Menthofuran
Menthofuran is a monoterpenoid compound with the molecular formula C10H14O and a molecular weight of 150.22 g/mol. It is a naturally occurring substance found in various essential oils, particularly in peppermint, corn mint, spearmint, and pennyroyal oils. Below is a detailed overview of its properties, uses, and biological significance:
Chemical Properties
- Synonyms: 3,6-Dimethyl-4,5,6,7-tetrahydro-1-benzofuran, 3,9-Epoxy-p-mentha-3,8-diene, (R)-(+)-Menthofuran.
- CAS Number: 494-90-6.
- Physical State: Clear, light yellow liquid.
- Odor: Pungent, musty, nutty, earthy, with a coffee-like aroma.
- Melting Point: 86°C.
- Boiling Point: 80-82°C at 13 mm Hg.
- Density: 0.97 g/mL at 25°C.
- Optical Activity: [α]25/D +90° in methanol.
Biological Role and Significance
- Plant Metabolite: Menthofuran is a secondary metabolite produced in plants, particularly in the genus Mentha (mint). It is derived from (+)-pulegone through a cytochrome P450-mediated hydroxylation process.
- Toxicity: It is known to produce hepatotoxic intermediates via oxidation, making it a potentially harmful compound in high concentrations. This toxicity is particularly notable in pennyroyal oil, where menthofuran is believed to contribute to its fatal effects.
- Nematicidal Activity: Menthofuran has been identified as a nematicide, effective against roundworms.
Synthesis and Occurrence
- Natural Source: Found in peppermint oil, corn mint oil, spearmint oil, and other Mentha species.
- Synthesis: It can be synthesized from (+)-pulegone using fuming sulfuric acid in acetic anhydride, followed by pyrolysis of the resulting sultone.
Applications
- Flavor and Fragrance: Used in the flavor and fragrance industry due to its minty, hay-like odor. However, its use is limited due to its potential toxicity.
- Research: Studied for its role in cytochrome P450 enzyme activity and its metabolic pathways in plants and humans.
Safety and Handling
- Stability: Not stable in solution.
- Safety Statements: S24/25 (Avoid contact with skin and eyes).
- Regulatory Status: Subject to restrictions due to its toxic nature and patent-related issues.
For further details, you can refer to the sources cited above or explore the chemical databases and research articles linked in the search results.