A Novel Bihomoflavanonol with an Unprecedented Skeleton from Pteridium aquilinum

ObjectiveTo seek the flavonoids with the unique structure and to investigate the chemical ingredients in the flavonoid-rich plant—Pteridium aquilinum.MethodsThe 80% EthOH extract from the degreased powder of P. aquilinum was partitioned by petroleum ether, CHCl3, EtOAc, n-butanol, and water, respectively. The EtOAc fraction was sequentially subjected to silica gel column, repeated Sephadex LH-20 column, and preparative TLC to give a new compound. The antitumor activity of the novel flavonoid was primarily evaluated by MTT.ResultsCompound 1, a biflavonoid with the unique structure named as pteridium III with an unprecedented bihomoflavanonol skeleton, was isolated from P. aquilinum. Compound 1 showed the in vitro antitumor activity against lung cancer cell NCI-H46, melanoma cell A375, and glioma cell U-7MG corresponding to the IC50 values of 22.9, 106.7, and 1540.5 μmol/L, respectively. No inhibition on gastric carcinoma SGC-7901 and prostatic carcinoma PC-3 was observed in the experiment.ConclusionA rare bihomoflavononol derivative, pteridium III, is obtained from the plant, which could enrich our knowedge on the chemical structures of flavonoids and bioactive constituents in P. aquilinum.