The invention concerns heparanase inhibiting compounds of general formula (I) wherein R represents a hydrogen atom, an hydroxyl radical, a -OSO3- radical, a -O-(C1-C5 alkyl radical or an -O- aralky) radival Z represents a COO radical or a hydroxy) radical X represents -OH or a saccharide unit of formula A, Y represents H, C1-C3 alkyl or a saccharide unit of formula D in fire form or in the form of pharmaceutically aceeptable salts formed with a base or an acid as well as in the form of solvates or hydrates. The derivatives of the invention are useful as medicines.