Discovery and SAR of Novel Disubstituted Quinazolines as Dual PI3Kalpha/mTOR Inhibitors Targeting Breast Cancer.

The dual PI3Kα/ m TOR inhibitors represent a promising molecularly targeted therapy for cancer. Here, we documented the discovery of new 2,4-disubstituted quinazoline analogs as potent dual PI3Kα/sm TOR inhibitors. Our structure based chemistry endeavor yielded six excellent compounds 9e, 9f, 9g, 9k, 9m, and 9o with single/double digit nanomolar IC50 values against both enzymes and acceptable aqueous solubility and stability to oxidative metabolism. One of those analogs, 9m, possessed a sulfonamide substituent, which has not been described for this chemical scaffold before. The short direct synthetic routes, structure-activity relationship, in vitro 2D cell culture viability assays against normal fibroblasts and 3 breast cancer cell lines, and in vitro 3D culture viability assay against MCF7 cells for this series are described.

Synthesis and Characterization of New Dihydronaphthalene Candidates as Potent Cytotoxic Agents against MCF-7 Human Cancer Cells.

In the present work, a new series of dihydronaphthalene derivatives were synthesized starting with 6-methoxy-1-tetralone 1, and the corresponding hydrazine derivative 2. Reaction of compound 2 with aryl isothiocyanates produced thiosemicarbazides 3a-d, which were reacted with ethyl chloroacetate to give thiazolidinone derivatives 4a-d. Pyrano thiazolecarbonitrile derivatives 5a-f were prepared by heating a mixture of compounds 4a or 4c, aryl aldehydes, and malononitrile utilizing distilled water in the presence of catalytic amount of potassium hydrogen phthalate. Also, treatment of 4a with DMF-DMA under solvent-free conditions gave enaminone derivative 6, which condensed with ethyl acetoacetate or acetylacetone or malononitrile or cyanothioacetamide to give compounds 7-10, respectively. Finally, reaction of the enaminone 6 with 2-aminoimidazol or 2-aminothiazol in the presence of glacial acetic acid produced derivatives 11 and 12, respectively. Cytotoxic evaluation of eleven compounds, against MCF-7 (human breast adenocarcinoma) cell lines, was estimated. Results revealed that five of the examined compounds 5a, 5d, 5e, 10, and 3d showed potent cytotoxic activities recording, IC50 values; 0.93 ± 0.02, 1.76 ± 0.04, 2.36 ± 0.06, 2.83 ± 0.07, and 3.73 ± 0.09 µM, respectively, which were more potent than the reference used (Saturosporin, IC506.08 ± 0.15 µM). The new products were also examined towards normal epithelial breast cells (MCF10A). All of them showed very good safety profile with different degrees and were safer than the reference drug used. Compound 5a was the most effective against MCF-7 cells and was less toxic than Saturosporin by about 18.45-folds towards MCF01A normal cells. All the new compounds were fully characterized by the different spectral and analytical tools. Herein, detailed syntheses, spectroscopic, and biological data are reported.

Design, synthesis and SAR of new-di-substituted pyridopyrimidines as ATP-competitive dual PI3Kα/mTOR inhibitors.

PI3Kα/mTOR ATP-competitive inhibitors are considered as one of the promising molecularly targeted cancer therapeutics. Based on lead compound A from the literature, two similar series of 2-substituted-4-morpholino-pyrido[3,2-d]pyrimidine and pyrido[2,3-d]pyrimidine analogs were designed and synthesized as PI3Kα/mTOR dual inhibitors. Interestingly, most of the series gave excellent inhibition for both enzymes with IC50 values ranging from single to double digit nM. Unlike many PI3Kα/mTOR dual inhibitors, our compounds displayed selectivity for PI3Kα. Based on its potent enzyme inhibitory activity, selectivity for PI3Kα and good therapeutic index in 2D cell culture viability assays, compound 4h was chosen to be evaluated in 3D culture for its IC50 against MCF7 breast cancer cells as well as for docking studies with both enzymes.