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Olfactory sensitivity and odor structure-activity relationships for aliphatic carboxylic acids in CD-1 mice.

Can Güven S, Laska M - PLoS ONE (2012)

Bottom Line: A significant positive correlation between olfactory detection thresholds and carbon chain length of the carboxylic acids with their branching next to the functional carboxyl group was found.In contrast, no such correlation was found for carboxylic acids with their branching at the distal end of the carbon chain relative to the functional carboxyl group.Finally, a significant correlation was found between olfactory detection thresholds and the position of the branching of the carboxylic acids.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden.

ABSTRACT
Using a conditioning paradigm, the olfactory sensitivity of CD-1 mice for a homologous series of aliphatic n-carboxylic acids (ethanoic acid to n-octanoic acid) and several of their isomeric forms was investigated. With all 14 odorants, the animals significantly discriminated concentrations as low as 0.03 ppm (parts per million) from the solvent, and with four odorants the best-scoring animals even detected concentrations as low as 3 ppt (parts per trillion). Analysis of odor structure-activity relationships showed that the correlation between olfactory detection thresholds of the mice for the unbranched carboxylic acids and carbon chain length can best be described as a U-shaped function with the lowest threshold values at n-butanoic acid. A significant positive correlation between olfactory detection thresholds and carbon chain length of the carboxylic acids with their branching next to the functional carboxyl group was found. In contrast, no such correlation was found for carboxylic acids with their branching at the distal end of the carbon chain relative to the functional carboxyl group. Finally, a significant correlation was found between olfactory detection thresholds and the position of the branching of the carboxylic acids. Across-species comparisons suggest that mice are more sensitive for short-chained (C(2) to C(4)) aliphatic n-carboxylic acids than other mammalian species, but not for longer-chained ones (C(5) to C(8)). Further comparisons suggest that odor structure-activity relationships are both substance class- and species-specific.

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Olfactory detection thresholds of CD-1 mice for the four aliphatic carboxylic acids with the branching of the carbon chain next to the functional carboxyl group.Each symbol represents the threshold value of an individual animal. The solid line indicates the regression with the best goodness-of-fit according to linear regression analysis (R2 = 0.66, p<0.001, equation for line of best fit: y = 0.63x−6.90).
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pone-0034301-g004: Olfactory detection thresholds of CD-1 mice for the four aliphatic carboxylic acids with the branching of the carbon chain next to the functional carboxyl group.Each symbol represents the threshold value of an individual animal. The solid line indicates the regression with the best goodness-of-fit according to linear regression analysis (R2 = 0.66, p<0.001, equation for line of best fit: y = 0.63x−6.90).

Mentions: Figure 4 shows the olfactory detection threshold values of the mice for the four aliphatic carboxylic acids with the branching of the carbon chain next to the functional carboxyl group. Thresholds increased from 2-methylpropanoic acid to 2-methylhexanoic acid. Accordingly, linear regression analysis found a significant positive slope for olfactory detection thresholds and carbon chain lengths C4 to C7 of the carboxylic acids with their branching next to the functional carboxyl group (R2 = 0.66, p<0.001, equation for line of best fit: y = 0.63x−6.90).


Olfactory sensitivity and odor structure-activity relationships for aliphatic carboxylic acids in CD-1 mice.

Can Güven S, Laska M - PLoS ONE (2012)

Olfactory detection thresholds of CD-1 mice for the four aliphatic carboxylic acids with the branching of the carbon chain next to the functional carboxyl group.Each symbol represents the threshold value of an individual animal. The solid line indicates the regression with the best goodness-of-fit according to linear regression analysis (R2 = 0.66, p<0.001, equation for line of best fit: y = 0.63x−6.90).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3316622&req=5

pone-0034301-g004: Olfactory detection thresholds of CD-1 mice for the four aliphatic carboxylic acids with the branching of the carbon chain next to the functional carboxyl group.Each symbol represents the threshold value of an individual animal. The solid line indicates the regression with the best goodness-of-fit according to linear regression analysis (R2 = 0.66, p<0.001, equation for line of best fit: y = 0.63x−6.90).
Mentions: Figure 4 shows the olfactory detection threshold values of the mice for the four aliphatic carboxylic acids with the branching of the carbon chain next to the functional carboxyl group. Thresholds increased from 2-methylpropanoic acid to 2-methylhexanoic acid. Accordingly, linear regression analysis found a significant positive slope for olfactory detection thresholds and carbon chain lengths C4 to C7 of the carboxylic acids with their branching next to the functional carboxyl group (R2 = 0.66, p<0.001, equation for line of best fit: y = 0.63x−6.90).

Bottom Line: A significant positive correlation between olfactory detection thresholds and carbon chain length of the carboxylic acids with their branching next to the functional carboxyl group was found.In contrast, no such correlation was found for carboxylic acids with their branching at the distal end of the carbon chain relative to the functional carboxyl group.Finally, a significant correlation was found between olfactory detection thresholds and the position of the branching of the carboxylic acids.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden.

ABSTRACT
Using a conditioning paradigm, the olfactory sensitivity of CD-1 mice for a homologous series of aliphatic n-carboxylic acids (ethanoic acid to n-octanoic acid) and several of their isomeric forms was investigated. With all 14 odorants, the animals significantly discriminated concentrations as low as 0.03 ppm (parts per million) from the solvent, and with four odorants the best-scoring animals even detected concentrations as low as 3 ppt (parts per trillion). Analysis of odor structure-activity relationships showed that the correlation between olfactory detection thresholds of the mice for the unbranched carboxylic acids and carbon chain length can best be described as a U-shaped function with the lowest threshold values at n-butanoic acid. A significant positive correlation between olfactory detection thresholds and carbon chain length of the carboxylic acids with their branching next to the functional carboxyl group was found. In contrast, no such correlation was found for carboxylic acids with their branching at the distal end of the carbon chain relative to the functional carboxyl group. Finally, a significant correlation was found between olfactory detection thresholds and the position of the branching of the carboxylic acids. Across-species comparisons suggest that mice are more sensitive for short-chained (C(2) to C(4)) aliphatic n-carboxylic acids than other mammalian species, but not for longer-chained ones (C(5) to C(8)). Further comparisons suggest that odor structure-activity relationships are both substance class- and species-specific.

Show MeSH
Related in: MedlinePlus