A simplified approach to synthesize nonparticulate (continuous or monolithic) beds with embedded vancomycin chiral selectors for capillary electrochromatography is proposed. In the present approach, N,N'-diallyltartardiamide monomer with diol functionality is used, which can be readily converted to aldehyde groups via periodate treatment. Parallel to the activation of the polymeric matrix for covalent attachment of vancomycin, the periodate treatment has shown secondary effects on the polymeric bed morphology, namely the increase of the average pore size and porosity of the skeleton. Inversed size-exclusion chromatography was applied to characterize porosimetric properties of the capillary columns before and after the periodate treatment. Electroosmotic and enantioselective properties of the nonparticulate beds synthesized are presented. The approach is of more general interest attaching different affinity groups to the polymeric matrix and/or enhancing the accessibility to the active sites, for instance, in the molecular imprinting technique.
Since biological activity of medicinal plants is dependent on cultivation area, climatic conditions, developmental stage, genetic modifications and other factors, it is important to study flora present in different growing sites and geographical zones. This study was focused on screening of antioxidant activity of C. angustifolium harvested in six different locations in Lithuania. The total contents of phenolic compounds, flavonoids and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity were evaluated by spectrophotometric methods. A correlation between radical scavenging activity and total phenolic compounds content was observed (correlation coefficient 0.98). HPLC with online post-column DPPH radical scavenging reaction detection was used for the separation of extracts. Oenothein B, rutin and one unidentified compound were predominant. Volatile compounds were analysed using solid-phase microextraction coupled with gas chromatography-mass spectrometry. Based on the analysis of volatiles, all samples were classified into two chemotypes: (I) with predominant α- and β-caryophyllenes and (II) with predominant anethole.
Four morphotypes -white, pink, deep pink and red -of Achillea millefolium L. are cultiva ted in the collection of medicinal plants at the Kaunas Botanical Garden of Vytautas Magnus University. The colour of linguiform flowers may be affected by a different phenotype or genotype of plants, therefore phytochemical investigations of four yarrow morphotypes were started. The main goal in this work was to evaluate differences in the total content of flavonoids and essential oils and to identify and quantify principal components of essential oils in various Achillea millefolium L. morphotypes. Gas chromatography was used for quantifying essential oil components in flowers and herb. Flowers contained more essential oils than did herb in all morphotypes of Achillea millefolium L. The total content of flavonoids ranged within 0.05-0.07%. The highest content of flavonoids was determined in the deep pink morphotype, and the content of essential oil was highest in the white morphotype of Achillea millefolium L. The total content of flavonoids and the essential oil composition of the white morphotype of Achillea millefolium L. were determined at different vegetation periods.
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