Unraveling the Interaction of Synthesized Thienoangelicin Derivative by Fluorescence Studies with Solvents, Bovine Serum Albumin and Metal Ions

Abstract

AbstractThe growing importance of angelicin derivatives in medicine has prompted us to develop an efficient synthesis strategy for a thienoangelicin derivative, ethyl 8‐methyl‐2‐oxo‐2H‐thieno[2,3‐h]chromene‐3‐carboxylate (MTCE), and investigate its potential applications in spatial probing, therapeutics, and optical sensing. This novel fluorophore, MTCE, exhibits large Stokes shift due to the intramolecular charge separation between the thiophene and coumarin nucleus in the excited state. This indicates its potential for probing spatial polarity. Specific solute‐solvent interactions play a significant role in experimentally calculated excited state dipole moment, including long‐range electrostatic interactions and hydrogen bonding. The multi‐spectroscopic and molecular docking approaches reveal that novel MTCE also interacts in subdomain IIA of BSA by forming ground state complexes following a static quenching mechanism, with the binding constant calculated at ∼104 M−1. The complexation is spontaneous (ΔG ∼−24 kJ mol−1), and enthalpy‐driven (ΔH∼−43 kJ mol−1 and ΔS∼−61 J mol−1), and is primarily mediated by hydrogen bonding and van der Waal forces. Furthermore, the unique fluorescence selectivity of MTCE towards Fe3+ ions under neutral pH conditions, through the formation of a 1 : 1 stoichiometric complex, sets it apart from other common metal ions. Therefore, MTCE holds promising potential for effective utilization in optical sensing applications targeting metal ions.