Synthesis of Novel Xanthone Analogues and Their Growth Inhibitory Activity Against Human Lung Cancer A549 Cells

Xanthones demonstrated an array of pharmacological activities via non-covalent DNA interaction and have been widely utilized in new drug research. The introduction of the polar 1,2,3-triazole ring located at the C3-position of xanthone has not been reported thus far.

In the present study, a series of xanthone derivatives were designed, synthesized, and characterized through ¹H NMR, ¹³C NMR, and MS. The methyl thiazolyl tetrazolium method was used to evaluate the cytotoxic activity of compounds. Furthermore, the structure-activity relationship and the potential mechanism of target compounds were investigated.

The IC₅₀ showed that the inhibitory activity of 18 target compounds was higher than that of the original xanthone intermediate 4. In particular, compound 1j was the most active agent against A549 cancer cells (IC₅₀ = 32.4 ± 2.2 μM). Moreover, apoptosis analysis indicated different contributions of early/late apoptosis to cell death for compounds 1h and 1j. The results of Western blotting analysis showed that compound 1j significantly increased the expression of caspase 3, Bax, and c-Jun N-terminal kinase, and regulated p53 to a better healthy state in cancer cells.

We synthesized several derivatives of xanthone and evaluated their cytotoxicity. The evidence suggested that compound 1j possessed greater anticancer potential for further evaluations.