Isolation of chemical ingredients from Aster ageratoides and their anticomplement and anti-inflammatory activities / 中草药

ABSTRACT

Objective To isolate and identify chemical ingredients with anti-complement activity from Aster ageratoides and investigate the key targets and anti-inflammatory activities of obtained compounds with good anti-complement activity. Methods Using silica gel column, sephadex LH-20 column, Medium Pressure Liquid Chromatography system, and Semi-preparative HPLC, chemical ingredients that displayed anti-complement activity were isolated. Their chemical structures were identified by 1H-NMR and 13C-NMR and their anti-complement activities and targets were investigated by erythrocyte hemolysis in vitro. In addition, using LPS-stimulated RAW264.7 cells, we investigated the anti-inflammatory activity of compound 2. Results A total of 14 compounds were obtained from A. ageratoides and identified as oleanolic acid (1), quercetin (2), kaempferol (3), 3,5,7,3’-tetrahydroxy- 4’-methoxyflavone (4), kaempferol-7-O-α-L-rhamnopyranoside (5), quercetin-3-O-β-D-glucopyranoside (6), kaempferol-3-O-α-L- rhamnoside (7), quercetin-3-O-α-L-rhamnoside (8), kaempferide-3-O-β-D-glucopyranoside (9), kaempferol-3-O-β-D- glucopyranoside (10), kaempferol-7-O-β-D-glucopyranoside (11), kaempferol-3-O-β-D-glucopyranoside-7-O-β-D-glucopyranoside (12), kaempferide-3-O-α-L-rhamnoside-(1→6)-β-D-glucopyranoside (13), and rutin (14). They all exhibited anti-complement activity to some certain degree and good structure-activity relationship. The targets of compounds 1 and 2 were C1q, C5, and C9 and C1q, C2, C5, and C9, respectively. The anti-inflammatory experiments indicated that compound 2 exhibited a significant biological activity, which significantly suppressed the release of NO, TNF-α, and IL-6 and expressions of iNOS and COX-2. Conclusion A total of 14 compounds were obtained and they all displayed anticomplement activity, of which compounds 1, 4, 6, 9, 12, and 13 are firstly discovered in A. ageratoides. Compound 2 exhibited a significant anti-inflammatory activity.