148236-03-7 25-Deacetyl-3'-hydroxy-5'-(4-isobutyl-1-piperazinyl)benzoxazinorifamycin 25-Desacetyl KRM-1648 25-Desacetyl-rifalazil 3'-Hydroxy-5'-piperazinylbenzoxazinorifamycin deriv AIDS-097976 AIDS097976 KRM-1671