 9-11 May 2013
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Antioxidant characterization of phenolics from Trifolium scabrum L. aerial parts
Iwona Kowalska 1 , Łukasz Cieśla 2 , Anna Stochmal 1
1
Department of Biochemistry and Crop Quality, Institute of Soil Science and Plant Cultivation-State Research
Institute, Pulawy, Poland
2
Department of Inorganic Chemistry, Medical University, Lublin, Poland
Phenolic compounds have been recognized for many years as potent antioxidants. Isoflavones
are naturally occurring diphenolics found mainly in the legume family. Our preliminary analysis
suggest that Trifolium scabrum L. (rough clover) can be considered as very good source of these
compounds for commercial use. Fourteen isoflavones (aglycones or their glucosylated
derivatives) and two flavonol glucosides have been isolated and identified in aerial parts of
Trifolium scabrum L. Free radical scavenging potential of these substances has been assessed by
means of a simple benchtop TLC-DPPH • bioassay. Standard compounds and the analyzed
fraction were applied to aluminium-backed silica gel chromatographic plates. As the analyzed
extract contained compounds characterized with a wide range of polarity different
chromatographic systems were used to screen the free radical scavenging potential of individual
compounds. In this study following mobile phases were used: toluene-ethyl acetate-formic acid
(60:30:5, v/v/v) – for the least polar compounds; ethyl acetate-formic acid (95:5, v/v) – for the
medium polar constituents and chloroform-methanol-ethyl acetate-water (20:40:22:10, v/v/v/v)
for the most polar ones. TLC plates were immersed in freshly prepared 0.2% (w/v) methanolic
DPPH • solution. After removing DPPH • excess, plates were kept in the dark for 30 min and then
scanned by flatbed scanner. A comparison of the results was performed by an image processing
program ImageJ. Antiradical activity was shown by following compounds: 3’-hydroxydaidzein-7-
O-glc, isoquercitrin, calycosin-7-O-glc, kaempferol-3-O-glc (astragalin), daidzein, genistein and
biochanin A.
Acknowledgements
Participation in the First Legume Society Conference (LSC1) was sponsored by European Community 7 th
Framework Program project “Proficiency” (FP7REGPOT-2009-1-245751).
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