Insect repellent compound

Abstract

Dihydronepetalactone, a minor natural constituent of the essential oil of catmints ( Nepeta spp.) such as Nepeta cataria , has been identified as an effective insect repellent compound. Synthesis of dihydronepetalactone may be achieved by hydrogenation of nepetalactone, the major constituent of catmint essential oils. This compound, which also has fragrance properties, may be used commercially for its insect repellent properties.

1 . A composition for repelling an insect or tick from a host for the insect or tick, comprising in admixture (a) 1S,9S,5R,6R-5,9-dimethyl-3-oxabicyclo[4.3.0]nonan-2-one, and (b) a carrier to adjust the concentration of the 1S,9S,5R,6R-5,9-dimethyl-3-oxabicyclo[4.3.0]nonan-2-one within the composition.  
   
   
       2 . A composition according to  claim 1  wherein the carrier is a liquid, a solid or a semi-solid.  
   
   
       3 . A composition according to  claim 1  wherein the carrier comprises a polymer.  
   
   
       4 . A composition according to  claim 1  wherein the carrier is selected from one or more members of the group consisting of liquid aliphatic and aromatic hydrocarbons; aliphatic and aromatic compounds having alcohol, ester, aldehyde and ketone functional groups; and finely divided organic and inorganic solid materials.  
   
   
       5 . A composition according to  claim 1  wherein the carrier comprises ethyl alcohol.  
   
   
       6 . A composition according to  claim 1  further comprising one or more cosmetic adjuvants selected from the members of the group consisting of thickeners, buffering agents, chelating agents, preservatives, fragrances, antioxidants, gelling agents, stabilizers, surfactants, emollients, coloring agents, waxes, fungicides, sunscreening agents, sunblocking agents, vitamins, tanning agents, plant extracts, anti-inflammatory agents, anti-oxidants, radical scavenging agents, retinoids, alpha-hydroxy acids, antiseptics, antibiotics, antibacterial agents, antihistamines, soaps, shampoos and deodorants, and mixtures thereof.  
   
   
       7 . A composition according to  claim 1  which comprises 1S,9S,5R,6R-5,9-dimethyl-3-oxabicyclo[4.3.0]nonan-2-one in an amount of from about 0.01% to about 20% weight percent, based on the weight of the whole composition.  
   
   
       8 . A composition according to  claim 1  which is fabricated in the form of a solution, suspension, cream, ointment, gel, spray, lotion, foam, powder or aerosol.  
   
   
       9 . A method of preparing a composition to be applied to the surface of a host for an insect or tick, comprising admixing with 1S,9S,5R,6R-5,9-dimethyl-3-oxabicyclo[4.3.0]nonan-2-one a carrier to adjust the concentration of the 1S,9S,5R,6R-5,9-dimethyl-3-oxabicyclo[4.3.0]nonan-2-one within the composition.  
   
   
       10 . A method according to  claim 9  wherein the carrier comprises a polymer.  
   
   
       11 . A method according to  claim 9  wherein the carrier is selected from one or more members of the group consisting of liquid aliphatic and aromatic hydrocarbons; aliphatic and aromatic compounds having alcohol, ester, aldehyde and ketone functional groups; and finely divided organic and inorganic solid materials.  
   
   
       12 . A method according to  claim 9  wherein the carrier comprises ethyl alcohol.  
   
   
       13 . A method according to  claim 9  further comprising admixing with the composition one or more cosmetic adjuvants selected from the members of the group consisting of thickeners, buffering agents, chelating agents, preservatives, fragrances, antioxidants, gelling agents, stabilizers, surfactants, emollients, coloring agents, waxes, fungicides, sunscreening agents, sunblocking agents, vitamins, tanning agents, plant extracts, anti-inflammatory agents, anti-oxidants, radical scavenging agents, retinoids, alpha-hydroxy acids, antiseptics, antibiotics, antibacterial agents, antihistamines, soaps, shampoos and deodorants, and mixtures thereof.  
   
   
       14 . A method according to  claim 9  which comprises admixing 1S,9S,5R,6R-5,9-dimethyl-3-oxabicyclo[4.3.0]nonan-2-one in the composition in an amount of from about 0.01% to about 20% weight percent, based on the weight of the whole composition.  
   
   
       15 . A method according to  claim 9  further comprising fabricating the composition in the form of a solution, suspension, cream, ointment, gel, spray, lotion, foam, powder or aerosol.  
   
   
       16 . An article of manufacture selected from the group consisting of (a) an air freshener, (b) a candle, and (c) an article comprising paper, fiber, cloth or fabric, wherein the article comprises 1S,9S,5R,6R-5,9-dimethyl-3-oxabicyclo[4.3.0]nonan-2-one.  
   
   
       17 . An article according to  claim 16  wherein (c) the article comprising fiber, cloth or fabric is selected from the group consisting of sheets, clothing and netting.  
   
   
       18 . A method of fabricating an article that is repellant to an insect or tick, comprising incorporating into the article 1S,9S,5R,6R-5,9-dimethyl-3-oxabicyclo[4.3.0]nonan-2-one.  
   
   
       19 . A method according to  claim 18  wherein the article is selected from the group consisting of (a) an air freshener, (b) a candle, and (c) an article comprising paper, fiber, cloth or fabric.  
   
   
       20 . A method according to  claim 18  wherein (c) the article comprising paper, fiber, cloth or fabric is selected from the group consisting of sheets, clothing and netting.