Mentha piperita menthol from

Peppermint oil is the volatile oil extracted from the fresh leaves of the flowering plant of Mentha piperita via steam distillation. Peppermint oil contains not less than 44% menthol. American peppermint oil contains from 50 to 78% of free /-menthol (Fig. 13.12.1) and from 5 to 20% combined in various es-... 

Natural peppermint contains several components that, if ingested, lead to a cold sensation in the mouth. The best known and best understood is (-)-menthol (IV), which is the dominant component of the peppermint oil extracted from Mentha piperita and M. arvensia. 

Menthol is the isomer that occurs most widely in nature. It is the main component of peppermint and cornmint oils obtained from the Mentha piperita and Mentha arvensis species. Esterified menthol also occurs in these oils (e.g., as the acetate and iso valerate). Other menthol stereoisomers may be present in these oils as well. 

Menthanes, which include menthol, menthonc, terpineol, and carvone, are some of the best known monoterpene-based chiral synthons in organic synthesis. They are all relatively inexpensive and are commercially available in bulk quantities. Menthols and their corresponding ketones, menthones. were first isolated from peppermint oils of various species of Mentha piperita L [30]. Menthones can exist in two diastereomeric forms, each with two enantiomers. The ones with the methyl and isopropyl groups in a Zrans-orientation are termed menthones, whereas those with the two in a cz.s-orientation are isomenthones. /-Menthone (22), also denoted as (7A,4S)-(-)-menthone. is the most abundant stereoisomer and is obtained by the dry distillation of the wood of Finns palustris Me II [31]. It can also be produced chemically by chromic acid oxidation of /-menthol (23) [32]. /-Menthone is commercially available in bulk quantities with optical purities of 90-98% ee [33]. 

Oil of Peppermint. Col perm in Mintec. Steam-distilled, volatile oil from fresh flowering plant Mentha piperita L, Labiatae. The Japanese oil, also known as oil of Poho, is the liq portion remaining after the separation of menthol from the oil of Mentha arvensts L., Labiatae. Constit Not less than 50% total menthol including 5 -9% esters ealed as menthyl acetate menthyl isovalerate, menthone, inactive pinene, /-limonene, cadinene, phellandrene, some acetaldehyde, isovaleric aldehyde, amyl alcohol, dimethyl sulfide. 

Menthan-3-ol forms four pairs of enantiomers. The levorotatory (1J ,3R,45)-enantiomer referred to as (-)-menthol represents the most significant. It is the major component of peppermint oil obtained from the fresh-flowering plant Mentha piperita (Labiatae), and is widely used for flavoring and as fragrance in confectionery and perfumery. 

The biosynthetic route to menthol, starts from isopentenyl- and dimethylallyl diphosphate, which in the case of mint derive from the triose-pyruvate pathway, and consists of eight discrete steps (see also section 7.1.2). This route was established by feeding experiments with radio-lahelled intermediates and cell-free enzyme studies. [110] Condensation of isopentenyl- and dimethylallyl diphosphate gives geranyl diphosphate, which is cyclised to (-)-limonene. Both steps are Mg +-dependent. By-products of the cyclisation are around 2 % of myrcene and both, a- and y -pinene. The limonene synthases in Mentha piperita and Mentha spicata are identical, which shows how closely related to each other the species are. 

Definition Volatile oil from steam distillation of Mentha piperita, contg. menthol, and menthyl esters incl. menthyl acetate, and menthone Properties Colorless to pale yel. liq., strong penetrating peppermint odor, pungent taste producing sensation of cold when air is drawn into mouth sol. in 4 vols 90% alcohol very si. sol. in water dens. 0.896-0.908 ref. index 1.460-1.471 (20 C)... 

Juniperus communis samples were investigated by HS-SPME, GC-MS and GC-FID (Filipowicz et al, 2009). SPME-GC-MS was also used to determine monoterpene compounds in Mentha piperita (Rohloff, 1999). Author also compared the results obtained using SPME and steam distillation. Compared to solvent-based samples from essential oil distillation, relatively higher amounts of high-volatile monoterpenes and smaller quantities of less volatile compounds such as menthol and menthone were detected in SPME sampling. 

Evidence for conjugate reduction as a key step in monot-erpene biosynthesis has been obtained from studies of the oxygenated monoterpenes of Mentha piperita (Fig. 19.10) (Croteau, 1984). The pathway from isopiperitenone to the menthol esters was deduced largely by time-course studies and direct feeding experiments. Other evidence supports the intermediacy of /-limonene (11) as the first cyclization product of GPP in this plant. This is followed by the adlylic oxidation of the olefin and subsequent isomerization and reduction of the double bonds of isopiperitenone to the men-thones (such as 26). Furthermore, stereospecific dehydrogenases responsible for the synthesis of /-menthol (27) and d-neomenthol (28) have been isolated (Croteau, 1984). 

Peppermint oil is derived from the dried leaves and flowering tops of Mentha piperita (Lamiaceae). The oil consists of about 50% menthol. The taste and odour of peppermint oil are also influenced by some of its minor components, notably the menthol esters... 

Menthol is a major component of various mint oils. The plant oil, often referred to as peppermint oil (from Mentha piperita) or cornmint oil (from Mentha arvensis), is readily extracted from the plant by steam distillation (Wichtel, 2002). It has a pleasant typical minty odor and taste, and is widely... 

Chang JH, Shin JH, Chung IS, Lee HJ (1998) Improved menthol production from chitosan-elicited suspension culture of Mentha piperita. Biotechnol Lett 20 1097-1099... 

Worldwide, 12 000 tonnes of (—)-menthol are produced per year (1998). The majority is natural menthol from Mentha arvensis or Mentha piperita and only a quarter is produced synthetically. Nevertheless, the synthetic route is important as the price from natural resources fluctuates if the availability is limited due to bad... 

In other systems, a particular structure may be found as a mixture of diastereoisomers. Peppermint (Mentha x piperita Labiatae/Lamiaceae) typically produces (—)-menthol, with smaller amounts of the stereoisomers (+)-neomenthol, (+)-isomenthol, and (+)-neoisomenthol, covering four of the possible eight stereoisomers (Figure 5.16). Oils from various Mentha species also contain significant amounts of ketones, e.g. (—)-menthone, (+)-isomenthone, (—)-piperitone, or (+)-pulegone. The metabolic relationship of... 

Another favorite substance for medicine and cosmetics is menthol. It is obtained from a number of heibs, peppermint (Mentha x piperita L.) being the most common source (Fig. 2.13). The peppermint plant contains about 1-3 % essential oil, which can be obtained by a chemical separation method called steam distilla-tiom About half of the oil is menthol and its derivatives, terpenes, and flavonoids. Menthol has a pleasant odor and eooling effect, and these two properties are why... 

Presumably the most studied essential oil plant is peppermint (Mentha x piperita L.). Already in the 1950s Lemli (1955) stated that the proportion of menthol to menthone in peppermint leaves changes in the course of the development toward higher menthol contents. Lawrence (2007) has just recently shown that from immature plants via mature to senescent plants the content of menthol increases (34.8-39.9 8.2%) and correspondingly the menthone content decreases dramatically (26.8-17.4-4.7%). At the same time, also an increase of menthyl acetate from 8.5% to 23.3% of the oil could be observed. At full flowering, the peppermint herb oil contains only 36.8% menthol but 21.8% menthone, 7.7% menthofuran, and almost 3% pulegone due to the fact that the flower oils are richer in... 

The most important monoterpene alcohols are menthol, cis- and trans-piperitol, cis- and trans-pulegol, isopulegol, cis- and trans-caiveol, thymol, carvacrol, terpinen-4-ol, and a-terpineol. The latter two bear a tertiary alcohol function. Terpinen-4-ol is a major antibacterial component of tea tree oil Melaleuca alternifolia). a-Terpineol is a major compound in cardamom oil. (—)-Menthol is a main constituent in mint oils Mentha x piperita and other Mentha species). Terpinen-4-ol is typically found in marjoram oils Origanum majorana) a-terpineol occurs in various essential oils including those from Melaleuca viridiflora and nutmeg Myristica fragrans). Thymol and carvacrol are... 

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