Affinities of nutty and green-smelling pyrazines and thiazoles to odorant-binding proteins, in relation with their lipophilicity

Thirty-two green- and/or nutty-smelling compounds, most of them pyrazine and thiazole derivatives, were tested in ligand binding assays with purified 19 kDa bovine and 22 kDa porcine olfactive binding proteins (OBPs). Unlike the nutty ones, all the green odorants were found to be good ligands for both proteins. Lipophilicity appears as an interesting discriminating physicochemical parameter, predictive of the affinity for OBPs and of the related odour profile.