Novel diarylamides and diarylureas with N-substitution dependent activity against medulloblastoma

Medulloblastoma - highly aggressive and heterogeneous tumours of the cerebellum - account for 15-20% of all childhood brain tumours, and are the most common high-grade childhood embryonal tumour of the central nervous system. Herein, potent in vitro anticancer activity against two established medulloblastoma cell lines of the sonic hedgehog subgroup, namely DAOY (p53 mutant) and ONS-76 (p53 wild type), has been achieved. A number of first-generation diarylamides and diarylureas were evaluated and activity is likely to be, in-part, conformation-dependent. The most active compound from this first-generation set of compounds, 1-naphthyl derivative 4b, was selected and a second-generation of compounds were optimised and tested for activity against the medulloblastoma cell lines. This process resulted in drug-like compounds with up to sixty times the activity (sub-micromolar) of the first-generation - thus providing potent new leads for further study.

N,N′-Bis(4-bromophenyl)-N,N′-dimethylurea

The structure of the title compound, C15H14Br2N2O, at 180 K has monoclinic (P21/n) symmetry. It was obtained unexpectedly from the decomposition of the parent 4-bromo-N-tert-butoxycarbonyl-N-methyl-aniline. It exhibits an `endo' conformation with angles between the two aromatic rings slightly lower than the average values found for similar compounds on the Cambridge Structural Database. In the crystal, C—H...O hydrogen bonds and short Br...Br halogen bonds [3.444 (1) Å] are observed.

Design, Synthesis, and in vitro and in vivo Evaluations of (Z)-3,4,5-Trimethoxystyrylbenzenesulfonamides/sulfonates as Highly Potent Tubulin Polymerization Inhibitors

Newer therapeutics can be developed in drug discovery by adopting the strategy of scaffold hopping of the privileged scaffolds from known bioactive compounds. This strategy has been widely employed in drug-discovery processes. Structure-based docking studies illustrate the basic underlying concepts and reveal that interactions of the sulfonamide group and hydrophobic interactions are crucial. On the basis of this strategy, over 60 synthetic analogues were synthesized and evaluated for their cytotoxicity against the NCI panel of 60 human cancer cell lines; the majority of these compounds exhibited promising cytotoxicity with GI₅₀ values ranging between 18 and 50 nm. Among these compounds, (Z)-N-[2,3-dimethoxy-5-(3,4,5-trimethoxystyryl)phenyl]-4-methoxybenzenesulfonamide (7 a) and (Z)-N-[2-hydroxy-3-methoxy-6-(3,4,5-trimethoxystyryl)phenyl]-4-methoxybenzenesulfonamide (9 a) were found to be potent. Similar results were obtained against three human cancer cell lines with IC₅₀ values ranging between 0.04 and 3.0 μm. Studies aimed at elucidating the mechanism of action of these new analogues revealed that they inhibited the in vitro polymerization of tubulin and disorganized the assembly of microtubules in HeLa and MCF-7cancer cells. Lead compounds 7 a and 9 a displayed notable in vivo antitumor activity in a HeLa tumor xenograft model. Our studies have resulted in the identification of a scaffold that can target tubulin polymerization, which should have significant potential toward the development of new antitumor drugs.