Potential cytotoxic and selective effect of new benzo[b]xanthenes against oral squamous cell carcinoma

The current work shows a new synthetic methodology to obtain 21 naphthoquinones that have been evaluated against oral cavity cancer. The compounds were obtained by a three-component reaction involving lawsone, dimedone and aromatic aldehydes catalyzed by lithium chloride under microwave irradiation to produce families of 1,4- and 1,2-naphthoquinones.

A clonogenic assay was performed on SCC9 cell line cultures with all compounds, revealing five very active compounds. In the 3,4,5-dimethylthiazol-2,5-diphenyltetrazolium bromide cell viability assay using three different cell lines (SCC9, SCC4 and SCC25), 8c had an average IC₅₀ of approximately 1.45 μM capable of reducing tumor cell viability, approximately 90-times higher than carboplatin.

Therefore, the xanthene-naphthoquinone derivatives show promising bioactivity for oral cavity cancer treatment.