Comparison of 9-hydroxy-artemisinin with artemisinin: interaction with bovine hemoglobin

In this article, the UV–vis absorption, steady state/time resolved fluorescence spectroscopy and synchronous fluorescence, circular dichrosim (CD) spectroscopy are used to investigate the interaction of artemisinin (QHS) and 9-hydroxy-artemisinin (9-OH QHS) with BHb, respectively. The UV–vis studies present that QHS and 9-OH QHS can disturb the structure of bovine hemoglobin (BHb). Fluorescence data presents that the binding constant of QHS and 9-OH QHS with BHb complex at 298K is 4.32×105 and 5.98×105M−1. CD spectra indicate QHS and 9-OH QHS can change the conformation of BHb. The comparison results suggest that the binding of BHb with 9-OH QHS is more stable and stronger than QHS, which means the structure modification of 9-OH QHS is meaningful. •QHS and 9-OH QHS both induce the heme group of BHb•QHS and 9-OH QHS both can change the polarity of BHb•The interaction between BHb and 9-OH QHS is stronger than QHS