Menthol menthyl acetate

Menthol (hRf 15) and menthyl acetate hRt 55) yielded blue chromatogram zones caryophyllene hRf 90) and caryophyllene epoxide hRf 20 — 25) appeared red-violet and thymol hRf 40 — 45) appeared brick red in color. 

Fig. 1 Schematic sketch (A) of the separation of essential oil components (ca. 500 ng of each component) and reflectance scan of the mixture (B). Menthol (1), caryophyllene epoxide (2), thymol (3), menthyl acetate (4), caryophyllene (5), mixture (G).

Menthol forms an acetate, menthyl acetate,. COCHj, a thick... 

Menthyl Acetate.—This ester, of the formula CHg. CO. OC, H g, is-present in oil of peppermint, its odour being an important characteristic of that oil. It can be prepared by heating menthol with acetic anhydride and sodium acetate. Its characters are as follows —... 

Figure 11.6 indicates approximate /-values for some of the components in peppermint oil on a BPX-5 column this column selects mainly on the basis of molecular weight and shape. For example p-pinene has the same molecular weight as limonene but has a more compact shape and thus a lower /-value. Menthyl acetate has a higher /-value than menthol because of its higher molecular weight. 

Menthol from Dementholized Cornmint Oil. Dementholized cornmint oil, from which (-)-menthol has been removed by crystallization and which still contains 40-50% free menthol, can be reused for producing (-)-menthol. The fairly large quantity of (-)-menthone in the oil (30-50%) is hydrogenated to form a mixture of mainly (-)-menthol and (+)-neomenthol the (-)-menthyl esters present (chiefly (-)-menthyl acetate) are saponified. Additional (—)-menthol is then separated from other components by crystallization, distillation, or via the boric acid esters. 

Menthyl acetate is prepared by acetylation of (-)-menthol (e.g., with acetic anhydride). It is used mainly in peppermint flavors and reconstituted peppermint oils, but also to a small extent in perfumery. 

Occurs in essential oils. It is synthesized by esterification of racemic menthol. Its odor is crisper and less fruity than that of (—)-menthyl acetate. It is used for essential oil compositions and occasionally in household perfumery. 

Mentha piperita and Mentha canadensis Menthyl acetate Menthol [94]... 

Mentha arvensis L. M. haplocalyx Briq. China Menthol, menthone, menthyl acetate.33 Stimulate gastrointestinal tract motility and central nervous system, dilate peripheral blood vessels. Increase sweat gland secretion. 

N.A. Menthol, menthone, menthyl acetate, camphene, limonene, terpenoids." Treat colds, sore throats, sore mouth. 

Menthyl acetate (136) (+)-Menthyl acetate (137) (->Menthol (138) (+>Menthyl acetate (137) Fig. (26). Asymmetric hydrolysis of ( )-menthyl acetate to obtain pure (-)-menthol... 

Peppermint Mentha piperita (-)-Menthol, (-)-menthone (35), (-)-menthyl acetate (36) 95,100... 

SYNS FEMA No. 2668 MENTHOL, ACETATE (SCI) MENTHYL ACETATE MENTHYL ACETATE racemic P-MENTH-3-YL ESTER-dl-ACETIC ACID... 

Citral Geraniol Citronellol Geraniyl acetate Menthol Menthyl esters Menthone (Pinene, Limonene)... 

America, and Japan. The main constituents of the essential oil are a- and p-pinene, limonene, cineol, ethyl amylcarbinol, menthone, menthol, isomenthol, menthyl acetate, and piperitone. It has a strong mint odor with a sweet balsam taste masked by a strong cooling effect. It is widely used in foods, as well as in liquid pharmaceuticals, to 8000 ppm. 

Mentha canadensis, Mentha piperita L-Menthyl acetate L-Menthol Refreshing, cooling, peppermint... 

Composition 30-55% (-)-menthol, 14-32% (-)-menthone, 1.5-10% (-i-)-iso menthone, 2.8-10% menthyl acetate, 3.5-14% 1,8-cineole, 1-9% menthofuran, up to 4% pule-gone [220], as well as 3-octanol, trans-sabinene hydrate, piperitone, viridrflorol, mono- and sesquiterpene hydrocarbons. For further constituents see [221, 222, 223[. On the differentiation between peppermint oils and the detection of dementholised commint oil as a major adulterant see the results of Lawrence et al. [224], The ratio of 1,8-cineole limonene (min. 2) was even implemented in the European Pharmacopoeia. The latter also limits the isopulegol content for Mentha piperita oil to 0.2%. 

The essential oils of the Mentha species are known to be valuable ingredients of pharmaceutical and cosmetic preparations. Menthone, isomenthone, menthol and menthyl acetate, the most important Mentha oil constituents, are defined by their amounts as substantial parameters of mentha oil quality. Even off-line HPTLC/enan-tio-GC coupling has proved to be a valuable method in authenticity control of mint and peppermint oils. After preseparating by HPTLC (silica gel dichloromethane) the menthyl acetate fraction is isolated and directly injected for stereodifferentiation with permethyl p-cyclodextrin. Racemic menthyl acetate was detected by Kreis et al. as a frequently used adulteration of Mentha oils [20]. 

The simultaneous optical resolution of menthone, isomenthone, menthol as well as menthyl acetate has already been achieved using a column combination of three different columns, coated with modified cyclodextrins. All four enantiomeric pairs of these compounds were directly stereoanalyzed. Appropriate dilutions of mint and peppermint oils were analyzed by a single chromatographic run and without any preseparation [93]. 

By means of enantio-MDGC analysis using the column combination SE 52 / DIME-P-CD in PS 268 the simultaneous stereodifferentiation of menthone (1,2) neomenthol (3, 4), isomenthone (5, 6) menthol (7, 8), neoisomenthol (9, 10) and menthyl acetate (11, 12) has been verified and applied to various peppermint oils (Fig. 6.35 Fig. 6.36). 

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