Synthesis and insecticidal activities of 1,8-naphthyridine derivatives

Pyrazole derivatives of pyridine and naphthyridine as proapoptotic agents in cervical and breast cancer cells

Cancer is one of the leading causes of death worldwide. The increasing prevalence and resistance to chemotherapy is responsible for driving the search of novel molecules to combat this disease. In search of novel compounds with pro-apoptotic potential, pyrazolo-pyridine and pyrazolo-naphthyridine derivatives were investigated against cervical cancer (HeLa) and breast cancer (MCF-7) cells. The anti-proliferative activity was determined through the MTT assay. Potent compounds were then analyzed for their cytotoxic and apoptotic activity through a lactate dehydrogenase assay and fluorescence microscopy after propidium iodide and DAPI staining. Flow cytometry was used to determine cell cycle arrest in treated cells and pro-apoptotic effect was verified through measurement of mitochondrial membrane potential and activation of caspases. Compounds 5j and 5k were found to be most active against HeLa and MCF-7 cells, respectively. G0/G1 cell cycle arrest was observed in treated cancer cells. Morphological features of apoptosis were also confirmed, and an increased oxidative stress indicated the involvement of reactive oxygen species in apoptosis. The compound-DNA interaction studies demonstrated an intercalative mode of binding and the comet assay confirmed the DNA damaging effects. Finally, potent compounds demonstrated a decrease in mitochondrial membrane potential and increased levels of activated caspase-9 and -3/7 confirmed the induction of apoptosis in treated HeLa and MCF-7 cells. The present work concludes that the active compounds 5j and 5k may be used as lead candidates for the development of lead drug molecules against cervical and breast cancer.

Insecticidal activity of twin compounds from podophyllotoxin and cytisine

To explore natural-product-based insecticide candidates, and high value-added application of natural plants in agriculture, a series of twin compounds were prepared from two natural products podophyllotoxin and cytisine, which are isolated from the plants Podophyllum hexandrum and Thermopsis lanceolata, respectively. Compounds IIa (X = Cl, Y = R¹ = R² = H), IIIc (X = Y = R¹ = R² = Cl) and IVd (X = R¹ = R² = Br, Y = H) exhibited >2-fold potent insecticidal activity of podophyllotoxin against armyworm with FMRs greater than 60%. SARs were also observed. It is noteworthy that the idea of twin insecticides was addressed for the first time. We hope this idea will be conducive to design new twin insecticidal agents, and lay the foundation for future high value-added application of the plants P. hexandrum and T. lanceolata as potentially botanical pesticides in agriculture.