Comparative studies on interactions of baicalein, baicalin and scutellarin with lysozyme.

The interactions of baicalein, baicalin and scutellarin with lysozyme (LYSO) were studied by fluorescence and UV spectroscopy. The results showed that all the three flavones can quench the fluorescence of LYSO via static quenching with the distance between the donor and acceptor less than 7 nm. The hydroxyl at B-ring gave flavones an advantage to binding with LYSO. Electrostatic forces played a major role in stabilizing baicalein-LYSO complex and baicalin-LYSO complex, whereas hydrophobic interactions in scutellarin-LYSO. Furthermore, the presence of pantothenic acid can increase the binding constant and the number of binding sites between flavones and LYSO.