Phenolic profiles and antioxidant capacities of crude extracts and subsequent fractions from <i>Potentilla fruticosa</i> L. leaves

<p>This work aimed to further investigate the phenolic profiles and antioxidant capacities of the crude extracts and the subsequent fractions of <i>Potentilla fruticosa</i> leaves. Result showed that <i>P. fruticosa</i> leaves contained high amounts for hyperoside, ellagic acid and (+)-catechin contents, and the highest amount being registered for hyperoside (17.67 mg g⁻¹). Nine sub-fractions were obtained after column chromatographic separation. EF-3, EF-4, EF-5 and BF-2 presented higher values for their total phenolic or flavonoid, (+)-catechin, ellagic acid and hyperoside content. Besides, EF-3, EF-4, BF-2 and BF-3 showed significant <i>in vitro</i> antioxidant capacities and protective effects on <i>Escherichia coli</i> under peroxide stress. The correlation between chromatograms and antioxidant activity showed that (+)-catechin, ellagic acid and hyperoside may play crucial roles in the antioxidant capacities of <i>P. fruticosa</i> and could be used as chemical markers for its quality assessment. Moreover, this is the first time <i>P. fruticosa</i> leaves have been systematically studied.</p

Efficient quantification of the phenolic profiles of <i>Zanthoxylum bungeanum</i> leaves and correlation between chromatographic fingerprint and antioxidant activity

<p>Sixteen subsequent fractions were prepared from the ethyl acetate fraction of <i>Zanthoxylum bungeanum</i> leaves after bio-guided chromatographic separation. The HPLC profiles and antioxidant activity of the various fractions indicated that the content of eight phenolic compounds (chlorogenic acid, epicatechin, rutin, hyperoside, trifolin, quercitrin, afzelin and quercetin) and antioxidant activity vary significantly, and high concentrations of a combination of eight phenolic compounds would result in an increase of the antioxidant activity. These results suggested that the eight compounds could be used as chemical markers for quality assessment of <i>Z. bungeanum</i> leaves. Correlation between chromatographic fingerprint and antioxidant activity of the fractions showed that quercitrin and hyperoside play crucial roles in the antioxidant activity, and they can be seen as the milestone for quality control. The findings also suggested that five obtained fractions (E-3-3, E-2-4, E-7, E-5 and E-4) could become useful supplements for functional food ingredients and health-related products.</p