Synthesis and biological activities of truncated acridone: Structure-activity relationship studies of cytotoxic 5-hydroxy-4-quinolone

A series of 5-hydroxy-4-quinolone (3) and 5-methoxy-4-quinolone (4) derivatives were synthesized as truncated acridone analogues and evaluated for antitumor and antiherpes activities. Among them 5-hydroxy-8-methoxy-quinolone showed potent antitumor activity (IC50 = 17.7 μM for HL60) which was greater than that of acronycine.