A new indolocarbazole compound, NB-506 (1), modified at the glucose group yielded a beta-D-glucopyranoside, J-107,088 (2), which showed potent anticancer activity. A beta-D-ribofuranoside, J-109,534 (3), was found to be 6 times more potent than J-107,088 at inhibiting topoisomerase I.
Indolopyrrocarbazole derivatives such as exemplified by the following compound, ##STR1## have excellent antitumor activity as evidenced by in vitro proliferation inhibiting activity against mouse leukemia cell, human gastric cancer cell, human lung cancer cell and human colon cancer cell.
6-N-Amino analogues of NB-506 [6-N-formylamino-12,13-dihydro-1,11-dihydroxy-13-(beta-D-glucopyranosyl)-5H-indolo [2,3-a]pyrrolo[3,4-c]carbazole-5,7(6H)-dione] (3b) were synthesized and tested with respect to topoisomerase inhibition, cytotoxicity and anticancer effects. Among them, a 1,3-dihydroxypropane analogue (J-109,404, St) showed more than ten times more potent anticancer activity in MKN-45 human stomach cancer cells implanted in mice than NB-506. (C) 1999 Elsevier Science Ltd. All rights reserved.
Processes for the preparation of indolopyrrolocarbazole derivatives