- Structure-Odor Activity Studies on Monoterpenoid Mercaptans Synthesized by Changing the Structural Motifs of the Key Food Odorant 1-p-Menthene-8-thiol
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1-p-Menthene-8-thiol (1) has been discovered as the key odorant in grapefruit juice several decades ago and contributes to the overall odor of the fruit with an extremely low odor threshold of 0.000034 ng/L in air. This value is among the lowest odor thresholds ever reported for a food odorant. To check whether modifications in the structure of 1 would lead to changes in odor threshold and odor quality, 34 mercapto-containing p-menthane and 1-p-menthene derivatives as well as several aromatic and open-chain mercapto monoterpenoids were synthesized. Eighteen of them are reported for the first time in the literature, and their odor thresholds and odor qualities as well as analytical data are supplied. A comparison of the sensory data with those of 1 showed that hydrogenation of the double bond led to a clear increase in the odor threshold. Furthermore, moving the mercapto group into the ring always resulted in higher odor thresholds compared to thiols with a mercapto group in the side chains. Although all tertiary thiols always exhibited low odor thresholds, none of the 31 compounds reached the extremely low threshold of 1. Also, none of the synthesized mercapto monoterpenoids showed a similar odor quality resembling grapefruit. Although the saturated and aromatic analogues exhibited similar scents as 1, the aromas of the majority of the other compounds were described as sulfury, rubber-like, burned, soapy, or even mushroom-like. NMR and MS data as well as retention indices of the 23 newly reported sulfur-containing compounds might aid in future research to identify terpene-derived mercaptans possibly present in trace levels in foods.
- Schoenauer, Sebastian,Schieberle, Peter
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p. 3849 - 3861
(2016/06/01)
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- Steric considerations on improving the diastereomeric ratio of (+)- and (-)-neomenthyl phenyl sulfoxides using bulky-headed oxidant hexadecyltrimethylammonium periodate and assignment of their configuration
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Abstract The bulky-headed oxidant hexadecyltrimethylammonium periodate affords the diastereomeric pairs, (Ss)-(+)/(Rs)-(+) and (Ss)-(-)/(Rs)-(-)-neomenthyl phenyl sulfoxides in stereochemically pure states with improved diastereomeric excess (48% diastere
- Chaudhari, Umesh V.,Singh, Deepak,Deota, Pradeep T.,Bedekar, Ashutosh V.
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p. 370 - 374
(2015/06/02)
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- Synthesis and sensory studies of umami-active scaffolds
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The class of 2-isopropyl-5-methylbicyclo[4.1.0]heptane-7-carboxamides, 1-4, has been identified as potent umami-tasting molecules. A scalable synthesis of this challenging scaffold and new sensory insights will be presented. Interestingly, the umami chara
- Backes, Michael,Paetz, Susanne,V?ssing, Tobias,Ley, Jakob Peter
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p. 1782 - 1797
(2015/02/19)
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- Mild and efficient indium metal catalyzed synthesis of sulfonamides and sulfonic esters
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A facile and efficient method for synthesizing sulfonamides was developed using a catalytic amount of indium metal. A wide range of sulfonamides were synthesized in excellent yields using the new process. The method showed a generality for substrates including less nucleophilic and sterically hindered anilines, and it is also applicable for preparing sulfonic esters from sulfonyl chlorides and alcohols. Georg Thieme Verlag Stuttgart.
- Kim, Joong-Gon,Doo, Ok Jang
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p. 2501 - 2504
(2008/02/13)
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