iridoids and flavone

To establish a method for analyzing solid phase extraction-high performance liquid chromatography-electrospray ionization tandem mass spectrometry (SPE-HPLC-ESI-MS(n)), in order to recognize and identify the main chemical constituents in Qinghuo Zhimai tablets.. The possible structures of the compounds were determined according to the structure information of compounds observed from molecular ion peaks and fragment ions in HPLC-ESI-MS(n) negative ion mode and by comparing with literature data or control samples.. Through the comparative analysis on Qinghuo Zhimai Tablets and components of its formula, 39 chemical constituents were identified, including 7 caffeoylquinic acids, 7 iridoids, 6 diterpenoid lactones, 5 homoisoflavonoids, 13 steroidal saponins and 1 flavone glycoside.. This study provides a simple and rapid method for identifying chemical components in Qinghuo Zhimai tablets.

Topics: Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Flavones; Glycosides; Iridoids; Lactones; Medicine, Chinese Traditional; Molecular Structure; Quinic Acid; Saponins; Solid Phase Extraction; Spectrometry, Mass, Electrospray Ionization; Tablets; Tandem Mass Spectrometry

Several epidemiological and experimental studies have associated the intake of antioxidants, which are abundant in the Mediterranean diet, with a low incidence of cardiovascular disease. One possible mechanism of this action is the oxidative protection in low density lipoproteins (LDL). The aim of our study was to compare the antioxidative activity of diverse phenolic compounds present in virgin olive oil on these lipoproteins.. LDL was isolated from blood plasma of healthy volunteers by sequential ultracentrifugation. This was followed by oxidation with CuC12 in the presence of different concentrations of phenolic compounds and virgin olive oil extract. Production of conjugated dienes was determined by the continuous monitoring of increased absorbency at 234 nm as an indicator of LDL oxidation.. Virgin olive oil extract prolonged the latency phase and significantly lowered the progression rate (p < 0.05) at low concentrations (2 g/ml). This antioxidative effect was also observed with low concentrations (2 M) of caffeic acid and oleuropein (p < 0.05). However, it was necessary to increase the concentration of flavone up to 50 times to observe a similar effect (p < 0.05).. Both virgin olive oil extract enriched in phenolic compounds and phenolic compounds present in olive oil (caffeic acid and oleuropein) are potent antioxidants at very low concentrations. Thus, the beneficial effects of a Mediterranean diet may be partly due to the protective action of these compounds.

Topics: Antioxidants; Caffeic Acids; Diet, Mediterranean; Dietary Fats, Unsaturated; Flavones; Flavonoids; Humans; In Vitro Techniques; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Lipoproteins, LDL; Olive Oil; Oxidation-Reduction; Phenols; Plant Oils; Pyrans; Vasodilator Agents

A survey of the flavonoid glycosides of selected taxa in the genus Veronica yielded two new acylated 5,6,7,3',4'-pentahydroxyflavone (6-hydroxyluteolin) glycosides and two unusual allose-containing acylated 5,7,8,4'-tetrahydroxyflavone (isoscutellarein) glycosides. The new compounds were isolated from V. liwanensis and V. longifolia and identified using NMR spectroscopy as 6-hydroxyluteolin 4'-methyl ether 7-O-alpha-rhamnopyranosyl(1"'-->2")[6"-O-acetyl-beta-glucopyranoside] and 6-hydroxyluteolin 7-O-(6"-O-(E)-caffeoyl)-beta-glucopyranoside, respectively. Isoscutellarein 7-O-(6"'-O-acetyl)-beta-allopyranosyl(1"'-->2")-beta-glucopyranoside was obtained from both V. intercedens and V. orientalis and its 4'-methyl ether from V. orientalis only. Complete 1H and 13C NMR spectral assignments are presented for both isoscutellarein glycosides. Two iridoid glucosides new to the genus Veronica (melittoside and globularifolin) were also isolated from V. intercedens.

Topics: Acylation; Flavones; Flavonoids; Glycosides; Iridoids; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Veronica