3-гидрокси-2-метил-4-пирона

Описание

Maltol has a warm, sweet, fruity odor and a jam-like odor in solution. It may be prepared by alkaline hydrolysis of streptomycin salts; also from piperidine to pyromeconic acid and subsequent methylation at the 2 position.

Химические свойства

White, crystalline powder; characteristic caramel-butterscotch odor and suggestive of a fruity-strawberry aroma in dilute solution. Melting range 160–164C. Slightly soluble in water; more soluble in alcohol and propylene glycol.

Вхождение

Reported found in the bark of young larch trees (Pinus larix), pine needles (Abies alba), chicory, wood tars and oils, and roasted malt. Also reported found in wheat and rye bread, milk, butter, smoked pork, beer, cocoa, coffee, roasted barley, filberts, peanuts, soybean, beans, tamarind, licorice, sake, malt, dried bonito, clam and cocoa liquor.

Использование

A fragrance molecule used in flavor enhancers and fragrances.

Методы производства

Maltol is mainly isolated from naturally occurring sources such as beechwood and other wood tars; pine needles; chicory; and the bark of young larch trees. It may also be synthesized by the alkaline hydrolysis of streptomycin salts or by a number of other synthetic methods.

Подготовка

Maltol may be produced synthetically starting from kojic acid . Alternatively, it can be isolated from beechwood tar or from extracts of needles from the genus Abies. Commercially available extracts fromAbies balsamea needles, which are also used as flavor and fragrance materials, usually contain 3–8% maltol. It is used in aroma compositions with a caramel note and as a taste intensifier in, for example, fruit flavors (particularly in strawberry flavor compositions).

Определение

ChEBI: A natural product found in Cordyceps sinensis.

Общее описание

White crystalline powder with a fragrant caramel-butterscotch odor. pH (5% aqueous solution) 5.3.

Реакции воздуха и воды

May be sensitive to prolonged exposure to light and air. Somewhat soluble in water at room temperature. Freely soluble in hot water [Merck]. Slightly soluble in cold water.

Профиль реактивности

3-Hydroxy-2-methyl-4H-pyran-4-one is weakly acidic. Reacts with bases. May react with reducing agents. Volatile with steam.

Пожароопасность

Flash point data on 3-Hydroxy-2-methyl-4H-pyran-4-one are not available; however, 3-Hydroxy-2-methyl-4H-pyran-4-one is probably combustible.

Фармацевтические приложения

Maltol is used in pharmaceutical formulations and food products as a flavoring agent or flavor enhancer. In foods, it is used at concentrations up to 30 ppm, particularly with fruit flavorings, although it is also used to impart a freshly baked odor and flavor to bread and cakes. When used at concentrations of 5–75 ppm, maltol potentiates the sweetness of a food product, permitting a reduction in sugar content of up to 15% while maintaining the same level of sweetness. Maltol is also used at low levels in perfumery.

Фармаколо?гия

In mice, spontaneous motor activity was depressed by sc injection oi relatively low doses of maltol (75 mg/kg), hexobarbitone sleeping time was prolonged by sc or oral administration of 300 mg/kg, and convulsions induced by pentylenetetrazole or strychnine were inhibited by sc injection of toxic doses (500 mg/kg), but 1 mM concentrations of maltol had no effect on oxygen uptake by slices of the brain cortex of the rat (Aoyagi et al. 1974).

Профиль безопасности

Moderately toxic by ingestion, intraperitoneal, and subcutaneous routes. A skin irritant. Human mutation data reported. When heated to decomposition it emits acrid smoke and irritating fumes.

Безопасность

Maltol is generally regarded as an essentially nontoxic and nonirritant material. In animal feeding studies, it has been shown to be well tolerated with no adverse toxic, reproductive, or embryogenic effects observed in rats and dogs fed daily intakes of up to 200mg/kg body-weight of maltol, for 2 years.The WHO has set an acceptable daily intake for maltol at up to 1mg/kg body-weight.A case of allergic contact dermatitis, attributed to the use of maltol in a lip ointment, has been reported.
LD₅₀ (chicken, oral): 3.72 g/kg
LD₅₀ (guinea pig, oral): 1.41 g/kg
LD₅₀ (mouse, oral): 0.85 g/kg
LD₅₀ (mouse, SC): 0.82 g/kg
LD₅₀ (rabbit, oral): 1.62 g/kg
LD₅₀ (rat, oral): 1.41 g/kg

Метаболизм

Maltol is rapidly and extensively metabolized in the dog and excreted by the conjugation pathway common to phenolic compounds. Rennhard (1971) reported that 57% of an iv dose was recovered in 24 hr, 88% of the total excretion occurring in the first 6 hr and 65-70% of the dose administered being recovered as sulphate and glucuronide conjugates

хранилище

Maltol solutions may be stored in glass or plastic containers. The bulk material should be stored in a well-closed container, protected from light, in a cool, dry place.

Методы очистки

It crystallises from CHCl3, toluene, aqueous 50% EtOH or H2O, and is volatile in steam. It can be readily sublimed in a vacuum. It forms a Cu2+ complex. [Beilstein 17 III/IV 5916, 18/1 V 114.]

Несовместимости

Concentrated solutions in metal containers, including some grades of stainless steel, may discolor on storage.

Регуляторный статус

GRAS listed. Included in the FDA Inactive Ingredients Database (oral solutions and syrups). Included in the Canadian List of Acceptable Non-medicinal Ingredients.