ISOPULEGOL

Description

Synthesis: Several stereoisomers are possible; only l-isopulegol and d-α-isopulegol have been isolated from mixtures of alcohols obtained by cyclization of d-citronellal.

Description

(–)-Isopulegol is a monoterpene that has been found in the essential oils of several aromatic plants, including Cannabis, with diverse biological activities. It has antibacterial activity against S. aureus, E. faecium, E. coli, and M. smegmatis (MICs = 0.78, 12.5, 0.78, and 1.56 μl/ml, respectively, in an agar diffusion assay) and antifungal activity against C. albicans and A. niger (MIC = 1.56 μl/ml for both in an agar diffusion assay). (–)-Isopulegol inhibits C. albicans morphogenesis, adhesion, and biofilm formation (MICs = 0.125, 4, and 0.25 mg/ml, respectively). In vivo, (–)-isopulegol (50 mg/kg, i.p.) increases immobility time in the forced swim and tail suspension tests and increases the number of head dips in a hole board test and time spent in the open arms of the elevated plus maze in mice, indicating depressant- and anxiolytic-like activity. It reduces the size of ulcerated lesions in the stomach in mouse models of ethanol- and indomethacin-induced gastric lesions when administered at a dose of 100 mg/kg.

Chemical properties

Water-white liquid; mint-like odor. Combustible. Available forms: The acetate.

Chemical properties

Isopulegol is a cyclic nonaromatic alcohol.

Occurrence

l-Isopulegol has been reported found in the essences of lemongrass, East African geranium and Eucalyptus citriodora; d-isopulegol is present in the oils of Backhousia and Baeckea citriodorae; d-neoisopulegol is found in Mentha rotundifolia. Also reported found in mint, mandarin, orange juice, citrus peel oils, currant bud, ginger, corn mint oil, cognac, rum, buchu oil, lemon balm and mastic gum oil

The Uses of ISOPULEGOL

(?)-Isopulegol can be used as a starting material for the enantioselective preparation of:??????

• 8-arylmenthols by Smiles-Truce rearrangement of aryl sulfonates.,·????????
• Stereoisomers of 5,9-dimethylpentadecane.
• Octahydro-2H-chromen-4-ol by Prins cyclization with vanillin in the presence of montmorillonite clay as the catalyst.?????
• p-menthane-3,8,9-triol by catalytic Sharpless dihydroxylation.

Definition

ChEBI: A natural product found in Citrus hystrix.

Preparation

Several stereoisomers are possible; only l-isopulegol and d-α-isopulegol have been isolated from mixtures of alcohols obtained by cyclization of d-citronellal.

Aroma threshold values

Detection: 1 ppm

Taste threshold values

Taste characteristics at 30 ppm: minty cooling, herbaceous peppermint nuance.

Synthesis Reference(s)

Synthetic Communications, 18, p. 2309, 1988 DOI: 10.1080/00397918808082375

General Description

Isopulegol is monoterpene alcohol, a useful ingredient for the production of fragrances in perfume industries. It is also used as a starting material in the manufacture of menthol by the hydrogenation process. Menthol is an important component in cosmetics, pharmaceuticals, and toothpaste.

Flammability and Explosibility

Non flammable