Showing papers on "Isovitexin published in 2006"

Flavone c-glycosides and cucurbitacin glycosides from citrullus colocynthis

Abstract: Citrullus colocynthis (L.) Schrad. (Cucurbitaceae) is an Iranian medicinal plant that has traditionally been used as an abortifacient and to treat constipation, oedema, bacterial infections, cancer and diabetes. As part of our on-going studies on Iranian medicinal plants, thorough phytochemical investigation was carried out on this plant. The reversed-phase preparative HPLC was employed to isolate compounds from the butanol fraction of the hydro-methanolic (70%) extract of the fruits of the locally grown C. colocynthis. Structures of the isolated compounds [1-5] were elucidated by spectroscopic means. The antioxidant property of the flavonoids 1-3 was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Three flavone glucosides, isosaponarin [1], isovitexin [2] and isoorientin 3’-O-methyl ether [3] and two cucurbitacin glucosides, 2-O-β-D-glucopyranosylcucurbitacin I [4) and 2-O-β-Dglucopyranosylcucurbitacin L [5] were isolated and identified. Flavonoids 1-3 showed significant antioxidant properties. Since reactive oxygen species are important contributors to tissue injury, inflammation, cancer and many other ailments, the antioxidant properties of 1-3 probably contribute, at least to some extent, to the pharmacological and traditional medicinal uses of the C. colosynthis.

Antioxidant properties of flavone C-glycosides from atractylodes japonica leaves in human low-density lipoprotein oxidation

Abstract: Three antioxidant flavone C-glucosides, isoorientin, vitexin, and isovitexin, were identified for the 1st time from Atractylodes japonica leaves by an activity-guided fractionation with various analytical techniques including column chromatography, high-performance liquid chromatography (HPLC), fast atom bombardment mass spectrometry (FAB-MS), and nuclear magnetic resonance (NMR). Hydroxyl and superoxide anion radicals scavenging activities of these compounds were examined using electron spin resonance (ESR). Inhibitory activities of these compounds on human low-density lipoprotein (LDL) oxidation were evaluated by malondialdehyde (MDA) and thiobarbituric acid-reactive substances (TBARS), both representing intermediates of lipid peroxidation. These flavone C-glucosides displayed about 50% of scavenging activity against hydroxyl radicals at the concentrations below 10 μM. The superoxide dismutase (SOD)-equivalent activities of isoorientin, vitexin, and isovitexin at 1 mM were 31.37, 2.71, and 2.63 unit/mL, respectively. Isoorientin at 1 μM exhibited over 60% inhibition of MDA formed during copper-mediated human LDL oxidation. Amounts of free MDA in LDL treated with isoorientin, vitexin, isovitexin, and control were 20.06, 40.73, 34.08, and 48.03 nM/mg protein, respectively. These compounds also prolonged the lag phase time of the conjugated diene formation. There was a positive correlation between the free radical scavenging activities and the inhibitory effects on the LDL oxidation of these compounds. These results suggest that the flavone C-glucosides isolated from the leaves of A japonica possess beneficial antioxidant properties against free radicals as well as LDL oxidation.

Phytochemical study and antiulcerogenic activity of Syngonanthus bisulcatus (Eriocaulaceae)

Abstract: From the ethanol extract of the capitula and scapes of Syngonanthus bisulcatus (Koern) Ruhland the flavonoids 5-hydroxy-7,4'-dimethoxy-6-C-beta-D-glucopyranosylflavone, isovitexin (5,7,4'-trihydroxy-6-C-beta-D-glucopyranosylflavone), luteolin (5,7,3',4'-tetrahydroxyflavone), lutonarin (5,3',4'-trihydroxy-6-C-7-O-beta-D-glucopyranosylflavone) and 5,6,3',4'-tetrahydroxy-7-O-beta-D-glucopyrade were isolated. The structure of the compounds were characterized by spectroscopic methods, mainly 1D and 2D NMR experiments, as well as ESMS spectrometry. In addition we examined the effect of the ethanol extract of capitulae and scapes in the ulcer model ethanol/HCl-induced gastric mucosal lesions.

Secondary Metabolites from Asphodelus aestivus

Abstract: Together with ten well known compds., the quinic acid deriv. chlorogenic acid, the nucleoside adenosine, two amino acids, tryptophan and phenylalanine, the anthraquinone derivs., aloemodin, aloemodin acetate and chyrosphanol 1-O-gentiobioside, the flavon C-glycosides, isovitexin, isoorientin and isoorientin 4'-O-beta -glucopyranoside, as well as two new acylated isoorientin derivs., 6''-O-(malonyl)-isoorientin and 6''-O-[(S)-3-hydroxy-3-methylglutaroyl]-isoorientin, were isolated from the water sol. part of the methanolic ext. of the fresh leaves of Asphodelus aestivus. All compds. were structurally identified by spectroscopic methods, including UV, MS, and NMR (1D and 2D) spectroscopy. Among the compds. isolated, chlorogenic acid and isoorientin were found to be the main compds. of the methanolic ext.

Studies on chemical constituents of Patrinia villosa

Abstract: OBJECTIVE To investigate the chemical constituents of Patrinia villosa. METHOD The chemical constituents were isolated by silica gel column chromatography and semi-preparative high-performance liquid chromatography, and identified by physicochemical properties and spectral analysis (MS, 1H-NMR and 13C-NMR). RESULT Seven compounds were isolated from ethyl acetate and n-butanol extract and identified as: 5-hydroxyl-7, 3', 4'-trimethoxy flavone (I), 5-hydroxyl-7, 4'-dimethoxy flavone (II), luteolin (III), quercetin (IV), isoorientin (V), isovitexin (VI) and 8-C glucosylprunetin (VII). CONCLUSION Compounds I , II, III, V, VI and VIII were obtained from the plant of genus Patrinia for the first time, compound IV was separated from P. villosa for the first time.

C-glycosylflavones from Stellaria media

Abstract: AIM: To isolate the chemical constituents from the aerial parts of Stellaria media (L.) Cyr.. METHODS: The compounds were isolated through column chromatography and recrystallization. The structures were elucidated by means of physio-chemical data and spectroscopy. RESULT: Fourteen C-Glycosylflavones were isolated from this plant, and their structures were elucidated as apigenin (1), vicenin (6, 8-di-C-β-D-glucopyranosyl apigenin) (2), 8-C-β-D-galactopyranosyl isovitexin(6-C-β-D-glucopyranosyl-8-C-β-D-galactopyranosyl apigenin) (3), 6-C-β-D-galactopyranosyl vitexin (6-C-β-D-galactopyranosyl-8-C-β-D-glucopyranosyl apigenin) (4), 6, 8-di-C-α-L-arabinopyranosyl apigenin (5), schaftoside (6-C-β-D-glucopyranosyl-8-C-α-L-arabinosyl apigenin) (6), isoschaftoside (6-C-α-L -arabinosyl-8-C-β-D-glucopyranosyl apigenin) (7), 6-C-β-D-galactopyranosyl-8-C-α-L-arabinosyl apigenin (8), 8-C-β-D-galactosyl apigenin (9), vitexin (8-C-β-D-glucopyranosyl apigenin) (10), isovitexin (6-C-β-D-glucopyranosyl apigenin) (11), tricetin 6, 8-di-C-β-D-glucopyranosyl (12), tricetin 6-C-α-L-arabinosyl-8-C-β-D-glucopyranosyl (13) and 7-O-β-D-glucopyranosyl-6-C-β-D-6”-acetyl-glucopyranosyl apigenin (14). CONCLUSIONS: Compounds 3~8 and compounds 12 and 13 have been found in the plant for the first time, and compound 14 is a new C-glycosylflavone.

Sequestration and metabolism of host-plant flavonoids by the Pale Grass Blue, Pseudozizeeria maha (Lepidoptera : Lycaenidae)

Abstract: Flavonoids in the eggs, larvae, pupae and adult butterflies of Pseudozizeeria maha were identified and quantified. Isovitexin (apigenin 6-C-glucoside) was the dominant flavonoid detected in pupae and imagines, whereas saponarin (isovitexin 7-O-glucoside) was the dominant flavonoid in larvae. Saponarin, biotransformed from isovitexin by the larvae, was found to be reconverted into isovitexin at the pupal stages. The total amounts of accumulated flavonoids differed between sexes, particularly in adults where the bodies of females had a much higher flavonoid concentration than that of the males. These flavonoids were also detected in the eggs. These results indicate the possibility that flavonoids are utilized in not only wing coloration but also as a chemical defense compound against natural threats.

Flavonoid and Flavone C-Glycosides from Dregea volubilis:

Abstract: A new acylated flavone C-glycoside, dregeanin (1) was isolated from the flowers of Dregea volubilis, together with vicenin-2, vitexin, isovitexin, isoorientin, rutin, quercetin, luteolin and apigen...

Glycosides of Lomatogonium rotatum

Abstract: The extract extracted by ethanol from whole Lomatogonium rotatum plants was extracted with n-butyl alcohol and seven water-soluble components were isolated form the extract extracted with n-butyl alcohol was by silica column chromatorgraphy and Sephadex LH-20 and RP-18 isolations and purificationsThe components were identified by ~1H NMR and ~(13)C NMR as isoorientin,mangiferin,swertipunicoside,swertianolin,isovitexin,sweertisin and 7-O-[α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl]-1,8-dihydroxy-3-methoxyxanthoneAll the compounds but isoorientin were obtained from the plant for the first time

Total Phenolic Content and Antioxidant Activity of Flavonoids Isolated From Leaves of Selected Citrus Species

Abstract: Water and 80% methanol crude extracts from the leaves of Citrus aurantifolia, C. hystrix, C. grandis, and Citrofortunella microcarpa were investigated for their total phenolic content and its relationship with total antioxidant activity. The total phenolic content was determined using a Folin-Ciocalteu reagent whereas determination of total antioxidant activity was carried out using a β-carotene bleaching method. Among the citrus leaves extracts, the highest total phenolic content was found from the water extract of Citrofortunella microcarpa whereas the water extract of C. maxima and Citrofortunella microcarpa gave the highest total antioxidant activity and was comparable with the antioxidant activity of marker BHT. However, no clear correlation was found between the total phenolic content and the total antioxidant activity of citrus leaves in both crude extract. Eleven flavonoid components were isolated and identified from the 80% methanolic extract of the leaves of Citrus aurantifolia, C. hystrix, C. grandis and Citrofortunella microcarpa. The isolation and purification of all flavonoid components were carried out using standard paper chromatography technique. The isolated components were identified basis of their spectral analysis with shift reagents, Rf values, colour reactions under UV and UV+NH3, hydrolysis with acid and co-chromatogram with standard markers. The successfully isolated flavonoids were consisted from the group of flavone, flavone C-glycoside and flavonol. The methylated and glycosylated flavonoids were also isolated. The antioxidant capacity of isolated flavonoids was measured by two assays; a β-carotene bleaching method and a DPPH scavenging method. Statistical analysis showed that the total antioxidant and free radical scavenging activity of the isolated flavonoids was significantly low compared to the markers. Among the isolated flavonoids, results showed that at the 60th minute, quercetin 4’-O-glucoside exhibited the highest total antioxidant activity. Quercetin 4’-O-glucoside also showed a significantly higher free radical scavenging activity in DPPH scavenging method than the other isolated flavonoids. The lowest activities in both assays were exhibited by vitexin 7-O-arabinoside and isovitexin.