Characterization of the Pesticide Properties of Tobacco Bio-oil

Pyrolysis converts biomass such as agricultural and forestry waste into bio-oil. Our interest in the chemical analysis of bio-oil began with tobacco, which is rich in nicotine (a known pesticide). Initial inhibition assays performed with the bio-oil on the Colorado potato beetle, a pest currently resistant to all major insecticides, showed high pesticide activity as expected. Surprisingly, the nicotine-free phases of the bio-oil were also found to be highly lethal to the beetles. Thus, it was hypothesized that some of the alkaloids in plants were preserved during pyrolysis, and gave rise to the activity. Pesticide characteristics of tobacco and coffee bio-oils have been recorded on a number of insects as well as a variety of bacteria and fungi that do not currently respond well to chemical treatment; e.g., Streptomyces Scabies (a common potato scab disease). The current focus is to isolate and identify the components responsible for the pest inhibition, and in turn fully characterize their properties as a novel source of natural pesticides. The procedure begins with a crude separation or fractionation by distillation or extraction to simplify the chemical composition. The fractions are then screened by the activity assay. Analytical separation and mass spectral detection (GC-MS and LC-MS) are then used to generate chemical fingerprints for comparative analysis against libraries of known compounds to identify the active component(s). A mixture of chemical standards is generated from these identified, potentially active, components. This mixture is tested by the activity assay, and chemicals are sequentially removed from this mixture to identify the active components and potential synergistic effects between these components. Thus, a potential pesticide originating from agriculturally-based bio-oil is identified