A patent filed on behalf of Takasago International Corp identifies OR2L3 as a receptor for α-terpineol, 4-terpineol, and 4-methyl acetophenone, with additional responses to indole and skatole. Identified as antagonists are cis-3-hexenyl hexanoate, Timberol, and Santaliff. While the agonists as a group may not seem to show an obvious pattern of an aroma note, the […]
Read MoreVeithen et al (2015), writing about OR1D2’s broadly tuned agonist spectrum, claim that “the different agonists are not linked by a common organoleptic characteristic or note.” Here we present evidence, in the form of a differential experiment, to refute that statement. The following mixtures were prepared: 1.) tetrahydromyrcenol 0.6g, bourgeonal 15% in EtOH 0.9g, floralozone […]
Read MoreAfter finding that OR51E1 agonists have a cheesy note, the author has targeted three more receptors with agonist/antagonist differential experiments. For OR2A25, the aroma of unmixed geranyl acetate was compared with that of the same compound mixed with methyl salicylate. Geranyl acetate is an agonist for OR2A25. Methyl salicylate is an antagonist for this receptor, […]
Read MoreOR51E1 is a receptor for fatty acids with 3-10 carbon atoms, particularly those with cheesy or sweaty perceptual notes. But this receptor is also sensitive to methyl eugenol, methyl salicylate, and menthol, none of which smell cheesy or sweaty. Previously it was hypothesized on the PrimaryOdors website that OR51E1 must encode a milky quality, since […]
Read MoreA dissertation by Kang (2000) details results of OR-ligand assays for indole, Hedione, and naphthalene. The data show each molecule generating responses in a widespread, discontinuous, random-looking array of odorant receptors. Most of these receptors had not previously been deorphaned, and indeed assays typically suffer from some ORs failing to express on the cell surface […]
Read MoreFrançoise et al ([1], [2]) have identified OR2AG1 as a receptor associated with green pea, beany, grassy, galbanum, and bell pepper aroma characters of substituted pyrazines. This class of aroma compounds tends to have nutty, earthy, cacao, roasty, and potato type odors, and the compounds are almost all OR5K1 agonists (Marcinek et al, 2021), although […]
Read MoreWhile it is believed that very few real world odors are “primary”, since neary every aroma compound would have multiple human olfactory receptors that are sensitive to it, empirical measurements of receptors’ responses to odors usually identify at most a handful of receptors, often as few as one or even zero. To compound the problem, […]
Read MoreWhile aromas must certainly occupy a perceptual space, the dimensionality of this space remains mired in uncertainty. It has even been argued that the number of dimensions might equal the total number of olfactory receptors themselves! Conceivably, the perceptual space could be less than 400-dimensional, perhaps as little as 30-40 dimensions, if the various receptors […]
Read MoreThe author is unusually sensitive to myrac aldehyde (also known as Empetal) and perceives in it an intense milky aroma. Other individuals do not seem to share this perception, or at least not to the same degree. Myrac aldehyde is a precursor to the production of lyral, and the two molecules differ very little in […]
Read MoreThere’s a perceptual aroma note, common to such aroma characters as berry, wine, grape, plum, geranium, anise, and clove, that can only be described as “purple”. It appears to make up part of the two candidate primaries referred to on this website as jammy and xyloenanthic. “Purple” smelling aroma molecules are disproportionately associated with the […]
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