ABSTRACT
Chemical constituents from the ethanol extract of Radix Angelicae Pubescentis was isolated and purified through Diaion HP-20 macroporous, silica gel column chromatography, gel filtration over Sephadex LH-20 and preparative HPLC. Two new sesquiterpenoid derivatives were identified as angesesquid A (1) and angesesquid B (2), and their structures were determined. In vitro degeneration model of primary rat disc chondrocytes was used to evaluate the anti-inflammatory activity of these two compounds. The results showed that compounds 1 and 2 had no anti-proliferation effect. Both compounds inhibited the release of NO, but had no inhibitory activity for the release of PGE2. This finding implies that both of these two new sesquiterpenoids could moderately inhibit the inflammatory reaction to some extent.
ABSTRACT
Objective: To investigate the chemical constituents in the flower buds of Lonicera confusa. Methods: The chemical constituents were isolated by repeated silica gel chromatography, Sephadex LH-20, medium pressure column chromatography, and semi-preparative HPLC, and their structures were elucidated by spectroscopic analyses and comparison of NMR data with those reported in literature. Results: Ten compounds were isolated and identified to be chlorogenic acid (1), quercetin (2), luteolin (3), luteolin-3'-O-α-L-rhamnopyranoside (4), apigenin-7-O-α-L-rhamnopyranoside (5), trans-cinnamic acid (6), p-hydroxy benzaldehyde (7), gentisic acid-5-O-β-D-glucopyranoside (8), benzyl-β-D-glucoside (9), and abscisic acid (10). Conclusion: Compounds 4-10 are obtained from this plant for the first time.
ABSTRACT
The reaction conditions of baicalin hydrolyzed into baicalein by a kind of thermophilic and sugar-tolerant beta-glucosidase were studied in this paper. The beta-glucosidase could catalyze baicalin into baicalein well in the acetic acid-sodium acetate buffer. The optimal enzyme activity was at 85 degrees C and pH 5.5. The enzyme was stable at the temperature less than 85 degrees C and pH range of 5-7.5. The maximum reaction rate V. and michaelis constant K. were 0.41 mmol x L(-1) x min(-1) and 3.31 mmol x L(-1) respectively. Different metal ions had different effects on the activity of enzyme. Na+ existing in acetic acid-sodium acetate buffer had an activation effect on enzyme. The enzyme activity was enhanced by the concentrations of glucose below 0.6 mol x L(-1), and was gradually inhibited when monosaccharide concentration was over 0.6 mol x L(-1). When the monosaccharide concentration reached 1.2 mol x L(-1), the inhibition rate of enzyme activity was about 50%, which showed good glucose tolerance. The good reaction conditions through the experiment have been determined as follows, the substrate: enzyme dose was 1 g: 0.2 mL, acetic acid-sodium acetate buffer pH 5.5, reaction temperature 85 degrees C, reaction time 10 h, and the enzymatic hydrolyzation ratio could reach 97%.