| Title: | "Structure-Odor Relationship Study on Geraniol, Nerol, and Their Synthesized Oxygenated Derivatives" |
| Address: | "Department of Chemistry and Pharmacy, Food Chemistry, Emil Fischer Center , Friedrich-Alexander-Universitat Erlangen-Nurnberg , Henkestrasse 9 , 91054 Erlangen , Germany. Department of Sensory Analytics , Fraunhofer Institute for Process Engineering and Packaging (IVV) , Giggenhauser Strasse 35 , 85354 Freising , Germany" |
| ISSN/ISBN: | 1520-5118 (Electronic) 0021-8561 (Linking) |
| Abstract: | "Despite being isomers having the same citrus-like, floral odor, geraniol, 1, and nerol, 3, show different odor thresholds. To date, no systematic studies are at hand elucidating the structural features required for their specific odor properties. Therefore, starting from these two basic structures and their corresponding esters, namely, geranyl acetate, 2, and neryl acetate, 4, a total of 12 oxygenated compounds were synthesized and characterized regarding retention indices (RI), mass spectrometric (MS), and nuclear magnetic resonance (NMR) data. All compounds were individually tested for their odor qualities and odor thresholds in air (OT). Geraniol, the Z-isomer, with an OT of 14 ng/L, was found to be more potent than its E-isomer, nerol, which has an OT of 60 ng/L. However, 8-oxoneryl acetate was the most potent derivative within this study, exhibiting an OT of 8.8 ng/L, whereas 8-oxonerol was the least potent with an OT of 493 ng/L. Interestingly, the 8-oxo derivatives smell musty and fatty, whereas the 8-hydroxy derivatives show odor impressions similar to those of 1 and 3. 8-Carboxygeraniol was found to be odorless, whereas its E-isomer, 8-carboxynerol, showed fatty, waxy, and greasy impressions. Overall, we observed that oxygenation on C-8 affects mainly the odor quality, whereas the E/ Z position of the functional group on C-1 affects the odor potency" |
| Keywords: | Acyclic Monoterpenes Gas Chromatography-Mass Spectrometry Isomerism Magnetic Resonance Spectroscopy Molecular Structure Odorants/*analysis Olfactometry Oxygen/chemistry Terpenes/chemical synthesis/*chemistry 8-hydroxygeraniol gas chromatography-olfactomet; |
| Notes: | "MedlineElsharif, Shaimaa Awadain Buettner, Andrea eng 2016/11/01 J Agric Food Chem. 2018 Mar 14; 66(10):2324-2333. doi: 10.1021/acs.jafc.6b04534. Epub 2016 Nov 7" |
