Synthesis and biological evaluation of nitroxide labeled pyrimidines as Aurora kinase inhibitors.

To find novel effective Aurora kinases inhibitors, a series of structurally interesting nitroxide labeled pyrimidines were synthesized and evaluated their anti-proliferative and Aurora kinases inhibitory activities. Among them, butyl 2-(3-((5-fluoro-2-((4-((1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)carbamoyl) phenyl) amino)pyrimidin-4-yl)amino)-1H-pyrazol-5-yl)acetate (22) possessed the most potent anti-proliferative effects against four carcinoma cell lines with IC50 values in range of 0.89-11.41 µM, and kinases inhibition against Aurora A and B with the IC50 values were 9.3 and 2.8 nM, respectively. Furthermore, compound 22 blocked the phosphorylation of Aurora A (T288), Aurora B (Thr232) and HisH3, decreased the expression of proteins TPX2, Eg5 and Bora, as well as disrupted the mitotic spindle formation in HeLa cells. Molecular docking studies indicated that compound 22 well interact with both Aurora A and B. The results showed that compound 22 is a potential anticancer agent as promising pan-Aurora kinase inhibitor.

Synthesis of hybrid 4-deoxypodophyllotoxin-5-fluorouracil compounds that inhibit cellular migration and induce cell cycle arrest.

A series of deoxypodophyllotoxin-5-fluorouracil hybrid compounds were synthesized, and their cytotoxic activity was evaluated using four human cancer cell lines (HeLa, A549, HCT-8, and HepG2) and the human normal cell line WI-38. The synthesized compounds exhibited greater cytotoxic activity in tumor cells and reduced toxicity in the normal cell line compared with the anticancer drug VP-16 and 5-FU. Additionally, the most potent of these compounds-4'-O-demethyl-4-deoxypodophyllotoxin-4'-yl 4-((6-(2-(5-fluorouracil-yl) acetamido) hexyl) amino)-4-oxobutanoate (compound 22)-induced cell-cycle arrest in the G2/M phase by regulating levels of cdc2, cyclinB1, and p-cdc2 in A549 cells. Furthermore, compound 22 may inhibited the migration of A549 cells via down-regulation of MMP-9 and up-regulation of TIMP-1.

Conjugates of podophyllotoxin and norcantharidin as dual inhibitors of topoisomeraseâ ¡ and protein phosphatase 2A.

A series of novel conjugates of podophyllotoxin and norcantharidin was designed using association strategy, and synthesized by coupling 4'-demethylepipodophyllotoxin with N-amino acid norcantharimides, and their cytotoxicitiy was evaluated against four human tumor cell lines (A-549, HepG2, HeLa and HCT-8) and normal human diploid fibroblast line WI-38. These compounds exhibited potent cytotoxic effects on tumor cell lines, whereas it was less toxic to WI-38 cells than anticancer drug VP-16 or its parent compound norcantharidin. Furthermore, conjugates 7a, 7c, 7f, 7j, 7k and 7l displayed excellent PP2A inhibition activity with IC50 values of 0.49-9.52 µM. The most potent compound 7l also exhibited topoisomeraseⅡinhibition activity. In addition, compound 7l induced cell-cycle arrest in the G2/M phase in HepG2 by regulating levels of cyclinB1 and cdc2.