Lehrstuhl für Allgemeine Lebensmitteltechnologie , Technische Universität München , Maximus-von-Imhof-Forum 2 , D-85354 Freising-Weihenstephan , Germany.
Frontier Research Center for Advanced Material and Life Science, Faculty of Advanced Life Science , Hokkaido University , Kita 21 Nishi 11 , 001-0021 Sapporo , Japan.
J Agric Food Chem. 2019 Jan 30;67(4):1187-1196. doi: 10.1021/acs.jafc.8b06599. Epub 2019 Jan 14.
The enantiomers of a homologous series (C6-C10) of 2-mercapto-4-alkanones were obtained by lipase-catalyzed kinetic resolution of the corresponding racemic 2-acetylthio-4-alkanones. Their configurations were assigned via vibrational circular dichroism and H NMR anisotropy based methods. Odor thresholds and odor qualities were determined by capillary gas chromatography-olfactometry using chiral stationary phases. There were minima of the odor thresholds for the chain lengths C7 and C8. Except for chain length C8, the enantiomers of the other homologues showed similar odor thresholds. The odor qualities ranged from pungent (C5) to mushroom (C9 and C10) and were similar to those known for the corresponding 1-alken-3-ones with one less C atom. In contrast to their positional isomers (4-mercapto-2-alkanones), the investigated 2-mercapto-4-alkanones do not meet the requirements of a "tropical olfactophore" (i.e., compounds possessing a 1,3-oxygen-sulfur functionality and specific arrangements of the substituents).
通过脂肪酶催化动力学拆分相应的外消旋 2-乙酰硫代-4-烷酮，得到了一系列（C6-C10）2-巯基-4-烷酮的对映异构体。通过振动圆二色性和基于 H NMR 各向异性的方法确定了它们的构型。使用手性固定相通过毛细管气相色谱-嗅觉测定法确定了气味阈值和气味质量。在链长 C7 和 C8 处存在气味阈值的最小值。除了链长 C8 之外，其他同系物的对映异构体表现出相似的气味阈值。气味质量范围从刺鼻（C5）到蘑菇味（C9 和 C10），与相应的少一个碳原子的 1-烯-3-酮的气味质量相似。与它们的位置异构体（4-巯基-2-烷酮）不同，所研究的 2-巯基-4-烷酮不符合“热带嗅子”（即具有 1,3-氧-硫官能团和特定取代基排列的化合物）的要求。
