OxyFile #479

The Proton Nuclear Magnetic Resonance Spectroscopy in Following 
Ozone Reaction with Unsaturated Fatty Acids

M. Díaz, F. Hernández, I. Alvarez, H. Velez(1), O. Ledea, J. 

Ozone Research Center, Cuba.
1 - National Center for Scientific Research, Cuba.

Unsaturated fatty acids are essential components of biological 
membranes. In this paper, ozonolysis in vitro of unsaturated fatty 
acids with addition of water or ethanol have been studied by 
Proton Nuclear Magnetic Resonance (1H NMR) at 250 MHz in order to 
investigate if this technique can be used to follow up ozone 
reaction with biological melecules. The ozonolysis of methyl 
oleate (one unsaturated bond) showed that signal intensities from 
formed ozonides were increased with ozone concentration 
increments. However, the signal intensities with addition of water 
were higher than those in ethanol addition. Signal intensities 
from olefinic double bonds were found to decrease with the 
increment in ozonide signals and was present a higher consumption 
of these bonds in water than in ethanol addition. When ozonolysis 
of methyl linoleate (two unsaturated bonds) was performed, signal 
intensities values from ozonide formed in both medium were several 
times greater than those observed with methyl oleate; and signal 
intensities values from olefinic groups disappeared more quickly. 
Vitamin E added in a non-competitive manner results in the same 
observed pattern. Thus, a correspondence in the behavior of these 
signals is observed, and more important is the observation that 
they reflect the proportionality between rate reaction and the 
number of double allylic positions present in the substrate 
molecule. Signals from aldehydes formation were poorly detected at 
lower ozone concentrations. We suggest that the evaluation of 
ozonide and olefinic double bond signals from 250 MHz 1H NMR can 
be an useful tool in assessing ozone reaction with biomolecules 
and perhaps in ozone therapy follow up.

Source: 2nd International Symposium on Ozone Applications
        Havana, Cuba - Mach 24-26, 1997.