Fe~(2+) and Co~(2+) improved the affinities of 7-hydroxyflavone, chrysin and quercetin for human serum albumin in vitro

摘要

Chrysin, 7-hydroxyflavone, and quercetin were studied for their affinities with human serum albumin (HSA) in the presence and absence of Fe~(2+) and Co~(2+). The fluorescence intensities of HSA decrease remarkably with increasing concentration of the tested flavonoids. Chrysin resulted in a blue-shift of the emission line λ _(em) of HSA from 336 to 330 nm whereas quercetin showed an obvious red-shift of λ _(em) from 336 to 347 nm. However, the extents of the λ _(em) shifts induced by flavonoids in the presence of mental ions are much bigger than those of the corresponding systems in the absence of mental ions. Fe~(2+) and Co~(2+) increased the quenching constants of the tested flavonoids for HSA by 12.4-48.1 and 15.0-66.7 %, respectively. The affinities of 7-hydroxyflavone, chrysin and quercetin for HSA increased by about 6.42, 7.38 and 0.62 %, respectively, in the presence of Fe~(2+). Co~(2+) increased the affinities of 7-hydroxyflavone, chrysin, and quercetin for HSA about 8.43, 7.86 and 11.73 %, respectively.