A series of 5-hydroxy-4-quinolone (3) and 5methoxy-4-quinolone (4) derivatives were synthesized as truncated acridone analogues and evaluated for antitumor and antiherpes activities. Among them 5-hydroxy-smethoxy-quinolone showed potent antitumor activity (ICse = 17.7 KM for HL60) which was greater than that of acronycine. 1997 Elsevier Science Ltd.