Characterization of Key Odorants in Meehan’s Mint, Meehania cordata

Abstract

Thirty-five odorants from Meehan's mint, Meehania cordata, were identified using solvent-assisted flavor evaporation (SAFE) and aroma extract dilution analysis (AEDA). Twelve compounds with flavor dilution factors ≥16 were quantitated using stable isotope dilution assays (SIDA). Odor activity values (OAVs) and sensory experiments revealed (−)-(E)-pinocarvyl acetate as a key impact odorant contributing to the plant's unique woody and minty odor. Odor simulation experiments revealed a mixture of 10 compounds, including (2E,6Z)-nona-2,6-dienal (OAV 48000), β-ionone (OAV 33000), (E)-pinocarvyl acetate (OAV 8600), 1-octen-3-one (OAV 2800), and linalool (OAV 990), successfully mimicked the plant odor when combined in their natural concentrations. Three stereoisomers of pinocarvyl acetate were identified including (−)-(E)-, (+)-(E)-, and (−)-(Z)-isomers. The (E) to (Z)-ratio was determined as 95.5% (E) and 0.5% (Z). The enantiomeric ratio of (−)-(E)-to (+)-(E)-was determined as 96% (−)-(E)-and 4% (+)-(E)-pinocarvyl acetate. This study established the basis for future investigations aimed at determining the odorant variability of individual genotypes from natural populations of M. cordata and other members of the Meehenia genus.

Characterization of Key Odorants in Cumberland Rosemary, Conradina verticillata

“…The odorants with the highest OAVs were 1-octen-3-one ( 8 , OAV 2900000) and 1,8-cineole ( 6 , OAV 510000), with earthy-mushroom, and eucalyptus characteristics. Compound 8 has been identified at relatively low levels in some genera of the Lamiaceae family including Mentha, Pycnanthemum, Salvia, and Meehania. − ,, For example, in Meehanina cordata, its concentration was notably lower (45.5 μg/kg) than in C. verticillata (46600 μg/kg) .…”

“…7−9,14,15 For example, in Meehanina cordata, its concentration was notably lower (45.5 μg/kg) than in C. verticillata (46600 μg/ kg). 8 Other odorants with OAVs ≥1 included borneol (22, OAV 10000), bornyl acetate (14, OAV 3700), eugenol (30, OAV 2200), menthone (10, OAV 130), and camphor (11,OAV 72). The results of the OAV calculations showed that all seven odorants had an OAV ≥1, suggesting that all of the quantitated odorants may contribute to the odor of C. verticillata.…”

“…Quantitative olfactory-profile analysis revealed that an odor simulation model prepared by combining the odorants with OAVs ≥1 in a microcrystalline cellulose matrix was a close match to the aroma of C. verticillata. Through omission experiments, it was determined that 1-octen-3-one (6), 1,8cineole (8), and eugenol (30) were key odorants and play essential roles in the aroma character of C. verticillata. The chirality of select odorants was evaluated and 1-octen-3-ol (9, >99%…”

Key Odorants from Daldinia childiae

“…The odour thresholds for odorants including 3 , 8 , 10 , 12 , 18 , 19 , 20 , 23 and 27 were obtained from literature 6,28,29 . The odour thresholds of 16 and 28 were evaluated in pure water at the University of Tennessee, Knoxville according to standards of the American Society of Testing and Materials (ASTM).…”

Mechanistic Similarities of Sesquiterpene Cyclases PenA, Omp6/7, and BcBOT2 Are Unraveled by an Unnatural “FPP-Ether” Derivative

“…The keto group can be reduced with NaBH 4 in MeOH to give alcohol 29 as a single diastereomer, as judged by GC-MS. The conformational flexibility of the cycloheptane ring made it difficult to unambiguously determine the configuration of the newly formed stereogenic center . In addition, a Riley oxidation in CH 2 Cl 2 gave exclusively allyl alcohol 30 , which remarkably gave the more highly substituted allyl alcohol.…”