Synthesis and evaluation of 1-(substituted)-3-prop-2-ynylureas as antiangiogenic agents

Synthesis and structure-activity relationship study of pyrrolidine-oxadiazoles as anthelmintics against Haemonchus contortus

Parasitic roundworms (nematodes) are significant pathogens of humans and animals and cause substantive socioeconomic losses due to the diseases that they cause. The control of nematodes in livestock animals relies heavily on the use of anthelmintic drugs. However, their extensive use has led to a widespread problem of drug resistance in these worms. Thus, the discovery and development of novel chemical entities for the treatment of parasitic worms of humans and animals is needed. Herein, we describe our medicinal chemistry optimization efforts of a phenotypic hit against Haemonchus contortus based on a pyrrolidine-oxadiazole scaffold. This led to the identification of compounds with potent inhibitory activities (IC₅₀ = 0.78-22.4 μM) on the motility and development of parasitic stages of H. contortus, and which were found to be highly selective in a mammalian cell counter-screen. These compounds could be used as suitable chemical tools for drug target identification or as lead compounds for further optimization.

Synthesis and cytotoxic evaluation of some novel quinoxalinedione diarylamide sorafenib analogues

A series of novel sorafenib analogues containing a quinoxalinedione ring and amide linker were synthesized. A total of 9 novel compounds in 6 synthetic steps were synthesized. Briefly, the amino group of p-aminophenol was first protected which then followed by O-arylation with 5-chloro-2-nitroaniline to provide compound d. Reduction of the nitro group of compound d and cyclization of the diamine group of compound e with oxalic acid afforded compound f which on deacetylation yeilded compound g. Then compound g was reacted with different acyl halides to afford the target compounds 1h-1p. Chemical structures of synthesized compounds were confirmed by 1H NMR and FT-IR analysis. All compounds were evaluated at 1, 10, 50 and 100 μM concentrations for their cytotoxicity against HeLa and MCF-7 cancer cell lines. Some of the compounds showed good cytotoxic activity, especially compounds 1i and 1k-1n with the IC50 values of 19, 16, 22, 18, and 16 μM against MCF-7 cell line and 20, 18, 25, 20, and 18 μM against HeLa cell line, respectively.

Novel VEGFR-2 kinase inhibitors identified by the back-to-front approach

We report a novel VEGFR-2 inhibitor, developed by the back-to-front approach. Docking experiments indicated that the 3-chloromethylphenylurea motif of the lead compound occupied the back pocket of VEGFR-2 kinase. An attempt was made to enhance the binding affinity of 1 by expanding the structure to access the front pocket using a triazole linker. A library of 1,4-(disubstituted)-1H-1,2,3-triazoles were screened in silico, and one compound (VH02) was identified with an IC50 against VEGFR-2 of 0.56μM. VH02 showed antiangiogenic effects, inhibiting tube formation in HUVEC cells (EA.hy926) at 0.3μM, 13 times lower than its cytotoxic dose. These enzymatic and cellular activities suggest that VH02 has potential as a lead for further optimization.