A comparison of the efficacy of a new asymmetric bispyridinium oxime BI-6 with currently available oximes and H oximes against soman by in vitro and in vivo methods

A comparison of reactivating efficacy of newly developed oximes (K074, K075) and currently available oximes (obidoxime, HI-6) in cyclosarin-and tabun-poisoned rats

“…On the other hand, the number of aldoxime groups is not so important. The oxime HI-6 has only one oxime group but it is significantly more efficient at reactivating soman-and cyclosarin-inhibited AChE than bispyridinium oximes with two aldoxime groups such as obidoxime, methoxime or trimedoxime [25,26]. The chain linking the two quaternary nitrogens in bispyridinium oximes exerts a great effect on reactivating ability, although this part of the oxime reactivator molecule does not play any role in the dephosphorylation process.…”

Unequal Efficacy of Pyridinium Oximes in Acute Organophosphate Poisoning

“…Thus far, numerous attempts had been made to improve the antidotal properties of the conventional mono-and bis-pyridinium mono(di)-oximes by modifying their structure as well as by the introduction of other heterocyclic systems, such as imidazolium, quinuclidinium, pyridinium-imidazolium, pyridinium-quinuclidinium, and quinuclidinium-imidazolium compounds. 26,[63][64][65][66][67][68][69] Additionally, recent experimental studies conducted with 1,1'-methylene-bis(4-(hydroxyimino)methyl) pyridinium dibromide (MMB-4) showed that, compared to HLö-7 and HI-6, MMB-4 was a less potent reactivator of AChE inhibited by sarin, several sarin analogues, soman, VX, VR or CVX. 3,70 Therefore, despite intensive research activities on this topic, PAM-2, TMB-4, LüH-6, HI-6 and HLö-7 have remained dominant among oximes in experimental work.…”

A Comparison of the Potency of Newly Developed Oximes (K347, K628) and Currently Available Oximes (Obidoxime, HI-6) to Counteract Acute Neurotoxic Effects of Tabun in Rats

“…administration of tabun at a lethal dose, nevertheless, their neuroprotective efficacy is not satisfactory (14,15,17). The oxime HI-6, developed and introduced by some countries for the antidotal treatment of severe acute soman poisonings (4,12), was found to be significantly less efficacious to counteract tabun-induced acute neurotoxicity than obidoxime (15). The unsatisfactory efficacy of the above mentioned oximes in eliminating tabun-induced acute neurotoxicity can be explained by the low potency of oximes in reactivating tabun-inhibited AChE in vitro and in vivo (10,20,26,30).…”