Fluorescence spectrometric studies on the binding of puerarin to human serum albumin using warfarin, ibuprofen and digitoxin as site markers with the aid of chemometrics

► Puerarin can quench the fluorescence of human serum albumin (HSA). ► The HSA fluorescence is quenched by puerarin through a static quenching mechanism. ► The binding of puerarin to HSA is driven mainly by hydrophobic interaction. ► The parallel factor analysis confirms that puerarin is located in site I of HSA. ► The binding of puerarin to HSA induces changes in the secondary structure of HSA.