Future studies should focus on characterizing catechol transformation products under physiological conditions, particularly in scenarios involving protein modification. Isolated or synthesized products could then be evaluated in structure-activity relationship studies to identify pharmacologically active metabolites, paving the way for rational drug or prodrug design to optimize therapeutic outcomes. immediately after preparation (t = 0 h) and distinct browning of 15.6 mM catechol after 96 h of incubation at 37 °C in A) 50 mM tris(hydroxymethyl)aminomethane (Tris) buffer (pH 7.8) and 50 mM sodium phosphate (Pi) buffer (pH 7.8), C) 15 mM glycine (Gly; unbuffered and in 50 mM Pi, pH 7.8), E) 20 mg/mL bovine serum albumin (BSA; unbuffered and in 50 mM Pi, pH 7.8), and G) 20 mg/mL skim milk (unbuffered and in 50 mM Pi, pH 7.8). UV-visible absorbance spectra of 15.6 mM catechol at t = 0 h and t = 96 h for B) Tris and Pi buffers, D) unbuffered and Pi-buffered Gly, F) unbuffered and Pi-buffered BSA, and H) unbuffered and Pi-buffered skim milk. For catechol in Pi and Tris buffers alone, the 96-h samples were diluted to one-half of their original concentration to remain within the instrument's quantifiable range for spectral analysis, while catechol incubated with Gly, BSA, and skim milk was diluted to one-third.