Interactive Profile between 1,4-Naphthoquinone Derivatives and Human Serum Albumin

Abstract

The interactive profile between four 1,4-naphthoquinone derivatives (1-4) and human serum albumin (HSA) was studied by spectroscopic techniques and in silico calculations. The bimolecular quenching rate constant (kq ca. 1012 L mol-1 s-1) and the time-resolved fluorescence decays indicated a static fluorescence quenching mechanism. Thus, there is a spontaneous ground-state association, and based on both Stern-Volmer, modified Stern-Volmer, and van’t Hoff approaches, the association is moderate mainly driven by hydrophobic forces. The circular dichroism (CD) analysis indicated that until the proportion albumin:compound of 1:8 there is a weak perturbation on the structural content of albumin, while molecular docking results suggested subdomain IIA (site I), a positive electrostatic pocket, as the main binding site. Overall, even though the hydrogen atom replacement by methyl, fluorine, or chlorine atoms in the para position of the aromatic ring in the benzo[g]chromene-5,10-dione moiety changes the lipophilicity, it does not change the binding profile to HSA.

Revisiting and Updating the Interaction between Human Serum Albumin and the Non-Steroidal Anti-Inflammatory Drugs Ketoprofen and Ketorolac

“…Figure 3A,B depict the steady-state fluorescence emission of HSA without and upon the successive additions of KTF and KTL, respectively. Since NSAIDs did not cause any shift in the fluorescence spectra, the binding does not perturb the microenvironment around the fluorophores of albumin [51]. The steady-state fluorescence emission of NSAIDs was recorded, and no fluorescence was detected within the region corresponding to the albumin fluorescence emission (320-500 nm range).…”