Tigecycline is a glycylcycline antibiotic developed by Francis Tally and marketed by Wyeth under the brand name Tygacil. It was developed in response to the growing prevalence of antibiotic resistance in bacteria such as Staphylococcus aureus and Acinetobacter baumannii.This antibiotic is the first clinically available drug in a new class of antibiotics called the glycylcyclines. It is structurally similar to the tetracyclines in that it contains a central four-ring carbocyclic skeleton and is actually a derivative of minocycline. Tigecycline has a substitution at the D-9 position which is believed to confer broad spectrum activity. Tigecycline is bacteriostatic and is a protein synthesis inhibitor by binding to the 30S ribosomal subunit of bacteria and thereby blocking entry of Aminoacyl-tRNA into the A site of the ribosome during prokaryotic translation.