Spectroscopic characterization of ozonated sunflower oil

Ozonation reactions are very important in vegetable oil chemistry since their ozonation products are involved in antimicrobial effect in therapeutical uses for several microbiological etiology diseases. Information on the spectroscopic characterization of the products generated by ozonolysis of sunflower oil is limited. In the present study ozonized sunflower oil with 650 mmol-equiv/kg of peroxide index is chemically characterized. Ozonation of sunflower oil produced ozonides, aldehydes and hydroperoxides which were identified by H-1, C-13 and two-dimensional H-1 Nuclear Magnetic Resonance (NMR). The virgin sunflower oil and ozonized sunflower oil show very similar 1H NMR spectra except for the resonances at delta = 9.74 and delta = 9.63 ppm that correspond to both triplet ftom aldehydic protons, delta = 5.6 ppm (olefinic signalfirom hydroperoxides), and delta = 5.15 ppm (multiplet from ozonides methylic protons). Other resonance assignments are based on the connectivities provided by the proton scalar coupling constants. These are the following: delta = 3.15 ppm (doublet ftom methylenic group in a position respect to olefinic proton), delta = 2.45 ppm (multiplet ftom methylenic group allylic to ozonides methynic protons) and delta = 1.62 ppm (multiplet methylenic protons in beta position respect to ozonides methynic protons). From the C-13 NMR and H-1-C-13 two-dimensional spectrum of the ozonized sunflower oil, the presence of ozonides was confirmed by the signals delta = 103.43 and delta = 103.49 ppm, respectively. The others new signals found in delta = 42.5 and delta = 42.76 ppm confirm the presence of methylenic carbons front hydroperoxides and ozonides. These results indicate that NMR Spectroscopy can provide valuable information about the amount of reaction compounds of ozonized vegetable oil. From the chemical structural elucidation of ozonated sunflower oily, relevant biochemical and chemical information can be achieved.