PHOTOISOMERIZABLE DERIVATIVES OF DIHYDROFOLATE REDUCTASE INHIBITORS

The present invention relates a compound of formula (I) in Z-isomer form (Z-(l)) or a compound of formula (I) in E-isomer form (E-(l)) wherein: R2 is a radical of formula (II) and of formula (III); X1, X2, X3, X4 and X5 are CR3 and N; Y1 is NH, O and S; each R1, each R3 and R7 are H, halogen, -OH, -O-(C1-C8)alkyl, -N((C1-C8)alkyl)3, -NH((C1-C8)alkyl)2, and -NH2(C1-C8)alkyl; R4, R5 and R6 are H and (C1-C8)alkyl; - - - line indicates the position of R2 radical by which R2 is attached to the adjacent N; and the asterisk indicates a stereogenic carbon atom being in R-isomer, S-isomer and a mixture of R-isomer and S-isomer. It also relates to the compound Z-(l) for use as a medicament; and the compound E-(l) for use in the treatment of a disease or condition mediated by the dihydrofolate reductase, wherein the treatment comprises exposing a compound E-(I) to light irradiation to obtain the compound Z-(l)