12-[3,4-Dihydroxy-6-(hydroxymethyl)-5-methoxyperhydro-2H-pyran-2-yl]-3,9-dibromoindolo[2,3-a]3-pyrrolino[3,4-c]carbazole-5,7-dione AIDS-079986 AIDS079986 Indolocarbazole Rebeccamycin analog