| abstract |
ABSTRACT Compounds of the general formulae:- (I) (I') wherein R1 and R2, which can be the same or different, are hydrogen atoms or C1-C5-alkyl radicals, C3-C5-alkenyl radicals or phenyl radicals or, together with the carbon atom to which they are attached, form a saturated or unsaturated C3-C7 ring, R3 and R4, which can be the same or different, are hydrogen atoms, straight-chained or branched C1-C10-alkyl radicals, straight-chained or branched C3-C7-alkenyl radicals, C3-C7-cycloalkyl radicals, C3-C7-cycloalkenyl radicals, phenyl, arylalkyl or hetarylalkyl radicals, R5 is a hydrogen atom or a lower alkyl radical and X is an oxygen or sulphur atom or an imino group, display an immunosuppressive action, and more especially a specifi-cally effective immunosuppressive action thereby having a significant advantage over prior non-specific immuno-suppressives. |