Characterization by NMR of ozonized methyl linoleate

Abstract

In the present study ozonized methyl linoleate with peroxide index of 1,800 mmol-equiv kg-1 was chemically characterized. Ozonation of methyl linoleate produced hydroperoxides, ozonides and aldehydes which were identified by 1H and 13C NMR two-dimensional. The standard methyl linoleate and ozonized methyl linoleate shown very similar 1H NMR spectra except for the signals at δ 9.7 and δ 9.6 that correspond to aldehydic hydrogen, δ 5.7 and δ 5.5 (olefinic signals from hydroperoxides) and δ 5.2 ppm (multiplet from ozonides methynic hydrogen). Other resonance assignments are based on the connectivities provided by the hydrogen scalar coupling constants. These results indicate that NMR spectroscopy can provide valuable information about the amount of formed oxygenated compounds in the ozonized methyl linoleate in order to use it to follow up ozone therapy and chemistry of ozonized vegetable oil. ©2007 Sociedade Brasileira de Química.