Organic arsenicals development

CHjSH CHSH-CHjOH. Usually obtained as an oil, m.p. 77 C. Developed as an antidote to poisoning by organic arsenicals by external application, it is of use in poisoning by Hg, Cu, Zn, Cd but not Pb. It acts by forming a chelate with the metal and so removing it from the system. 

A novel interface to connect a ce system with an inductively coupled plasma mass spectrometric (icpms) detector has been developed (88). The interface was built using a direct injection nebulizer (din) system. The ce/din/icpms system was evaluated using samples containing selected alkah, alkaline earths, and heavy-metal ions, as well as selenium (Se(IV) and Se(VI)), and various inorganic and organic arsenic species. The preliminary results show that the system can be used to determine metal species at ppt to ppb level. 

Dimercaprol (BAL, British Anti-Lewisite) was developed in World War 11 as an antidote against vesicant organic arsenicals (B). It is able to chelate various metal ions. Dimercaprol forms a liquid, rapidly decomposing substance that is given intramuscularly in an oily vehicle. A related compound, both in terms of structure and activity, is di-mercaptopropanesulfonic acid, whose sodium salt is suitable for oral administration. Shivering, fever, and skin reactions are potential adverse effects. 

WHO. (2000). Towards an Assessment of Socioeconomic Impact of Arsenic Poisoning in Bangladesh. World Health Organization, Sustainable Development and Healthy Environments, WHO/SDE/WSH/00.4, 1-42. 

Arsenicals are considered a threat, not so much from large nation states but fi om smaller, less developed nations and/or by terrorist organizations. The relative ease of production coupled with their effectiveness against an unprotected population make organic arsenicals a continued threat in the 21st century. This chapter describes the human health aspects of arsine, organic arsenicals, and inorganic arsenic, and the current status of development of suitable therapeutic measures. 

The fact that administration of organic sulfhydryl compounds can both reverse the toxicity of these arsenic drugs and their activity tends to support this simple idea. It seems almost incredible that the organism can develop resistance to such a nonselective protoplasmic poison as arsenic, but it does, apparently by decreased uptake. 

Plants treated with organic arsenic compounds first show symptoms of chlorosis and then cease to grow. They gradually bKxime brown and finally wither. Action develops slowly, increased temperature accelerating the action. 

The importance of organic arsenic compounds as antiprotozoals faded with the development of penicillin. Because of the toxicity of arsenic compounds this branch of chemistry lost its importance for the next 40 years. 

Hair is simple to collect and analyze, but arsenic levels in hair do not respond rapidly to exposure. Blood both is difficult to collect and does not give a consistent or rapid enough response to As exposure of an organism. Thus, even with the attendant collection problems, urine is the most practical index to the exposure of forest workers to the organic arsenical herbicides. Unfortunately, the pharmacokinetics of these herbicides have not been fully developed for dermal exposure, and there are indications that urine is not the sole excretory route. Thus, estimates of exposure based only on As excretion in urine may be only 30% of actual exposure levels (2 8). 

Quintas-Cardama A, Verstovsek S, Freireich E, Kantarjian H, Chen YW, Zingaro R. Chemical and clinical development of darinaparsin, a novel organic arsenic derivative. Anticancer Agents Med Orem 2008 8(8) 904-9. 

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