Biochemical interaction of human hemoglobin with ionic liquids of noscapinoids: Spectroscopic and computational approach

In this work, we have developed noscapine based ionic liquids i.e., Noscapine (MeNOS) and 9-Bromonoscapine (MeBrNOS) as cation supported with bis(trifluoromethylsulfonyl)amide (NTf2-) as anion. We have reported the mechanism of binding interaction between noscapine based ILs and human hemoglobin (Hb) using various spectroscopic and computational techniques. The corresponding thermodynamics studies showed that the binding is exothermic in nature and major forces responsible for binding are Van der waals and hydrogen bonding interaction. The fluorescence spectra showed that the intensity of Hb decreases in the presence of [MeNOS]NTf2 and [MeBrNOS]NTf2 both shows static quenching. The secondary structural changes in Hb were observed and calculated by using CD spectroscopy. Molecular docking studies revealed that both the ILs show strong binding in beta 1 fragment of the tetrameric structure of Hb, but the binding of [MeNOS]NTf2 is relatively stronger than [MeBrNOS]NTf2 and the results are supported by MD simulations.

Automated summary

In this study, noscapine based ionic liquids, namely MeNOS and MeBrNOS, were developed as cations supported with NTf2- as an anion. The mechanism of binding interaction between the ionic liquids and human hemoglobin (Hb) was investigated using spectroscopic and computational techniques. The results indicated exothermic binding, primarily driven by Van der Waals and hydrogen bonding interactions. Both [MeNOS]NTf2 and [MeBrNOS]NTf2 caused a decrease in Hb intensity, suggesting static quenching. Molecular docking studies showed strong binding in the beta 1 fragment of Hb's tetrameric structure, with [MeNOS]NTf2 exhibiting stronger binding than [MeBrNOS]NTf2, corroborated by MD simulations.