A Survey of Synthetic Routes and Antitumor Activities for Benzo[g]quinoxaline-5,10-diones

Anthracycline antibiotics play an important role in cancer chemotherapy. The need to improve their therapeutic index has stimulated an ongoing search for anthracycline analogs with enhanced properties. This review aims to summarize the common synthetic approaches to benzo[g]quinoxaline-5,10-diones and their uses in heterocyclic chemistry. Because of the valuable biological activities of the 1,4-diazaanthraquinone compounds, a summary of the most promising heterocyclic quinones is provided together with their antitumor properties.

Synthesis and cytotoxic activities of 2-alkyl-2,3-dihydro-1H-2,6,9-triazacyclopenta[b]anthracene-5,10-diones

A series of 2-alkyl-2,3-dihydro-1H-2,6,9-triazacyclopenta[b]anthracene-5,10-diones (4a-f) were synthesized and their in vitro cytotoxic activities were evaluated against six human cancer cell lines (HCT15, SK-OV-3, A549, SNB19, MCF7 and MCF7/ADR). A number of compounds including 4c and 4d showed 2-180 times more potent cytotoxic activity than doxorubicin against all human cancer cell lines tested. Furthermore, these compounds retained considerable cytotoxic activity against the doxorubicin-resistant cell line MCF7/ADR, implying their therapeutic potential to treat doxorubicin-resistant tumors.

Synthesis and cytotoxic activities of 8-alkyl or 8-aryl-8,9-dihydro-7H-isoindolo[5,6-g]quinoxaline-7,9-diones

A series of 8-alkyl- and 8-aryl-8,9-dihydro-7H-isoindolo[5,6- g]quinoxaline-7,9-diones were synthesized using sultine chemistry as a key step in good yield. These compounds were evaluated for their in vitro cytotoxicity against six human cancer cell lines (HCT15, SK-OV-3, A549, SNB19, MCF7 and MCF7/ADR).