Hit discovery of novel 2-phenyl-substituted 4-amino-6,7-dihydro-5H-cyclopenta[d]pyrimidines as potential anti-glioblastoma therapeutics: Design, synthesis, biological evaluation, and computational screening.

Glioblastoma multiforme (GBM) is a highly-aggressive, dreadful disease with poor prognosis and disappointing clinical success. There is an unmet medical need of molecularly-targeted therapeutics for GBM treatment. In the present work, a series of novel 2-phenyl-substituted 4-amino-6,7-dihydro-5H-cyclopenta[d]pyrimidines was designed, synthesized, purified, characterized, and evaluated for cytotoxicity against glioblastoma cell line U87-MG. The design process (virtual library enumeration around the core, physicochemical and molecular property prediction/calculation of the designs, filtering the undesirable ones, and the diversity analyses of the lead-like designs), was carefully curated so as to obtain a set of structurally-diverse, novel molecules (total 20), with a particular focus on the relatively unexplored core structure, 6,7-dihydro-5H-cyclopenta[d]pyrimidine. The preliminary screening was done using MTT assay at 10 and 100 µM concentrations of the title compounds F1 -F20 and positive control cisplatin, which yielded six hits (% inhibition at 10 µM: ~50%)-F2 , F3 , F5 , F7 , F15 , and F20 , which were taken up for IC50 determination. The top hits F2 and F7 (IC50 < 10 µM) were further used for computational studies such as target prediction, followed by their molecular docking in the binding sites of the top-3 predicted targets (epidermal growth factor receptor kinase domain, cyclin-dependent kinase 2 [CDK2]) /cyclin E, and anaplastic lymphoma kinase [ALK]). The docking pose analyses revealed interesting trends. The relatively planar core structure, presence of favorable hinge-binding substructures, basic groups, all added up, and culminated in appreciable cytotoxicity against GBM cell line.

Synthesis and Photophysical Study of [60]Fullerene-Maleimide Dyads.

Novel [60]fullerene-maleimide dyads were synthesized by covalent linking of maleimide fluorophore to the [60]fullerene (C60) via Bingel reaction. The dyads were well characterized and studied for their absorption and emission properties. The fluorescence quenching of maleimide moiety by C60 was observed, indicating the intramolecular energy transfer from maleimide fluorophore to C60 moiety.

Cyclopentyl-pyrimidine based analogues as novel and potent IGF-1R inhibitor.

A series of novel 2-amino-4-pyrazolecyclopentylpyrimidines have been prepared and evaluated as IGF-1R tyrosin kinase inhibitors. The in vitro activity was found to depend strongly on the substitution pattern in the 2- amino ring, 4-pyrazolo moieties and size of fused saturated ring with the central pyrimidine core. A stepwise optimization by combination of active fragments led to discovery of compound 6f and 6k, two structures with IGF-1R IC50 of 20 nM and 10 nM, respectively. 6f was further profiled for its anti cancer activity across various cell lines and pharmacokinetic studies in Sprague Dawley rats.

Synthesis and biological evaluation of novel N-aryl maleimide derivatives clubbed with α-hydroxyphosphonates.

A series of novel molecules 5a-g containing N-aryl maleimide and α-hydroxyphosphonate moieties were synthesized. A distinct approach for high-yielding synthesis of α-hydroxyphosphonates has been discovered using various catalyst and solvents. The structures of the synthesized compounds were elucidated by IR, NMR, MS and CHN analysis. All the synthesized compounds were tested for qualitative (Zone of inhibition) and quantitative (MIC) antimicrobial activities against two pathogenic bacteria such as Bacillus subtilis (NCIM 2250) and Escherichia coli (ATCC 25922) and four pathogenic fungi such as Candida albicans (MTCC 277), Candida tropicalis (MTCC184), Aspergillus niger (MCIM 545) and Aspergillus clavatus (MTCC 132). The investigation of antimicrobial screening data revealed that most of the tested compounds are moderate to good microbial inhibitors.