The invention relates to a new medicinal use of a substituted chroman compound of formula I wherein each of R1a and R1b is a substituent selected independently from the group consisting of hydrogen and phenyl optionally substituted with 1-3 substituents selected from the group consisting of halogen, hydroxyl, C1-C4 alkyl, C1-C4 alkoxy, C1- C4 alkanoyloxy, R2a and R2b are hydrogen atoms R3a and R3b is C1-C4 alkyl or R3a and R3b together represent an oxo group or together are an C5-C8 alkylene substituent so that together with the carbon atom to which R3a and R3b are attached form a ring, wherein in the main chain to C5-8 alkylene two non-adjacent carbon atoms are replaced by nitrogen atoms, and said C5-C8 alkylene is optionally substituted by a thioxo group, n is the number of the substituents Rz and is an integer from 1 to 3 inclusive, z is the sequence number of the substituent Rz and is an integer from 4 to n + 3, inclusive, (Rz) is a substituent on the benzene ring attached to a non-nodal carbon atom independently selected from the group consisting of hydroxyl, halogen, C2-C6 alkenyl, C1-C4 alkoxy, C1-4 alkanoyloxy, heterocyclic C4-C7 alkyloxy having an oxygen atom in the ring and optionally substituted with 1- 3 substituents selected from the group consisting of C1-4 alkanoyloxy, phenyl-C3-6 alkenyl optionally substituted in the aryl ring by C1-4 alkanoyloxy and substituted in the chain by an oxo group located on a carbon atom adjacent to the carbon atom involved in the double bond C = C, as tautomer, enantiomer, diastereomer, mixture of enantiomers and/or mixture of diastereomers. A compound of formula I is used as an immunosuppressive drug.
