Pleuromutilin is a diterpene produced by several species of basidomycete, notably the genus Pleurotus, discovered in 1951. Pleuromutilin is a potent and highly selective antibiotic active against a range of Gram positive bacteria, with no cross resistance to existing antibiotic classes due to its unique mode of action. Pleuromutilin inhibits protein synthesis by binding to domain V of 23S rRNA and this has led to the development of many semi-synthetic analogues as new generation antibiotics, such as tiamulin and retapamulin.