An Efficient Method for the Isolation of Toxins from Pteridium aquilinum and Evaluation of Ptaquiloside Against Cancer and Non-cancer Cells

The common fern, bracken (Pteridium aquilinum), is well known for its toxic effects on livestock due principally to the carcinogenic constituent ptaquiloside ( 1), although other toxins are present including the cyanogenic glycoside, prunasin ( 2). Here, we report an improved and relatively “green” process for the isolation of 1 and 2 from fresh bracken fronds and the evaluation of 1 for cytotoxicity against several cancer cell lines. The results indicate that 1 displays selective toxicity against cancer cells relative to noncancer retinal epithelial cells, and the improved method for the isolation of 1 is expected to facilitate further exploration of its pharmacological properties.