Laska Matthias
Institut für Medizinische Psychologie, Ludwig-Maximilians-Universität München, Goethestr. 31, D-80336 München, Germany.
Chem Senses. 2004 Feb;29(2):143-52. doi: 10.1093/chemse/bjh019.
The ability of 20 human subjects to distinguish between nine enantiomeric odor pairs sharing an isopropenyl group at the chiral center was tested in a forced-choice triangular test procedure. I found (i). that as a group, the subjects were only able to significantly discriminate the optical isomers of limonene, carvone, dihydrocarvone, dihydrocarveol and dihydrocarvyl acetate, whereas they failed to distinguish between the (+)- and (-)-forms of perillaalcohol, perillaaldehyde, isopulegol and limonene oxide; (ii). marked interindividual differences in discrimination performance, ranging from subjects who were able to significantly discriminate between eight of the nine odor pairs to subjects who failed to do so with six of the nine tasks; and (iii). that with none of the nine odor pairs the antipodes were reported to differ significantly in subjective intensity when presented at equal concentrations. Additional tests of the chemesthetic potency and threshold measurements of the optical isomers of dihydrocarvone, dihydrocarveol, and dihydrocarvyl acetate suggest that the discriminability of these three enantiomeric odor pairs is indeed due to differences in odor quality. Analysis of structure-activity relationships suggest that the combined presence of (i). an isopropenyl group at the chiral center; (ii). a methyl group at the para-position; and/or (iii). an oxygen-containing group at the meta-position allows for the discrimination of enantiomeric odor pairs.
在强制选择三角测试程序中，对20名人类受试者区分在手性中心共享异丙烯基的九对对映体气味对的能力进行了测试。我发现：（i）作为一个群体，受试者仅能够显著区分柠檬烯、香芹酮、二氢香芹酮、二氢香芹醇和二氢香芹基乙酸酯的旋光异构体，而他们无法区分紫苏醇、紫苏醛、异蒲勒醇和氧化柠檬烯的（+）-和（-）-形式；（ii）辨别能力存在显著的个体差异，从能够显著区分九对气味对中的八对的受试者到在九项任务中的六项中无法做到这一点的受试者；以及（iii）当以相等浓度呈现时，九对气味对中的任何一对对映体在主观强度上均未被报告有显著差异。对二氢香芹酮、二氢香芹醇和二氢香芹基乙酸酯的旋光异构体的化学感觉效力和阈值测量的额外测试表明，这三对对映体气味对的可辨别性确实是由于气味质量的差异。结构-活性关系分析表明，（i）在手性中心存在异丙烯基；（ii）在对位存在甲基；和/或（iii）在间位存在含氧基团的共同存在允许对对映体气味对进行区分。
