Figure 4.

Cytotoxicity correlates with N,N-dimethylation and efficiency of histone eviction. (A) Histone eviction speed (time at which 25% of the initial signal is reduced) versus IC₅₀ of the various hybrid compounds is plotted. Two-tailed Spearman r correlation, *P < 0.05. (B) Zoom-in of data plotted in (A). (C) N,N-Dimethylation of the first sugar over no methylation gives improved IC₅₀ in K562 cells (1 versus 3/2 versus 4/5 versus 7/6 versus 8/9 versus 11/10 versus 12). IC₅₀ is plotted for the corresponding hybrid structures without (no; N) and with (yes; Y) N,N-dimethylation. The fold change of IC₅₀ improvement as a result of N,N-dimethylation is indicated above the bars. IC₅₀ could not be determined for compounds 2, 5, and 6 (gray bars) and was therefore depicted as the highest concentration tested (10 μM).