Ozone, Oleanolic acid, Epicuticular, Wax, Grape
This thesis presents a reproducible method for quantifying the amount of lactone formed as a result of the reaction between tropospheric ozone and oleanolic acid found in the epicuticular wax of grapes over the course of the summer. This work is intended to build upon the findings made by Smith, Navarro, and Romero, who contributed to the discovery of the structure and the presence of the lactone product. Using high performance liquid chromatography-quadrupole-time of flight mass spectrometry (HPLC-QToF-MS), the estimated percentage of oleanolic acid converted into lactone was 1.58-2.88%, showing comparable results between the wax of green and red grapes. These numbers may contribute to current knowledge of ozone deposition, accounting for how much ozone gets deposited upon the epicuticular wax of grape skins. Lactone concentrations were also quantified in samples originally containing purified oleanolic acid that were left both inside the fume hood in the laboratory and outside in ambient conditions. This was to determine if the lab was an acceptable environment to keep a control sample. The average concentration of lactone formed in the fume hood is comparable with that of the grape waxes, suggesting that there are similar ozone levels both inside and outside of the building, and that control samples must be protected from the air inside of the lab.
Department 1 Awarding Honors Status
Ramirez, B. (2021). The Direct Reaction of Tropospheric Ozone with Oleanolic Acid in the Epicuticular Wax of Grape Skins (Undergraduate honors thesis, University of Redlands). Retrieved from https://inspire.redlands.edu/cas_honors/1014
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