Acridinone-Sulfonamide Hybrids: Synthesis, photophysical properties, DFT Analysis, and Antiviral Docking Against Adenovirus

In this investigation, acridinone-based sulfonamides 6a-6j and 10a-10j were synthesized, and their structures were characterized using various spectroscopic techniques. Density Functional Theory ( DFT) calculations indicated that the introduction of electron-withdrawing group(s) stabilizes the molecular orbital energy gap between HOMO-LUMO . Adding an electron-withdrawing group in the para position enhances both the reactivity and molecular softness of the compounds. Molecular electrostatic potential (MEP) mapping revealed that the carbonyl and sulfonyl functional groups serve as primary nucleophilic sites, facilitating interactions with various active biological receptors. Molecular docking studies against the target protein (PDB ID: 9cm2) indicated that compounds 6d , 6h , and 10d possess the highest binding affinities, ranging from − 11.1 to -10.8 kcal/mol, and exhibit the lowest inhibition constants ( Ki ). These compounds were compared with the standard antiviral drug cidofovir, which demonstrates multiple hydrogen bonding, π-π stacking, π-sulfur interactions, and hydrophobic interactions that enhance binding activity. Photophysical studies revealed that the 10a-10j compounds exhibit improved emission properties with high quantum yields. Overall, the 10a - 10j compounds exhibit effective fluorescence, and specific compounds have been identified as potential antiviral leads for further investigation.