Polyphenolic compositions and their bioactivity in the bulb of Lilium regale and L. davidii var. unicolor

To study the antioxidant and antibacterial activity of lily, using bulbs of Lilium regale and L. davidii var. unicolor as the experimental materials to investigate the contents of total polyphenol, flavone, flavanol and monomeric phenol of the bulb via colorimetry, high performance liquid chromatography and turbidimetry, and the antioxidant capacity and the antibacterial activity of that had been also stuied.The results demonstrated that there had a significant difference between the polyphenol contents in the bulbs of two Lilium species (p<0.05). The contents of total polyphenol, flavonoid, flavanol from L. regale were 2.07, 2.25 and 3.16 times higher than those of L. davidii var. unicolor, respectively. Fourteen monomeric phenolic compounds were identified from the two Lilium species, among them, the content of procyanidin B2 was the highest, reaching 37.60 mg·kg^-1 and 20.60 mg·kg^-1 in L. regale and L. davidii var. unicolor respectively, and the contents of which in the bulb of Lilium regale were 1.43 to 41.84 folds of those in L. davidii var. unicolor, except for the gallic acid content. Furthermore, the antioxidation and antibacterial activities of polyphenol extracts from Lilium regale were significantly 1.40~14.40 folds stronger than those from L. davidii var. unicolor (p<0.05). These findings suggested that polyphenolic extract of Lilium regale would possesse a great potential application prospect in the antioxidative food development and bacteriostatic pharmaceutical industry.