[Chemical constituents from Xanthii Fructus]

This study was carried out to investigate the chemical constituents from Xanthii Fructus(the fruits of Xanthium sibiricum). The compounds were separated and purified by silica gel column chromatography, Sephadex LH-20 and ODS chromatography and semi-preparative HPLC. Base on HR-ESI-MS, NMR and other spectral data, their structures were identified. The anti-inflammatory activity of the isolated compounds was evaluated by lipopolysaccharide(LPS)-induced macrophage RAW264.7 as a screening model. A total of twenty-one compounds were isolated from the EtOAc fraction of 95% ethanol extract and identified as uracil(1), thymine(2), uridine(3), indole-3-carbaldehyde(4), indole-3-carboxylic acid(5), 2'-O-methyluridine(6), guanosine(7), 2,4(1H,3H)-quinazolinedione(8), 3-hydroxy-3-(2-hydroxyethyl)indolin-2-one(9), nicotinamide(10), N-acetyl-L-phenylalaninol(11), heliolactam(12), terresoxazine(13), caudatin(14), qingyangshengenin(15), caudatin-3-O-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside(16), caudatin-3-O-β-D-cymaropyranosyl-(1→4)-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside(17), caudatin-3-O-α-L-cymaropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-α-L-cymaropyranosyl-(1→4)-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranoside(18), qinyangshengenin-3-O-β-D-oleandropyranosyl-(1→4)-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranoside(19), qinyangshengenin-3-O-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-digitoxopyranoside(20), rostratamine-3-O-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside(21). Compounds 5-21 are obtained from genus Xanthium for the first time. Compounds 12 and 13 indirectly exhibited anti-inflammatory activity by suppressing LPS-induced NO production in RAW264.7 cells with IC_(50) values of(15.45±0.56) and(20.14±0.78) μmol·L~(-1), respectively.

Keywords: Compositae; Xanthii Fructus(fruits of Xanthium sibiricum); heliolactam; nicotinamide; terresoxazine.