Phosphate derivatives are disclosed of quinazolinone compounds having structural formula (I) or a pharmaceutically acceptable salt thereof, wherein X' represent hydroxyl, alkyl, alkoxy, or O--Z where Z is a phosphate or phosphate derivative; Y' represents hydrogen, alkyl or an optionally substituted aryl group or optionally substituted aralkyl group; and R' is hydrogen, alkyl, or CH.sub.2 --O--Z where Z is again a phosphate or phosphate derivative; subject to the proviso that if neither X' nor R' contains Z, Y' is an aryl or aralkyl group having an O--Z substituent therein with Z once again being a phosphate or phosphate derivative as hereinabove defined. These compounds are useful as prodrugs for providing active PARP inhibiting substances for medical use in conjunction with a cytotoxic drug or radiotherapy in order to increase the effectiveness of the latter, especially in connection with antitumor treatment. ##STR1##
磷酸盐衍
生物被披露为具有结构式(I)的
喹唑啉酮化合物或其药用可接受的盐,其中X'代表羟基、烷基、烷氧基或O-Z,其中Z是
磷酸盐或
磷酸盐衍
生物;Y'代表氢、烷基或可选择取代的芳基或可选择取代的芳基烷基;R'是氢、烷基或CH.sub.2-O-Z,其中Z再次是
磷酸盐或
磷酸盐衍
生物;但是如果X'和R'都不含Z,则Y'是具有O-Z取代基的芳基或芳基烷基,其中Z再次是
磷酸盐或
磷酸盐衍
生物,如上所定义。这些化合物可用作前药,用于提供用于与细胞毒性药物或放疗一起用于医疗用途的活性PARP抑制物质,以增强后者的效果,特别是在抗肿瘤治疗方面。