| Abstract: | Mentha haplocalyx Briq. is a plant which belongs to the Mentha genus of the Labiatae family. Yellowish-green oil is obtained from the leaves and stems with 0.05% yield by steam-distillation. Then the oil is fractionated and the isolated compound is purified by recrystallization. White prism crystal is obtained. It is identified as d-8-acetoxycarvotanacetone by UV, IR, NMR and MS. The mixed melting point of synthetic and natural samples has no depression. Their physical constants and spectral behavior also agree with each other. Thus, the structure of the crystalline compound isolated from the oil of Men, ha haplocalyx Briq. is confirmed to be d-8-acetoxycarvotanacetone. The compound has good repellent effect to mosquitoes, gnats and gadflies. |
