Bioactive phenols as potential neuroinflammation inhibitors from the leaves of Xanthoceras sorbifolia Bunge

Xanthoceras sorbifolia Bunge is a medicinal plant and also a valuable cash crop used for production of edible oil and biofuels in China. In our previous research, systematical phytochemical and bioactive profiles of different parts from X. sorbifolia have been obtained. Here we describe the effective phenols from the leaves of X. sorbifolia, which could function as natural neuroinflammation inhibitors. As a result, 23 compounds were characterized as the phenols from the leaves of X. sorbifolia by means of chromatographical methods and spectroscopic analysis. Among them, flavonoids quercetin3-O-β-d-glucopyarnoside (IC50 13.39 ± 1.27 μM), catechin (IC50 9.52 ± 2.18 μM), and phenylpropanoids syringaresinol-4-O-β-d-glucopyranoside (IC50 3.08 ± 1.77 μM), 4-O-β-d-glucopyranosyl-trans-p-coumaric acid (IC50 9.08 ± 1.23 μM) exhibited much stronger inhibiting effect on NO production than that of the positive control minocycline (IC50 37.04 ± 2.09 μM) in LPS-induced BV2 cells.