Design and synthesis of anticancer 1-hydroxynaphthalene-2-carboxanilides with a p53 independent mechanism of action

Abstract

A series of 116 small-molecule 1-hydroxynaphthalene-2-carboxanilides was designed based on the fragment-based approach and was synthesized according to the microwave-assisted protocol. The biological activity of all of the compounds was tested on human colon carcinoma cell lines including a deleted TP53 tumor suppressor gene. The mechanism of activity was studied according to the p53 status in the cell. Several compounds revealed a good to excellent activity that was similar to or better than the standard anticancer drugs. Some of these appeared to be more active against the p53 null cells than their wild-type counterparts. Intercalating the properties of these compounds could be responsible for their mechanism of action.

Figure 1

Small molecule anilides revisited as anticancer agents.

Figure 2

Design of the target amides. Compounds with an anticancer activity provided amine-derived fragments, which were further divided into substituents. The final structure was a combination of all of the fragments.

Figure 3

Synthesis of ring-substituted 1-hydroxynaphthalene-2-carboxanilides 1–8d. Microwave irradiation (MW) conditions: 120–130 °C; 500 W; 50 minutes R = H, OCH₃, F, Cl, Br, CF₃, NO₂.

Figure 4

Number of individual compounds that appeared in the test set within >0.6 and >0 for the HCT116^+/+ potency of the hydroxynaphthanilide derivatives using the CoMSA method.

Figure 5

The morphological changes of the HCT116 p53^+/+ (A) and HCT116 p53^−/− (B) cells after a 48-hour treatment with 5u, 5s and 7f. The cells were stained with AO/EB to indicate apoptosis. The cells that had been treated with anilides showed early apoptotic features – green and yellow cells (green dots in the nuclei indicate chromatin condensation and nuclear fragmentation) and late apoptotic cells – orange cells with condensed and fragmented nuclei. Scale bars = 50 μm.

Figure 6

Influence of the active anilides and DOX on the activation of the p53/p21 system in the HCT116 cells (A). A densitometric analysis of the expression of the p21 protein normalized to GAPDH. The results are the mean ± SD of three independent experiments (B). Uncropped expositions are presented in Figure S5 in the Supplementary Information.

Figure 7

CoMSA IVE-PLS monitored for the 68/34 training/test set samplings. The plots show the spatial areas with the strongest influence to the HCT116^+/+ activity. Colors coding the sign of this impact (a). Four possible combinations of the mean charge and correlation coefficient are color coded (b). Compound 1 as a reference molecule was plotted in two different orientations.