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The phytochemical investigation of both chloroform and ethyl acetate extracts of Centaurea microcarpa Coss. & Dur. led to the isolation of a new cyanogenicglucoside 6'-methacrylate prunasin (3) together with seven known compounds: hydroxy-11β,13-dihydro onopordaldehyde (1), β-sitosterol (2), daucosterol (4), nepetin (5), prunasin (6), astragalin (7) and 7-O-β-D-glucopyranosyl centaureidin (8). Their structures were established by spectral analysis, mainly UV, IR, ESI-MS, 1D & 2D-NMR experiments (COSY, HSQC, HMBC and ROESY).

Chemical constituents and HRMS analysis of an Algerian endemic plant-Verbascum atlanticum Batt.-extracts and their antioxidant activity.

The genus Centaurea contains more than 700 species. It is represented by 45 in Algeria. As part of a systematic examination of the Algerian species, we have investigated C. africana, which is endemic to Algeria. This work concerns the phytochemical study of the ethyl acetate soluble part of the aqueous ethanol extract of the leaves and flowers.Centaurea africana (Asteraceae) was collected during the flowering phase in May 2001, in the East of Algeria, and was authenticated by Pr. A. Kaabeche

<p>To perform a qualitative and quantitative analysis of the phenolic and flavonoid contents and evaluate the antioxidant activity of ethyl acetate (EtOAc) and <em>n</em>-butanol (<em>n</em>-BuOH) extracts of the aerial parts of <em>Genista ulicina </em>Spach. from Algeria.<strong> </strong>The qualitative analysis of plant extracts was carried out by RP-HPLC using UV detector, whereas the quantification of total phenolic and flavonoid contents was completed according to the Folin-Ciocalteu procedure and aluminium chloride colorimetric method respectively. To evaluate the extract's antioxidant activity, Two in vitro antioxidant tests were employed: DPPH and β-carotene bleaching assay. The HPLC/DAD chromatogram showed several peaks indicating the presence of phenolic acids, flavonoids and isoflavonoids in both extracts. The total phenolic content (TPC) ranged from 62.56 and 50.45 mgGAE/g extract, while the total flavonoids content varied between 53.1 and 48.4 mgQE/g extract for EtOAC and <em>n</em>-BuOH respectively. EtOAc extract showed a maximum inhibition value (78.15%) at 150µg/mL using DPPH test and highest antioxidative power (82.42%) using β-carotene bleaching assay comparing with standards. The HPLC-UV analysis showed the richeness of both extracts in phenolic and flavonoid contents. The EtOAc<em> </em>extract exhibited good antioxidant activities comparing to the <em>n</em>-BuOH extract. Thus <em>Genista ulicina</em> could be indicated as a plant of phytopharmaceutical importance.<strong></strong></p>

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