Spectroscopic Characterization ofOzonated Sunflower Oil

摘要

Ozonation reactions are very important in vegetable oil chemistry sincerntheir ozonation products are involved in antimicrobial effect inrntherapeutical uses for several microbiological etiology diseases.rnInformation on the spectroscopic characterization of the productsrngenerated by ozonolysis of sunflower oil is limited. In the present studyrnozonized sunflower oil with 650 mmol-equiv/g of peroxide index isrnchemically characterized. Ozonation of sunflower oil producedrnozonides, aldehydes and hydroperoxides which were identified by 1H,rn13C and two-dimensional C 1H Nuclear Magnetic Resonance (NMR). Thernvirgin sunflower oil and ozonized sunflower oil show very similar 1HrnNMR spectra except for the resonances at δ = 9.74 and δ = 9.63 ppmrnthat correspond to both triplet from aldehydic protons, δ = 5.6 ppmrn(olefinic signal from hydroperoxides), and δ = 5.15 ppm (multipletrnfrom ozonides methylic protons). Other resonance assignments arernbased on the connectivities provided by the proton scalar couplingrnconstants. These are the following: δ = 3.15 ppm (doublet fromrnmethylenic group in α position respect to olefinic proton), δ = 2.45rnppm (multiplet from methylenic group allylic to ozonides methynicrnprotons) and δ = 1.62 ppm (multiplet methylenic protons in β positionrnrespect to ozonides methynic protons). From the 13C NMR and 1H-13Crntwo- dimensional spectrum of the ozonized sunflower oil, the presencernof ozonides was confirmed by the signals δ = 103.43 and δ = 103.49rnppm, respectively. The others new signals found in δ = 42.5 and δ =rn42.76 ppm confirm the presence of methylenic carbons fromrnhydroperoxides and ozonides. These results indicate that NMRrnSpectroscopy can provide valuable information about the amount ofrnreaction compounds of ozonized vegetable oil. From the chemical