Exploring the Molecularity of the Odor and Taste Perceptions of “Brown”: A Computational Approach

We have developed a methodology that seeks to associate the molecularity of compounds with the perceptions of specific odor or taste. This methodology goes beyond gross structural features for a molecule: aromatic or aliphatic rings, lengths of the aliphatic straight chains, or the nature and variation in the functional groups. We target specific atom pairs–bonded or remote–within the smell and taste molecule that have structural-electronic features that are reproducible across molecules that elicit similar smell and taste responses. We represent the “structure” of the atom pair by its interatomic distance. The “electronic” aspects are represented by Nuclear Magnetic Resonance (NMR) chemical shifts that uniquely define the electronic environments of the atoms. We used quantum chemistry calculations and the density functional theory (DFT) to determine the chemical shifts and interatomic distances (through the Z-matrix). We used this methodology to process 19 molecules that elicited the smell of “brown,” and 18 molecules that elicited the taste of “brown.” These molecules were accessed through odor and taste indices from the GoodScentsCompany resource (https://www.thegoodscentscompany.com/). These “brown” odorants and tastants elicited other associated smells and tastes. We identified and illustrated specific bond pairs that elicited different smells and tastes. While smell and taste are intrinsically related, our studies also show atom pairs that are likely responsible exclusively for smell and taste, as well as pairs that elicit both. This work will be impactful in the domain of drug design in the pharmaceutical industry, in addition to enhancing our understanding of how a chemical catalyzes the process that results in chemosensory perception.