Exploring the odorant and molecular characteristics of molecules sharing the odour notes of an aroma blending mixture

Indexed in OpenAIRE. ; International audience ; The human olfactory system allows to perceive and identify a huge number of odours from few hundreds ORs involved in an olfactory coding whereby one olfactory receptor (OR) recognises multiple odorants while one odorant activates different combinations of ORs. Odours perceived in our environment are mainly the result of mixtures of odorants, but the specific mechanisms involved in their processing remain poorly understood. In previous studies performed at INRAE-CSGA, the perception of a binary mixture of ethyl isobutyrate (Et iB, strawberry-like odour, STR) and ethyl maltol (Et-M, caramel-like odour, CAR) was investigated in comparison with a reference (allyl hexanoate, Al-H, pineapple-like odour, PNA). In humans, the binary specific mixture of Et-iB and Et-M was judged as more typical of a pineapple odour than the individual components, and similar to those of allyl hexanoate. The analysis of the network of odours sharing by 293 molecules described with at least one of the odours STR, CAR or PNA revealed peculiar links between odours, and led to identify 9 STR-CAR and 4 STR-PNA molecules. We investigated the molecular features of these molecules by performing pharmacophore generations using the STR-CAR, STR-PNA sets, both separately and putting together the 13 molecules. Comparing the distances between features of the three models revealed a common distance close to 8 Å between the centres of at least one HY and one HBA. Additionally, the pharmacophore comparison of the three models showed a satisfactory mapping of the features. These results support the hypothesis wherewith molecules sharing the odours involved in a blending mixture could recognise a common set of ORs.