Mentha menthol

Artificial materials include aUphatic, aromatic, and terpene compounds that are made synthetically as opposed to those isolated from natural sources. As an example, ben2aldehyde may be made synthetically or obtained from oil of bitter almond (51) and t-menthol may be made synthetically or isolated from oil of Mentha arvensis var. to give Bra2iUan mint oil or com mint oil. 

Menthol Manufacture. Of the menthol isomers, only (-)-menthol [2216-51 -5] and (+)-menthol [15356-70-4] are of commercial importance. The most important natural sources of (—)-menthol are the oUs of Mentha arvensis (75—90%) and Mentha piperita (50—65%). The main suppUers ate Japan, China, BrazU, and Taiwan for the former and the United States, CIS, Bulgaria, and Italy for the latter. (—)-Menthol is known for its refreshing, diffusive odor characteristic of peppermint. It also is known for its strong physiological cooling effect, which is useful in cigarettes, dentifrices, cosmetics, and pharmaceuticals. 

Natural menthol is obtained by freezing the essential oU, eg, Mentha arvensis and the menthol crystals ate separated by centrifuging the supernatant hquid away from the crystals. The supernatant oU is then caUed dementholized cornmint oU. Impurities in the crystals come from the essential oU and usuaUy give a slight peppermint aroma to the crystallized menthol. The cornmint oU, rich in (—)-menthone (- 28%) and (—)-menthol (- 32%), can be further processed to give additional natural menthol. 

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. 

Menthol from Cornmint Oil. Mentha arvensis oils, which may contain 70-80% free (—)-menthol, are cooled and the crystals separated by centrifugation. Since the crystalline product contains traces of cornmint oil, this menthol has a slightly herbaceous-minty note. Pure (—)-menthol is obtained by recrystallization from solvents with low boiling points. 

Cornmint oil, Japanese mint oil is produced by steam distillation of the flowering herb Mentha arvensis var. piperascens Malinv. The crude oil contains ca. 70% (-)-menthol, which can be isolated by crystallization at low temperature. 

Japanese mint Mentha canadensis L. (-)-Menthol (about 70)... 

Most menthol is isolated from peppermint oils, especially from crude oil from Mentha arvensis from India. But menthol can also be prepared by chemical synthesis. There are two important commercial processes for the synthesis of menthol. One is based on a renewable resource, /1-pinene from turpentine, and the other on m-cresol from petrochemical origin (Scheme 13.3). 

Natural aroma chemicals Isolation and purification via physical processes Citral from lemon grass oil, eugenol from cloves, menthol from Mentha species... 

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

Peppermint leaf Mentha piperita (Lamiaceae) Menthol, menthone... 

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. Mentha pulegium L. Pulegone, isopulegone, menthol, terpenoids." Digestive tonic, relieve flatulence and colic. 

Mentha spicata L. M. x piperita L. Menthol, menthone, isomenthone, pinene, myrcene, limonene, cineole, cymene, terpinene, carvone, luteolin."-100-107-130 Carminative, stomachic, mild antispasmodic, expectorant, antiseptic, and local anesthetic properties. 

Oil of turpentine, nil free from menthol, tils nl other species of mentha... 

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... 

A silica gel plate, with chlorobenzene as the developing solvent, was used by Bary et al to optimize the separation of citral, citronellol, eugenol, cinnamon, menthol, and mentha by the OPLC technique [22], Detection is obtained by spraying with vanillin-sulfuric reagent, and is carried out using densitometry at 600 nm. 

A number of articles have been written which concern the poor solubilities of products. Suspension cultures of Mentha produce menthol which has very low solubility in water due to its hydrophobicity, and this is considered to be a factor responsible for its low production in the suspension cultures. Cyclo dextrin has a hydrophobic cavity inside the molecule in which menthol can be captured and allow to form a stable complex. A suspension culture of Mentha piperita showed a 70% production enhancement in a medium contain-... 

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