The presence of NSAIDs may affect the binding capacity of serum albumin to the natural products hymecromone and umbelliferone.

The natural products 7-hydroxycoumarin (7HC) and 7-hydroxy-4-methylcoumarin (7H4MC), known as umbelliferone and hymecromone, respectively, are one of the simplest structural examples from coumarin's family, showing several biological activities. Bovine serum albumin (BSA) is the main model protein used in laboratory experiments to characterize the biophysical capacity of potential drugs to be carried until the target in the bloodstream. Thus, the interaction BSA:7HC and BSA:7H4MC was biophysically characterized by circular dichroism (CD), steady-state, and time-resolved fluorescence techniques combined with molecular docking calculations via cross-docking approach to better correlate with the biological medium. There is a ground-state association BSA:7HC/7H4MC, and the presence of the methyl group in the coumarin core did not change the binding affinity and trend to BSA significantly. However, comparing the obtained data with those reported to benzo-α-pyrone there is evidence that the incorporation of the hydroxyl group in the aromatic ring A of the coumarin core improves the binding affinity to albumin around 10-folds and changes the binding site from subdomain IIA to IIIA or IB. In addition, the presence of other drugs, e.g., naproxen or ketoprofen, might interfere with the binding capacity of 7HC and 7H4MC, resulting in perturbations on the residence time of some clinically used drugs in the bloodstream.