Rifamycin
Rifamycin is the prime member of the rifamycin family which are represented by drugs that are a product of fermentation from the gram-positive bacterium Amycolatopsis mediterranei, also known as Streptomyces mediterranei. The parent compound of rifamycin was rifamycin B which was originally obtained as a main product in the presence of diethylbarburitic acid. Some small modifications where performed in this inactive compound and with the creation of rifamycin SV there was the first antibiotic used intravenously for the treatment of tuberculosis.  Rifamycin has had several direct derivative products such as rifamycin SV, rifaximin, rifampin and rifamycin CV. All of the derivatives have slight different physicochemical properties when compared to the parent structure.  Rifamycin was further developed by Cosmo Technologies Ltd and approved in November 16, 2018 by the FDA as a prescription drug after being granted the designation of Qualified Infectious Disease Product which allowed it to have a status a priority review. This drug was also sent for review to the EMA in 2015 by Dr. Falk Pharma Gmbh and it was granted a waiver for the tested conditions.