Preparative separation of flavonoids in Adinandra nitida leaves by high-speed counter-current chromatography and their effects on human epidermal carcinoma cancer cells

Preparative separation of camellianins A and B in Adinandra nitida leaves, which is a flavonoid-rich plant source with great practical prospects, was conducted by high-speed counter-current chromatography (HSCCC) with a solvent system composed of ethyl acetate–ethanol–water (5:1:5, v/v). Apigenin (their aglycone) was prepared by hydrolysing a water extract and recrystallising. The purity and identity of these flavonoids was confirmed by HPLC-ESI/MS, and 1H and 13C NMR. These flavones were used in cultures of the A431 cell line. Their inhibitory effect was evaluated by using the MTT assay. The results showed that three flavones could significantly inhibit the growth of human epidermal carcinoma cancer cells in a concentration-dependent manner. After 48 h of treatment, IC50 values of camellianin A, camellianin B and apigenin against A431 tumour cells were 9.09 μM, 12.5 μM, 21.0 μM, respectively.