Development of Pyranoquinoline based Compounds and their Apoptosis: Triggering Mechanisms in Human Cancer Cells

The current work emphasises a direct, synthetically efficient and operationally convenient approach of a series of novel fused pyranoquinoline derivatives 4(af) via the intramolecular cyclisation of the corresponding styryl intermediate 3(a-f). The novel pyranoquinolines were structurally characterized and evaluated for cytotoxic activity against human cancer cells. The structures of these compounds were established on the basis of spectral data. The anticancer activity of the synthesized compounds 4(a-f) was investigated against human breast cancer cells (MCF-7) and lung cancer cells (A-549) using MTT colorimetric assay. The compounds 4(a-f) exhibited dose-dependent cytotoxicity against the cell lines (MCF-7 and A-549). The compounds 4(a-f) were found to trigger apoptogenesis in the selected cancer cells compared with that of the standard drug doxorubicin, a well-known anticancer drug, using MTT colorimetric assay. Compounds 4e and 4f showed the most potent activity against the human breast tumor cells (MCF-7) while compounds 4c and 4e exhibited the most potent activity against the human lung carcinoma cells (A-549). Overall, this work highlights the possibility to employ a convenient, rapid and specific synthesis of pyranoquinoline analogues without any side products, as well as in the development of novel chemotherapeutic agents with reduced systemic toxicity. The chemical structures of the synthesised pyranoquinoline and the results pertaining to the structure-activity correlation are discussed in this study.