DL-ментол

Описание

Menthol has a mint-like odor and a fresh, cooling taste. It may be prepared by hydrogenation of thymol.

Химические свойства

colorless to white crystalline solid

Физические свойства

Appearance: colorless or white acicular prismatic crystals or white crystalline powder. Solubility: easily dissolved in ethanol, chloroform, ether, liquid paraffin, or volatile oil and soluble in water. Odor: a cool, refreshing, and pleasant mint aroma, sweet odor, and taste cool early after burning. Boiling point: 212?°C. Melting point: 41–43?°C. Specific optical rotation: ?49 to ?50°.

Вхождение

Reported found in peppermint and other mint oils (e.g., M. arvensis), lemon peel oil, cranberry, pineapple, cab bage, thymus, egg, rum, cocoa, tea, honey, avocado, coriander, mango, rice, litchi, dill herb, calamus, juniper berries, fennel, buchu oil, clam and Roman chamomile oil, Mentha species.

История

In the world of aromatic chemicals, menthol is often described as a unique source of skin and mucous membranes. Menthol is mainly extracted from natural plants. The vast majority of natural menthol in the global market is extracted from numerous Asian mint. In 2006, the world’s natural menthol production is 12,800?tons or more. However, due to various factors, the production of natural menthol is becoming less and less. Since the 1960s, Japan, Germany, and other countries had developed the synthetic menthol products. In 1974 the German company Symrise and Japan Takasago Fluidic Systems company launched chemical synthesis of menthol. At present, attention has been paid to the study of menthol analogy substances and the effect of the changes of molecular structure on the aroma and cool sensation. Some studies have shown that hydroxyl groups located in the branched or 1, 4 chain cannot show a sense of cool. The researchers believed that menthol analogy substances with optical activity should be able to show different, surprising cooling effect, and the structure of hydroxyl alkyl groups is the key point to have a cooling effect. The Japanese chemist Ryoji Noyo and his colleagues found that in BINAP and rhodium complexes as catalysts for asymmetric hydrogenation reaction, the synthesis of menthol is very effective. Because of the contribution of asymmetric organic synthesis, they won the 2001 Nobel Prize in Chemistry.

Использование

DL-Menthol may be used as an extraction solvent for the determination of parabens in food products, cosmetics and pharmaceuticals using liquid-liquid microextraction with high performance liquid chromatography-diode array detection (HPLC-DAD). It may also be used for the preparation of hydrophobic deep eutectic solvent (DES) in the extraction and determination of methylparaben, propylparaben, and butylparaben from cosmetics samples using syringe-to-syringe dispersive magnetic nanofluid microextraction procedure (SS-DMNF-ME) with high-performance liquid chromatography technique (HPLC).

Подготовка

By hydrogenation of thymol.

Показания

For external application, it is applied locally and often used to relieve pain and itching. A nasal drip is used in the head cold. Inhalation or spray is used for sore throat. Oral administration can promote digestion.

Общее описание

White crystalline solid with a peppermint odor and taste.

Реакции воздуха и воды

Insoluble in water.

Профиль реактивности

DL-Menthol is incompatible with butyl chloral hydrate, camphor, phenol, chloral hydrate, Exalgine, betanaphthol, resorcinol or thymol in triturations; potassium permanganate, chromium trioxide and pyrogallol. DL-Menthol is also incompatible with strong oxidizers.

Опасность

Irritant to mucous membranes on inhalation.

Пожароопасность

DL-Menthol is combustible.

Клиническое использование

It can be clinically used to assist anesthesia, postoperative analgesia, intercostal nerve block, trigeminal nerve block, occipital nerve block, and so on. When applied locally, it can promote blood circulation, diminish inflammation, relieve itching, relieve pain, relieve edema, and so on.

Профиль безопасности

Poison by intravenous route. Moderately toxic by ingestion and intraperitoneal routes. A severe eye irritant. Incompatible with phenol, p-naphthol, resorcinol or thymol in trituration, potassium permanganate, chromium trioxide, pyrogallol. Combustible liquid. \When heated to decomposition it emits acrid smoke and irritating fumes.