Isovitexin

About: Isovitexin is a research topic. Over the lifetime, 526 publications have been published within this topic receiving 11525 citations. The topic is also known as: 6-Glucosylapigenin & Isovitexin.

Differential Regulation of Two Genes Controlling the Biosynthesis of Isovitexin 7-O-Galactoside in Silene Plants

Abstract: Abstract The expression of the allelic isovitexin 7-O-glycosylation genes gG (transfer of glucose) and gX (transfer of xylose) was studied in cotyledons, rosette leaves, stem leaves and petals of Silene plants. These studies revealed that gG is expressed in all ontogenetic stages, whereas its allele gX is only expressed in the petals. In the vegetative parts of gX individuals 7-O -xylosylation is replaced by 7-O-galactosylation. The possibility that gX encodes an enzyme activity that catalyzes different reactions in the petals and the vegetative parts resulting in the accumulation of the 7-O-xyloside and the 7-O-galactoside respectively, has been disproved. It is shown that there are two different enzymes catalyzing the biosynthesis of isovitexin 7-O-galactoside. These 7-O -galactosyl-transferase activities differ with respect to heat inactivation, pH optimum , flavone acceptor specificity and Michaelis-Menten enzyme kinetic parameters. The genes controlling these enzyme activities are regulated differentially, with gene O7g (described previously by Steyns et al. [11]), expressed in the cotyledons and the rosette leaves and Xgal in the stem leaves and petals.

Identification of xanthones and new arabinosides of flavone c-glucosides from swertia perennis l

Abstract: Identification of xanthones and new arabinosides of flavone C-glucosides from Swertia perennis L. – Seven tetraoxygenated xanthones [1,3,7,8-tetrahydroxy-xanthone (1); 1,8-dihydroxy-3,7-dimethoxy-xanthone (2); 1,7-dihydroxy-3,8-dimethoxy-xanthone (3); 1-hydroxy-3,7,8-trimethoxy-xanthone (4); 3,7,8-trihydroxy-xanthone-xanthone-1-0-β-glucoside (5); 3,7,8-trimethoxy-xanthone-1-0-primeveroside (6); 8-hydroxy-3,7-dimethoxy-xanthone-1-0-primeveroside (7)] have been isolated chromatographically, using polyamide columns, from roots of Swertia perennisL. From leaves and stems of the same plant, six xanthones [1,5,8-trihydroxy-3-methoxy-xanthone (8); 1,5-dihydroxy-3-methoxy-xanthone-8-0-β-glucoside (9); mangiferin (10); 1; 4; 5] and four flavone C-glycosides [iso-orientin (11); isovitexin (12); iso-orientin-6″-arabinoside (13); isovitexin-6″-arabinoside (14)] have also been isolated. Among these compounds, 7, 13 and 14 were not encountered before in nature. In the last two compounds, the position of arabinose on the C-glucoside moiety of the flavone was established by 13C-NMR. spectroscopy.

Chemical Components from Leaves of Fatsia japonica and Their Antitumor Activities in vitro

Abstract: Objective To study the chemical components from the leaves of Fatsia japonica and their antitumor activities in vitro. Methods All compounds were separated and purified by column chromatography over silica gel, Sephadex LH-20 and preparative HPLC. Their structures were identified by physical and chemical properties and spectral methods including 1H-NMR and 13C-NMR. Antitumor assay was measured by MTT method. Results 18 compounds were isolated and identified as palmitic acid (1), β-hydroxypropiovanillone (2), adenosine (3), β-sitosterol (4), daucosterol (5), oleanolic acid (6), echinocystic acid (7), betulinic acid (8), hederagenin(9), hederagenin-3-O-α-L-rhamnopyranosyl(1-->2)-α-L-arabinopyranoside(10), acacetin(11), quercetin(12), quercetin-3-O-β-D-glucopyranoside(13), isovitexin(14), isovitexin-7-O-glucoside(15), astragalin(16), methylpluviatolide(17), and syringaresinol-4-O-β-D-glucopyranoside(18). Conclusion All compounds are isolated from the leaves of Fatsia japonica for the first time except compound 1. The ethyl acetate extract and compounds 6, 10, 12 and 18 at the concentration of 0. 5 mg/mL showed inhibitory effect against the proliferation of colon cell line A549 with the inhibitory rate over 90% in vitro.

Extraction and Quantitative HPLC Analysis of Myricetin in Hydroethanolic extract of Passiflora incarnata (Passifloraceae)

Abstract: Passiflora incarnata has widely been used to treat insomnia, nervous disorders, convulsion, ulcer etc. There has been many flavonoids previously reported in this plant apigenin, luteolin, quercetin, kaempferol, d-allopyranosyl-8-xylopyranosyl-apigenin C-glycosyl flavonoids vitexin, isovitexin, orientin, isoorientin, schaftoside, isoschaftoside, isovitexin- -glucopyranoside, isoorientin-2 -gluco-pyranoside, 2-glucosylapigenin, isoscoparin-2 -glucoside, 2 glucosyl-6-C-glucosylapigenin, 6- -glucopyranosyl-8-d-ribopyranosyl apigenin and swertisin. The percentage of myricetin present in the air dried plant material of HEEPI was calculated as 0.045 %. This is the first time myricetin has been reported in this plant.

HPLC with switching wavelength simultaneous determination of six constituents in Gentiana crassicaulis

Abstract: To establish an HPLC with switching wavelength method for determination of six components(loganic acid,swertiamarin,gentiopicroside,sweroside,isoorientin,isovitexin) in Gentiana crassicaulis.Sepax Gp-C18(150 mm × 4.6 mm,5 μm) column was used,the mobile phase was methanol-0.1% phosphoric acid solution with gradient elution at a flow rate of 1.0 mL·min-1.The column temperature was set at 25℃,detection wavelength was 235 nm(0 ~ 51 min) 、270 nm(51 ~ 57 min) 、243 nm(57 ~ 65 min) 、270 nm(65 ~ 80 min).The six components(loganic acid,swertiamarin,gentiopicroside,sweroside,isoorientin,isovitexin) content in the ranges of 0.01000 ~ 10.0000,0.00216 ~ 2.1600,0.048 ~ 48.0000,0.0010 ~ 1.0000,0.00034 ~ 0.3400 and 0.00026 ~0.2600 μg respectively,had a good linearity.The average recoveries were 98.52% ~ 99.31%,the RSD was less than 3.5%.There were significant correlations between the content of the four iridoid glucosides,the content of the two flavone constituents had correlations too.There was no correlations between the flavone constituents and the iridoid glucosides constituents.Conclusion:This method was simple,rapid,accurate,dependable.And may be use to control quality of Gentiana crassicaulis.