IONIC AND RADICAL REACTIONS

Do livro "The Use of Ozone in Medicine" - autora Dra. Renate Viebahn-Haënsler – 4^th English edition – 2.002 – transcrito por José B. Alvarez – OZONIC

According to these reaction partners O 3 undergoes changes according different mechanisms; in the presence of organic reaction participants, ozone has a markedly selective set of reactions (Hoigné et al 1.983). In principle, radical and ionic reaction mechanisms are possible; see figure 37.

1. Decomposition of ozone in molecular oxygen with system-dependent half-life values (2 O2 ® 3 O 2) in the gaseous state (t _{1 / 2}= 55 minutes n a disposable 50 ml syringe) or also in an aqueous medium, though with considerably delayedhalf life times (t _{1 / 2} = 10 hours in bidistilled water at a 20 ° C / 68 ° F).

2. At pH values < / = 7.4 i.e. under physiological conditions, in the presence of unsaturated fatty acids (UFA) the start of first reaction step is to be found in a 1.3 dipolar addition resulting in peroxide sequel products after breakdown of the double bond of UFA (particularly with an isolated double bound) e.g. phospholipids of the cell membrane.

3. In the presence of OH ^–ions i.e. preferably in an alkaline medium at pH values ³ 8, we are able to reckon with an increasing number of radical reactions forming OH radical and, radical chain reactions as their sequel.

Accordingly in the case of physiological pH values the ionic reaction mechanism is predominant, contributing to further radicals to those already formed. Correspondingly, for example, e.g. vitamin E does not act as an oxidant versus ozone, though this very much the case with vitamin C and those enzymatic antioxidants reacting both ionically and radically (figure 41).

In this way, hydroperoxides as reaction products of ozonolysis (contrary to the auto oxidation of fatty acids with atmosphere oxygen) at phospholipids if the cell membrane are able to enter the intercellular space, at least in part, there to influence cellular metabolism, which can be followed using measurement methods e.g. in the case of red blood cells in the form of a drop in GSH and the increase in ATP and 2,3 DPG, and the immunocompetent cells via activation of nuclear factor NFkB, resulting in the induction and, finally, the release of cytokins.

¶ O + O O