Valnemulin is a semi-synthetic pleuromutilin prepared by sequential reaction of pleuromutilin tosylate with 2-amino-1,1-dimethylethylthiol, coupling the free amine with a protected valine and then deprotection to provide the final product. Valnemulin is a broad spectrum antibiotic used to control gastrointestinal infections in animals and shows no cross resistance to other antibiotic classes. Like all the pleuromutilins, valnemulin inhibits protein synthesis by binding to domain V of 23S RNA.