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Natural Products as Repellents and Insecticides – Charles Cantrell. Callicarpenal Update DEET and Picaridin Analogs (Conclusion of Large SAR Study published in Chemistry and Biodiversity ) Callicarpenal Extraction Study (Needed for Scale-up of Callicarpenal for commercial partners)
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Natural Products as Repellents and Insecticides – Charles Cantrell • Callicarpenal Update • DEET and Picaridin Analogs • (Conclusion of Large SAR Study published in Chemistry and Biodiversity) • Callicarpenal Extraction Study • (Needed for Scale-up of Callicarpenal for commercial partners) • Inula helenium Analogs • Amine Analogs • (Native plant to MS with mosquito actives)
C. americana Compounds at 25 nmole/cm2 vs. Aedes aegypti and Anopheles stephensi
Callicarpenal Michael Addition Products Overall 22 % yield Intermediate not isolated DEET Picaridin Overall 27 % yield
Callicarpenal Sourcing Possibilities • Callicarpa americana • Callicarpa sp. • Verbenaceae species • Methods • Time of Year Simple/Cheap Analog QSAR • Wieland-Miescher • Sclereolide • Labdane to Clerodane • Smaller cpd. build-up • Larger cpd. breakdown
Purity analysis of callicarpenal in hexane, methylene chloride (DCM), methanol, and steam distillation extracts
Seasonal variation of callicarpenal collected from two separate locations in Mississippi
Natural Products as Repellents and Insecticides • Callicarpenal Update • DEET and Picaridin Analogs • Extraction Study • Inula helenium Analogs • Amine Analogs High throughput larvacidal screen – Dr. Becnel’s Group • Day 1: Hatch Aedes aegypti eggs under vacuum • Day 2: Sort 1stinstar larvae to 24-well plates, 5/well; • Add 1ml of water and food; • Add 10 ul of insecticide solution • Day 3: Score bioassay data (dead/total)
Percent mortality of isoalantolactone and alantolactone isomers against A. aegypti larvae
Alantolactone (1a) and isoalantolactone (2a) Micheal addition reaction products.
Four to twelve carbon aliphatic Michael addition substituted reaction products versus larval LC50 activity. Corresponding second order polynomial regression lines are overlaid.
Four to twelve carbon aliphatic Michael addition substituted reaction products versus larval LC50 activity. Corresponding second order polynomial regression lines are overlaid.
2010 Research Plans Additional Michael addition analogs of Inula sp. compounds. Intermedeol SAR study. Work with commercial partner towards commercialization of callicarpenal.
Work of David Wedge and Nur Tabanca • 330 plant extracts • 118 pure compounds • have been submitted for Larvicidal and Adult Topical assays. • 97 plant extracts • 32 pure compounds • have been submitted for Repellent assay.
Aedes aegypti 1st instar Larval Bioassay Dead out of a total of 5 larvae Plant essential oils from Turkish collaborators 181 essential oils have been submitted so far. The most active ones: Requested scale up for more in depth studies
High throughput larval bioassay 41 Euphorbiaceae extracts were screened against Ae. Aegypti. Recently started fractionation
Aedes aegypti 1st instar Larval Bioassay Of the 118 pure compounds Dead out of a total of 5 larvae * * *initiated more in depth studies
Mosquito repellent activity of pure compounds (*) and crude plant extracts * * * * * * * * * * *
Future work • Bioassay-guided fractionation will be performed on most active extracts to identify active compounds • 29 NEW aromatic species and will be examined for repellent and insecticidal activity • 20 fungal endophyte extracts from Brazil will be submitted after preliminary studies are complete • We anticipate several papers, invention disclosures to be sought on most actives with CMAVE, and potential patents