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.