Showing papers on "Isovitexin published in 1983"
TL;DR: Two isovitexin 2″-O -glycosides have been isolated from primary leaves of rye and identified as IsoviteXin 2 O -arabinoside and Isovitesin 2 2 O-glycoside.
10 citations
TL;DR: An attempt is made to characterize the phytochemical properties of trans-sinapic acid methyl ester in Vepris heterophlylla by isolating the polypeptide O-glucosylvitexin from the leaves of the plant.
8 citations
TL;DR: Quartz optic microscopy with variable wavelength illumination was used to locate and quantify the ultraviolet absorbing flavone isovitexin 7-0-qlucoside in leaf and petal epidermis in Silene pratensis.
Abstract: Quartz optic microscopy with variable wavelength illumination was used to locate and quantify the ultraviolet absorbing flavone isovitexin 7-0-qlucoside in leaf and petal epidermis in Silene pratensis. Mean vacuolar absorption spectra and mean cell wall thickness were used to estimate flavone contents in different organs. The flavone spectrum in vivo coincides with that found in vitro (absorption peaks at 273 and 335 nm). Flavone concentration in the green leaves is determined by the light levels under which individual plants were raised; with low levels (8,000 lux) a few upper epidermal cells show faint absorption at 335 nm. In plants raised at 18,000 lux, 60–70 % of the upper epidermal cells absorbed at 334 nm and flavone concentration in the absorbing cells was 1–3 mM. In plants raised under high light intensity (36,000 lux), most of the upper epidermal cells absorbed at 335 nm and the flavone concentration in the cells ranged from 8.5 to 15 mM. In the high light intensity plants some lower epidermal cells also absorb at 335 nm (flavone concentrations 2–5 mM). In all plants investigated, nearly all the cells of the upper epidermis of the netals absorb strongly at 335 nm (concentrations exceeding 19 mM).
7 citations
TL;DR: Epidermis cells of Silene pratensis mutants unable to glycosylate isovitexin show a variety of internal and structural aberrations and either globular, or crystal-like, or clew-like structures are present.
Abstract: Epidermis cells ofSilene pratensis mutants unable to glycosylate isovitexin show a variety of internal and structural aberrations. In cells of mutants able to glycosylate isovitexin, the flavone-glycoside containing vacuole appears to occupy the whole cell. In cells of mutants unable to glycosylate isovitexin either globular, or crystal-like, or clew-like structures are present. These inclusions consist for the largest part of isovitexin. The nucleus has often moved to the sidewalls and is frequently degenerated. The shape os the cells, especially those with a clew-like structure, is often bladder-like swollen.
7 citations
TL;DR: Four 7,2″-di-O-glycosyl-6-C- Glycosylflavones were isolated from Cerastium arvense, including two new compounds: isomollupentin 7,O-glucoside-2″ -O-arabinoside and isomollsupentin 6,2′-o-xyloside.
4 citations
TL;DR: The galactosyltransferase activity was optimal at pH 7.0; the divalent ions Zn and Hg were inhibitory, whereas Ca, Co, Mg, Mn and EDTA were not inhibitory.
Abstract: Enzyme activity responsible for the biosynthesis of isovitexin-7-O-galactoside from isovitexin and UDP-galactose can be demonstrated in protein extracts of cotyledons and rosette leaves from Silene pratensis plants. This galactosyltransferase activity is absent in stem leaves and petals. “True Km” values of 0.0025 mᴍ for isovitexin and of 8.2 mᴍ for UDP-galactose were found. At infinite concentration of both substrates the “true Vmax” value was 0.11 mᴍ/min/mg protein. The galactosyltransferase activity was optimal at pH 7.0; the divalent ions Zn and Hg were inhibitory, whereas Ca, Co, Mg, Mn and EDTA were not inhibitory.
3 citations