Phenols and lactones in Italo-Mitcham peppermint oilMentha × piperita L.

Abstract

In the acidic fractions of Italo‐Mitcham black peppermint oil (Mentha × piperita L.), some uncommon phenols, carboxylic acids and lactones have been identified, mostly related to menthone. The cis/trans isomers of 2,6‐dimethyl‐heptan‐5‐olide (19 and 20) and the (6R)‐5,6‐dihydro‐3,6‐dimethyl‐benzol[b]furan‐7(4H)‐one (27) are new compounds, their structures have been proved by syntheses; the three diastereoisomers of perhydro‐3,6‐dimethyl‐benzo[b]furan‐2‐one, 16, 17 and 18 as well as 2‐isopropenyl‐5‐methylphenol (1), have not yet been identified in a natural raw material. © 1998 John Wiley & Sons, Ltd.

(R)‐Tonkafuranone and related compounds: Improved synthesis, stereochemical purity in nature, and bioactivities of the pure enantiomers

“…Over many years, a considerable plethora of lactone‐based flavour compounds have been isolated from a broad variety of plants. Several of these substances have been shown to be essential flavour constituents of peppermint oil …”

“…The compound was first described as the dehydrogenated autoxidation product of menthofurane by Woodward and Eastman in 1950 . Thus, it is not surprising that 1a was also found in peppermint oil ( Mentha piperita L.), providing a coumaric and coconut flavour and a mint and tenacious smell …”

Lactones 38: Synthesis and odoriferous properties of p‐menthane lactones

“…The best-known mintlactones 1, 2a-5a and 6 were isolated from the essential oils of several Mentha species. [1][2][3][4][5][6][7] In 1997, Iwabuchi reported the isolation of enantiomeric (+)-3hydroxymintlactone (2b), (+)-mintlactone (3b), (À)-isomintlactone (4b) and (À)-2,3-didehydromintlactone (5b) from the oils of woods Bursera graveolens. [8][9][10] The synthesis of all the eight possible diastereoisomers of the completely saturated analogues of (À)-mintlactone (3a) and (+)-isomintlactone (4a) was reported by Gaudin.…”

“…[11,12] This work allowed Näf to show the occurrence of three diastereoisomers, 7a-7c, in Mentha piperita L. essential oil. [6] In general, lactones 1-7 have all been described as sweet, minty and coumarinic with exceptional odour intensities. [5,[11][12][13][14][15][16][17] Of these, the mixture of mintlactones 3a/4a is widely used in commercial flavours, and lactones 7a-7c are useful in both flavours and fragrances due to their exceptional intensity and typical hay character of coumarin.…”

“…[5,[11][12][13][14][15][16][17] Of these, the mixture of mintlactones 3a/4a is widely used in commercial flavours, and lactones 7a-7c are useful in both flavours and fragrances due to their exceptional intensity and typical hay character of coumarin. [6,11,12] In 1975, Southwell, using 1 H NMR, tentatively identified wine lactone 8 in the excreted urine of koala animals fed with Eucalyptus punctata. [18] Since its isolation lactone 8 has been identified as a significant odorant in a variety of natural sources ranging from black pepper to orange juice to various essential oils.…”