Arsenic Compounds after Ehrlich

After the death of EhrKch in 1915, research into the organoarsenicals continued, and it was discovered that, in the body, Salvarsan was oxidized to oxophenarsine hydrochloride 4 (marketed as Mapharsen ). Since this compotmd was stable in air, it gradually replaced Salvarsan for therapeutic use, to the point where it became the predominant organoarsenic medicine during the 1930s. 

Mapharsen and other arsenic analogs remained in therapeutic use throughout the 1940s but were gradually replaced by penicillin. This does not mean that organoarsenic compounds have completely disappeared from the market. Indeed, they are still employed in veterinary medicine for their antiparasitic properties, and their antiviral activity has recently been studied. 

Organomercury compounds are considered of little therapeutic interest today, although mercurochrome and merthiolate are stiU used as mild local antiseptics. This underlines the common tendency for compounds of this type they are normally prescribed as external antibiotics rather than for internal use. In fact most cases of organometaUic poisonings are due to ingestion of methylmercury compounds either from marine organisms or from treated seed grain [44]. 

The Current Re-evaluation Considerations of Efhcacy, Toxicity and Selectivity 

In addition to the explosion in synthetic potential given to organometaUic chemistry by the wide range of new functional groups discovered in the second half of the 

---

Although the element is a metalloid, the long, brittle, crystals have a metallic shine. The white, tasteless oxide (arsenic trioxide As203) has been famous and notorious ("inheritance powder") even after centuries traces can be found in bodies. The arsenic compound "Salvarsan" was first used by Paul Ehrlich for the treatment of syphilis — the start of chemotherapy. Popular today as a semiconducting material. Component of LEDs (light-emitting diodes) and lasers. Arsenic hardens lead, used earlier in letter-press printing, today only for lead shot. 

---