Synonyms: Krm 1687;KRM-1687;133698-17-6;3'-Hydroxy-5'(S)-(4-sec-butylpiperazinyl)benzoxazinorifamycin;Rifamycin VIII, 1',4-didehydro-1-deoxy-1,4-dihydro-3'-hydroxy-5'-(4-(1-methylpropyl)-1-piperazinyl)-1-oxo-, (5'(S))-;Rifamycin VIII, 1',4-didehydro-1-deoxy-1,4-dihydro-3'-hydroxy-5'-[4-(1-methylpropyl)-1-piperazinyl]-1-oxo-, [5'(S)]-; 3'-Hydroxy-5'(S)-(4-sec-butylpiperazinyl)benzoxazinorifamycin