Peer-Reviewed Journal Details
Mandatory Fields
Dowling, S;Regan, F;Hughes, H
2010
October
Journal of Inorganic Biochemistry
The characterisation of structural and antioxidant properties of isoflavone metal chelates
Published
32 ()
Optional Fields
ELECTROSPRAY MASS-SPECTROMETRY BIOLOGICAL-ACTIVITY COPPER IONS FLAVONOIDS COMPLEXES IRON GENISTEIN QUERCETIN DAIDZEIN CELLS
104
1091
1098
Isoflavone metal chelates are of interest as isoflavones act as oestrogen mimics. Metal interactions may enhance isoflavones biological properties so understanding isoflavone metal chelation is important for the commercial application of isoflavones. This work aimed to determine if isoflavones, daidzein (4',7-dihydroxyisoflavone) and genistein (4',5,7-trihydroxyisoflavone) could chelate with metals as isoflavone chelates. Biochanin A (4'-methoxy-5,7-dihydroxyisoflavone) was also examined for it's ability to chelate with Cu(II) and Fe(III). This study found daidzein does not chelate with Cu(II) and Fe(III) but genistein and biochanin A chelate with a 1:2 M/L stoichiometry. The copper and iron chelates were synthesised and characterised by elemental analysis, FTIR, thermogravimetric analysis (TGA) and electrospray ionisation mass spectrometry (ESI-MS). These studies indicated a 1:2 M/L stoichiometry and suggested the isoflavones bind with the metals at the 4-keto and the 5-OH site. 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition assays showed that copper isoflavone chelates have higher antioxidant activity than free isoflavones while the iron isoflavone chelates showed pro-oxidant activity compared to the free isoflavone. Synergistic DPPH studies with 0.02 mM ascorbic acid revealed copper chelates exhibit reduced antioxidant activity versus free isoflavones whereas the iron chelates showed lower pro-oxidant activity except at 1.0 mM. (c) 2010 Elsevier Inc. All rights reserved.
NEW YORK
0162-0134
10.1016/j.jinorgbio.2010.06.007
Grant Details