Characterization of Odorants in White Leaf Mountain Mint, Pycnanthemum albescens

Abstract

White leaf mountain mint, Pycnanthemum albescens Torrey & A. Gray, also known as white mountain mint or white leaved mountain mint, is a species endemic in the American Southeast. In the present study, 24 odorants were identified using solvent-assisted flavor evaporation, aroma extract dilution analysis, and gas chromatography–mass spectrometry. Nine odorants with flavor dilution factors ≥16 were quantitated by stable isotope dilution assays, and odor activity values (OAVs) were calculated. In addition, the enantiomeric proportions of several chiral odorants were determined by chiral chromatography. Odorants with OAV ≥1 included 1,8-cineole (eucalyptus; OAV 9200), myrcene (terpeny; OAV 1400), linalool (floral, citrus; OAV 370), β-ionone (floral, violet; OAV 64), borneol (earthy; OAV 55), bornyl acetate (earthy, fruity; OAV 19), and eugenol (clove; OAV 3.1). Odor simulation experiments revealed that a mixture of the odorants with OAV ≥1 successfully mimicked the odor of an aqueous extract of the plant when combined in their natural concentrations. This study lays the groundwork for future studies aimed at determining the natural aroma variation within different populations of P. albescens and aids in the future development of selections and hybrids with targeted aroma profiles of commercial interest.

Characterization of Odorants in Loomis’ Mountain Mint, Pycnanthemum loomisii

“…The presence of only a single enantiomer of menthone has been previously reported in other Pycnanthemum species, − and in the closely related genus Mentha , because of (2 S ,5 R )-(−)-menthone being stereospecifically derived from ( S )-(−)-limonene . Similarly, the presence of only the (1 S ,2 R ,4 S )-(−)-bornyl acetate enantiomer is also in agreement with its composition in other Pycnanthemum species. , For α-pinene and borneol, both enantiomers were detected, but a single enantiomer was dominant over the other (Figure ). ( S )-(−)-α-Pinene and (1 S ,2 R ,4 S )-(−)-borneol composed 95% of their respective enantiomeric pairs.…”

“…Similar results were also found for a quantitative olfactory profile analysis of P. albescens, in which the predominant odor attribute was eucalyptus, followed by mint-fresh and mint-medicinal . The intensity of the eucalyptus odor attribute was not as predominant in the odor profile of either P.…”

“…27 Similarly, the presence of only the (1S,2R,4S)-(−)-bornyl acetate enantiomer is also in agreement with its composition in other Pycnanthemum species. 7,11 For αpinene and borneol, both enantiomers were detected, but a single enantiomer was dominant over the other (Figure 5).…”

“…Finally, the odorants with the highest OAVs in P. albescens were determined to be 1,8-cineole (OAV 9200), myrcene (OAV 1400), linalool (OAV 370), and β-ionone (OAV 64) . This study, focused on the odor character of P.…”

“…10 Finally, the odorants with the highest OAVs in P. albescens were determined to be 1,8-cineole (OAV 9200), myrcene (OAV 1400), linalool (OAV 370), and β-ionone (OAV 64). 11 This study, focused on the odor character of P. loomisii, provides the culmination of a systematic characterization of four closely related Pycnanthemum species.…”