Paragraph B.01. Composition of Oximes
Figure B-I. Formula of Pralidoxime
B-II. Formula of Obidoxime
B-III. Formula of Hagedorn Oximes
B-IV. Reactivation of GB Inhibited Enzyme by Pralidoximes
a. The oximes comprise a group of compounds possessing one or more pyridinium rings and bearing one or more aldoxime groups. A large number of such compounds has been synthesised and are divided into:
(1) Mono pyridinium oximes such as pralidoxime (pyridine-2-aldoxime methyl chloride, PAM Cl, pralidoxime methylsulphonate) (Figure B-I).
(2) Bispyridinium oxides including obidoxime (Toxogonin ®) with the formula as shown in Figure B-II.
b. Recently the new Hagedorn (H) oximes have been synthesised and these include the compounds H16 and HS6 as shown in Figure B-III.
c. The oximes are thought to act by combining with the modified nerve agent molecule and removing it from the acetylcholinesterase enzyme. They also have other pharmacological effects which may contribute to their efficacy.
d. The sequence of reactions shown in Figure B-IV represents the reactivation of GB inhibited enzyme by pralidoxime.