Graduate School of Frontier Biosciences, Osaka University

Japanese

2,4,6-Trichloroanisole is a potent suppressor of olfactory signal transduction

Journal PNAS (2013) Published online before print September 16, 2013
See also Article Highlights
Authors Hiroko Takeuchi (1), Hiroyuki Kato (2), Takashi Kurahashi (1)

  1. Graduate school of Frontier Biosciences, Osaka University
  2. Daiwa Can Company

Title 2,4,6-Trichloroanisole is a potent suppressor of olfactory signal transduction
PubMed 24043819
Laboratory Physiological Laboratory 〈Prof. Kurahashi〉
Abstract We investigated the sensitivity of single olfactory receptor cells to 2,4,6-trichloroanisole (TCA), a compound known for causing cork taint in wines. Such off-flavors have been thought to originate from unpleasant odor qualities evoked by contaminants. However, we here show that TCA attenuates olfactory transduction by suppressing cyclic nucleotide-gated channels, without evoking odorant responses. Surprisingly, suppression was observed even at extremely low (i.e., attomolar) TCA concentrations. The high sensitivity to TCA was associated with temporal integration of the suppression effect. We confirmed that potent suppression by TCA and similar compounds was correlated with their lipophilicity, as quantified by the partition coefficient at octanol/water boundary (pH 7.4), suggesting that channel suppression is mediated by a partitioning of TCA into the lipid bilayer of plasma membranes. The rank order of suppression matched human recognition of off-flavors: TCA equivalent to 2,4,6-tribromoanisole, which is much greater than 2,4,6-trichlorophenol. Furthermore, TCA was detected in a wide variety of foods and beverages surveyed for odor losses. Our findings demonstrate a potential molecular mechanism for the reduction of flavor.