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W kierunku poznania reakcji przeniesienia fosforylu : wykorzystanie biocydów fosforoorganicznych w badaniach

Przychodzeń W.

Wiadomości Chemiczne

2008

[Z] 62, 3-4

269-295

Among organophosphorus biocides (OPB), VX is the most toxic, but multi-ton production of less toxic OP pesticides, solvents, plasticizers, and engine anti-wear additives as well as their precursors can also have a detrimental impact on our health. V-gases have been feared as the "nuclear weapon" of poorer nations and terrorist groups because their manufacturing is relatively simple and the starting materials are readily available. Comparison of toxicity of OPB, of both synthetic and natural origin is presented in Table 1. It is well-known that some OBP were used in ophtalmology. Rationally designed OBP can be active in treatment of Alzheimer or Parkinson disease [9-11] or as ?-lactamase inhibitor in the future [12]. The extreme toxicity of V-gases often mandates research laboratories to employ safer model compounds called simulants instead of the actual compounds. Some examples of recently involved simulants are presented (Fig. 3) and the influence of their structure on reactivity is reported [13-14]. Many efforts have recently been performed in order to find new and effective methods of detection of OPB and their degradation products (Ch. 4). Although sophisticated chromatographic techniques are involved [15], they are not optimal for rapid detection. The most promising methods seem to be antibody-based recognition [18] and the use of chemical [17] and biological sensors [19]. A great deal of work is devoted to develop efficient methods capable of eliminating persistent OPB under comparatively mild conditions. Chemical methods with the emphasis on nucleophile promoted hydrolysis are the most preffered reaction. Especially, supernucleophilic reagents facilitate OPB hydrolysis and some of them act as strong oxidants [25-27]. Otherwise, enzyme-like systems including micelles and microemulsions have been used in decomposition by nucleophiles. It was found that OPB methanolysis can be accelerated with the use of lanthanium and cupric ions by a factor of 109 [29-32]. The use of reactive polymers, which are prone to transesterification [28] is quite a novel approach to the detoxification of OPB. This methodology allows immobilizing phosphoric residue on polymeric particles and completely removes OPB from their solutions (Fig. 6). Detoxification of VX is an extremely serious, yet unsolved scientific problem. Its hydrolysis (and oxidation) is a relatively slow process and proceeds to the formation of other toxic compounds (Fig. 5) [22]. A number of groups have looked at the creation of catalytic antibodies which can be used for the degradation of VX [13, 37-38]. Haptens bearing amine oxides, phosphorane and ?-hydroxyphosphinate structures have been designed for the selection of antibodies in order to hydrolyse paraoxone and VX, respectivily (Fig. 8 and 9). Also, considerable efforts have been made concerning the hydrolysis of V-gases with enzymes [33-36]. Until now, reactivation of AChE is realized by only one family of antidotes known as pyridinum oximes although some improvements of their structure have been made [39-41] (Fig. 10). Studies of uncatalyzed [44, 48-52] and enzymatic phosphoryl transfer (PT) and thiophosphoryl group transfer reaction [43-47] have been undertaken in various laboratories in an effort to understand the mechanism of this important biological process. Additionally, few examples of improvements in OPB synthesis are presented (Fig. 13) which could have the influence on the progress in OPB-based research.