Fig. 2: Photochemical and biological evaluation of modulators 3-5.

a Structures and photoisomerization scheme of modulators 3-5. b Cis-to-trans thermal isomerization in cell culture medium followed in the dark. Photostationary states (PSSs, pie charts) were reached upon irradiation of DMSO solution (2 mM, 25 °C) with UV light (λ_max = 365 nm) and subsequent dilution in the cell culture medium to obtain the final concentration of 40 µM. The amount of the cis-isomer is shown in pie chart (purple). After 12–14 h in the dark (gray background), blue light (λ_max = 450 nm, blue rectangle) was applied for 8 min to confirm the presence of the remaining cis-isomer and provided the cis-to-trans ratio. c Photo-modulation of the CKIα inhibition, shown as the dose-response curve for the inhibitor kept in the dark (black line) and irradiated with UV light (purple line) before addition to the enzymatic reaction mixture (30 min) and during the assay (3 h). d Luminescence rhythm profiles (average of n = 6) and period-changes of U2OS reporter cells relative to DMSO control, applied with the compounds kept in the dark (black lines) or irradiated with UV light (purple line). Data for longdaysin and DMSO-treated cells are shown in Supplementary Fig. 24a, b, respectively. Luminescence is given in arbitrary units. n = 2 biologically independent samples for the enzymatic assay (c) and n = 6 biologically independent samples for the cellular assay (d). Two-way ANOVA followed by a Sidak’s multiple comparisons test was used for statistical analysis. P value is shown in the figure.