DEVELOPMENT OF A NOVEL ALL NATURAL TICK AND INSECT REPELLENT, BIOUD, AS A DEET REPLACEMENT AND FOR USE ON COTTON FABRIC

摘要

Novel aromatic and aliphatic organic acids, esters and ketones were synthesized and assayed as repellents for ticks. E-7-(cyclohexyl)hept-4-enoic acid (CHEA), E-7-phenylhept-4-enoic acid (PHEA), ethyl E-7-(cyclohexyl)hept-4-enoate (CHEN) and ethyl E-7-phenylhept-4-enoate (PHEN) had repellent activity against the soft tick, Ornithodoros parkeri (Acari: Argasidae) in a two-choice bioassay. PHEN, an aromatic organic ester, was the most active. 2- undecanone, a natural product found in the trichomes of wild tomatoes, was found to mimic our lead chemistry and was active as a repellent at 50 μg/cm 2 . Since this compound is an already known natural botanical with a proven safety record including being approved as a food additive, formulation studies wereconducted to optimize its volatility and maximize its repellent activity against ticks and mosquitoes when applied to human skin. Combining undecanone with proprietary emulsions from HOMS LLC, we were able to develop BioUD. BioUD30 and BioUD8 (30 and 8%undecanone, respectively) was a repellent to the American dog tick, Dermacentor variabilis (Acari: Ixodidae), 2.5 h after applications on the skin of human subjects. In field studies in two different habitats (forest and marsh), 99% repellency was found4.5 h after application to the skin of human subjects for a population of mosquitoes comprised of mixed species. BioUD8 at 6 h after application was better than OFF Botanicals with 10% PMD and equivalent to OFF with 15% DEET. Application of 20 μl BioUD30 silicon (5.88mg undecanone) to 19.63 cm 2 of cotton fabric repelled on average >90% of D. variabilis ticks in a two-choice bioassay 5 d after application, suggesting that it effectively binds to cotton fabric. The repellent was active on cloth up to 7d. The submission of BioUD for US EPA registration is expected in early 2006. The product will be marketed by HOMS LLC as a DEET alternative. BioUD will be all natural and non-flammable unlike many DEET products, with the potential of being organicallycertified.