Spectroscopic Analysis of the Interactions of Anthraquinone Derivatives (Alizarin,Alizarin-DA and Alizarin-DA-Fe) with Bovine Serum Albumin (BSA)

In this paper, three anthraquinones (alizarin (1,2-dihydroxy-9,10-anthraquinone), alizarin-DA (1,2-dihydroxy-9,10-anthraquinone-3-aminomethyl-N,N-diacetic acid) and alizarin-DA-Fe (1,2-dihydroxy-9,10-anthraquinone-3-aminomethyl-N,N-diacetate-ferric(III))) with a tricyclic anthraquinone planar structure are used as quenchers, to study their interaction with bovine serum albumin (BSA) molecules by fluorescence spectroscopy. The results show that these three anthraquinones can bind to BSA molecules efficiently but the stabilities decrease in the order alizarin, alizarin-DA and alizarin-DA-Fe. In addition, synchronous fluorescence spectroscopy indicates that the tryptophan (Trp) residues of BSA molecules are more accessible to alizarin and alizarin-DA than the tyrosine (Tyr) residues, but both have similar accessibility to alizarin-DA-Fe.