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Extraction of Potential Chemical Attractants from the Black-eyed Susan. RoJenia Judkins Ball State University Chemistry Department Muncie, IN 47306. Goal of Research.
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Extraction of Potential Chemical Attractants from the Black-eyed Susan RoJenia Judkins Ball State University Chemistry Department Muncie, IN 47306
Goal of Research We aim to identify the volatile compounds in inflorescences of Rudbeckiahirta, that may be responsible for the olfactory attraction of the crab spider, Misumenoidesformosipes, to this plant.
M. formosipesMating System Sub-adult females commonly forage from the inflorescences of R. hirta. In order for copulation to occur adult males search their vegetatively complex habitat for the foraging locations of these females and ultimately locate the females.
Exploitation of Floral Signals by Crab Spiders • Males will locate inflorescences despite the absence of a female • Males were able to locate inflorescences without the presence of visual cues • Thus, these studies provide strong evidence that males detect and navigate towards inflorescences primarily based on floral chemistry
Extraction Methods Comparison of various liquid-solid extraction techniques used in the analysis of plant metabolites USE=ultrasonic extraction ASE= accelerated solvent extraction MAE= microwave-assisted extraction SFE= supercritical fluid extraction
Ultrasonic Extraction • 60 ml of 1:2 solution of hexane:diethyl ether • 10g of cut up inflorescences • Sonicated for 30 minutes in the dark • Approximately .4g of extract was collected
Solvent System • 100% Dichloromethane • Heavy spot on solvent line as well as spot at application line (as well as other spots between) • 95% Dichloromethane • Separated components near the application line but not at the solvent line • 95% Hexane • Separated components at the solvent line, but not at the application line
Flash Chromatography We used solvent mixtures of: • 95% hexane:5% dichloromethane • 95% dichloromethane:5% hexane • 100% dichloromethane • A methanol wash of the column A total of 33 15ml fractions were collected
Thin Layer Chromatography • 95% Hexane fractions • No components were observed • Pooled together based on color • 95% Dichloromethane fractions • All were pooled together due to similar color • 100% Dichloromethane fractions • Pooled together based on similar Rf values • Remaining were pooled together based on color
Experimental Approach Bioassay Ultrasonic Extract (hexane:diethyl ether) Bioassay Flash Chromatography (Silica Column) 95%DCM 100%DCM Methanol 95%Hexane TLC Further separation Identification of Attractant
Bioassay Trials An exact binomial calculation was used for each trial. This P value represents the probability of getting the results we obtained in comparison to chance.
100% DCM Pool Further separated using flash chromatography TLC results reveal 2 potentially different compounds
Plan for Future Research • Myself • Future Researchers Separate components in the 100% DCM pool Removal of Hexane Identify the two compounds using Infrared Spectroscopy, NMR, and/or GC-MS Run bioassays on pooled fractions to obtain statistically sound results Separate 100% DCM pool and run bioassays