A compound of formula (I): ##STR1## wherein: R represents hydrogen, optionally substituted alkyl or alkenyl, R.sub.1 to R.sub.8, which may be identical or different, each represents hydrogen, optionally substituted alkyl, hydroxy, acyloxy, optionally substituted amino, carboxy, optionally substituted alkoxy, or alkenyloxy, or one of R.sub.1 to R.sub.8 forms, with another of R.sub.1 to R.sub.8 that is adjacent, an alkylenedioxy group, X represents oxygen or NR.sub.16 wherein R.sub.16 represents hydrogen, alkyl, aryl or arylalkyl, R.sub.9 represents hydrogen, aryl, heteroaryl, or optionally substituted, saturated or unsaturated alkyl, an isomer thereof, or an addition salt thereof with a pharmaceutically acceptable acid or base. Medicinal products containing the same which are useful as anti-cancer agents.
