Sesquiterpene Lactones with the 12,8-Guaianolide Skeleton from Algerian Centaurea omphalotricha

In continuing our investigation on the chemical diversity of Algerian plants, we examined Centaurea omphalotricha, whose chemical composition has been poorly studied. The present work was aimed at characterizing the secondary metabolite pattern of the CHCl3 extract of the aerial parts of this plant that displayed antiproliferative properties in a preliminary screening on HeLa cell line. The chemical analysis led us to characterize the bioactive oxygenated terpenoid fraction which includes, within major known metabolites, two new minor sesquiterpene lactones, centaurolide-A (1) and centaurolide-B (2). The structures of two compounds exhibiting the 12,8-guaianolide skeleton were determined by spectroscopic methods as well as by chemical correlation with inuviscolide (3), a well-known bioactive guaianolide isolated from Dittrichia (=Inula) viscosa. Centaurolides A and B represent the first report of 8,12-guaianolide skeleton in Centaurea genus. The effect of new compounds 1 and 2 and inuviscolide (3) on HeLa cell has also been evaluated

Determination of Total Phenolic and Flavonoid Contents and Evaluation of Antioxidant Activity of an Algerian Medicinal Species, Arbutus serratifolia Salisb: Arbutus serratifolia Salisb

Arbutus serratifolia Salisb. is known as a strawberry tree belonging to the Ericaceae family and represents a Mediterranean evergreen shrub. The species distributed in the forest of El Milia region (Jijel) was chosen as a specimen for chemical investigation and biological evaluation for the first time from this region. The MeOH extract of the aerial parts underwent qualitative phytochemical screening using conventional techniques. While CHCl3, EtOAc, n-BuOH, and even MeOH fractions were subjected to quantitatively determine the total phenolic and flavonoid contents using the Folin-Ciocalteu and Aluminium trichloride methods respectively. The antioxidant potential of these fractions was assessed using the DPPH scavenging activity, ABTS cation radical reduction, CUPRAC reducing capacity and Phenanthroline assays. This study revealed that A. serratifolia Salisb. fractions are endowed with potent antioxidant activity; thus, it is worth noting that this plant could be used as a rich food source for a wide range of phenolic compounds, particularly of new antioxidant agents

Chemical constituents and HRESI-MS analysis of an Algerian endemic plant - Verbascum atlanticum batt. - extracts and their antioxidant activity.

This is the first report on the phytochemistry and antioxidant activity of ethyl acetate and n- butanol extracts from an Algerian endemic plant Verbascum atlanticum Batt. (Scrophulariaceae). Both extracts were subjected to a phytochemical study by semi-preparative HPLC, which led to the isolation and identification of nine compounds: methyl linolenate (1), methyl linoleate (2), Phytol-1(3), Martynoside (4), Isomartynoside (5), Cis-martynoside (6), Ilwensisaponin C (7), Ilwensisaponin B (8), Ilwensisaponin A (9). In addition, the fractions from both extracts were analysed by LC-UV-MS and HRESI-MS. This later revealed the presence of eight other metabolites by using a comparison with known microbial metabolites data. Finally, both extracts were estimated for their phenolic and flavonoid contents as well as the evaluation of their antioxidant activity using five different assays DPPH, CUPRAC, reducing power, β-carotene bleaching and superoxide DMSO alkaline. The results showed that the ethyl acetate extract had the most antioxidant effect

HPLC-UV profile of Genista ulicina Spach. (Fabaceae) extracts and in vitro antioxidant activity

To perform a qualitative and quantitative analysis of the phenolic and flavonoid contents and evaluate the antioxidant activity of ethyl acetate (EtOAc) and n-butanol (n-BuOH) extracts of the aerial parts of Genista ulicina Spach. from Algeria. 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 n-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 extract exhibited good antioxidant activities comparing to the n-BuOH extract. Thus Genista ulicina could be indicated as a plant of phytopharmaceutical importance

Chemical Composition of Algerian Thymus algeriensis Boiss. & Reut. and Marrubium vulgare L. (Lamiaceae) Essential Oils from the Aures Region

International audienceThis study was aimed to determine the chemical composition of essential oils obtained from aerial parts of Thymus algeriensis Boiss. & Reut. and Marrubium vulgare L. collected in the Aures region of Algeria. Essential oils were extracted by steam distillation method and analyzed using GC-MS and GC-FID techniques. Thirty-five (35) and twenty-nine (29) components were identified respectively in T. algeriensis and M. vulgare essential oils to represent respectively 94.8% and 75.7% of the total oil composition. The main compounds of T. algeriensis oil were germacrene D (29.6%), β-caryophyllene (11.0%), E-β-farnesene (7.8%), bicyclogermacrene (4.4%) and δ-cadinene (4.0%), while, β-bisaboene (36.3%), β-caryophyllene (7.8%), phytol (6.2%), nonacosane (4.0%) and heptacosane (3.3%) were the main components of M. vulgare oil. The richness of these two oils in germacrene D and β-bisaboene respectively could suggest a new bioactivity

Centaurea microcarpa Coss. & Dur. (Asteraceae) extracts: New cyanogenic glucoside and other constituents

The phytochemical investigation of both chloroform and ethyl acetate extracts of Centaurea microcarpa Coss. & Dur. led to the isolation of a new cyanogenic glucoside 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).Peer Reviewe

A new flavonoid and other constituents from Centaurea nicaeensis All. var. walliana M.

A new flavone glucoside, apigenin 4′-(6″-methylglucuronide) (1), together with six known compounds, cirsilineol, jaceosidin, melitensin, apigenin, apigenin 7-(6″-methylglucuronide) and prunasin, were isolated from the ethanolic extract of the aerial parts of Centaurea nicaeensis All. var. walliana M. (Asteraceae) collected from Souk-Ahras, eastern Algeria. The structures were established by spectral analysis, mainly HRESI-MS, UV and 2D-NMR experiments (COSY, HSQC and HMBC).This study was supported by Algerian FNR program and by the PCI-Mediterranean project (A/023594/09) from Ministerio de Asuntos Exteriores y de Cooperacción-AECID

Preliminary phytochemical screening, analysis of phenolic compounds and antioxidant activity of Genista cephalantha Spach. (Fabaceae)

This study was designed to estabilish a preliminary phytochemical screening, evaluate the phenolic and flavonoid content according to the Folin-Ciocalteu procedure, and aluminum chloride method respectively and to determine qualitatively, using HPLC-UV method, the most important products present in ethyl acetate (EtOAc) and n-butanol (n-BuOH) extracts of the aerial parts of Genista cephalantha Spach. from east Algeria. The antioxidant activity of these extracts was spectrophotometrically tested by measuring their ability to scavenge a stable DPPH free radical and by β-Carotene/linoleic acid bleaching assay. Evaluated extracts showed a good activity in both antioxidant system assays

A new flavonoid and other constituents from Centaurea nicaeensis All. var. walliana M.

International audienc

Preliminary phytochemical screening, analysis of phenolic compounds and antioxidant activity of Genista cephalantha Spach. (Fabaceae)

This study was designed to estabilish a preliminary phytochemical screening, evaluate the phenolic and flavonoid content according to the Folin-Ciocalteu procedure, and aluminum chloride method respectively and to determine qualitatively, using HPLC-UV method, the most important products present in ethyl acetate (EtOAc) and n-butanol (n-BuOH) extracts of the aerial parts of Genista cephalantha Spach. from east Algeria. The antioxidant activity of these extracts was spectrophotometrically tested by measuring their ability to scavenge a stable DPPH free radical and by β-Carotene/linoleic acid bleaching assay. Evaluated extracts showed a good activity in both antioxidant system assays