Modeling Odorant–Receptor Contacts: Interactions of Carvone With Ethanol and Phenol as Amino Acid Side‐Chain Mimics

Non‐covalent interactions play a fundamental role in molecular recognition and receptor‐ligand binding, being vital in biological and chemical processes like olfaction. Here we use broadband rotational spectroscopy to investigate the gas‐phase complexes of the odorant carvone with ethanol and phenol, mimicking interactions with serine and tyrosine amino acid side chains. Eight carvone‐ethanol and two carvone‐phenol isomers were identified, each characterized by OH⋅⋅⋅O hydrogen bonds binding to the lone pair of carvone in trans with respect to the methyl group of the carvone ring. Secondary interactions, including CH⋅⋅⋅O and CH⋅⋅⋅π, further modulate the structural preferences of the complexes. A shift to higher‐energy conformers of carvone and ethanol is observed. Our results characterize binding motifs and participating non‐covalent interactions, which may serve as a proxy for exploring general principles relevant to odorant–receptor recognition.