A new isoflavonoid derivative, evaluation of the antioxidant capacity and phenolic content of Genista lobelii DC.

The phytochemical investigation of both chloroform and ethyl acetate extracts of Genista lobelii DC from an Algerian endemic plant led to the isolation of a new isoflavonoid Aspalathoidin compound (1) and nine known compounds (laburnetin, isokaempferide, retamasin B, ephedrodin, sakuretin, isoprunetin, genistein -7-O-ß-glucoside, derrone-4'-O-methyl ether and eriodictyol-7,3'-dimethylether). Twelve phenolic compounds were identified in ethyl acetate and n-butanol extracts through a qualitative investigation of phenolic compounds using HPLC. 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, ABTS, GOR and the sun protection factor SPF was determined as an index of the photoprotective capacity of the G.lobelii DC extracts. The extract of chloroform and ethyl acetate has good antioxidant and includes significant levels of phenolic and flavonoid components.

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, ß-carotene bleaching and superoxide DMSO alkaline. The results showed that the ethyl acetate extract had the most antioxidant effect.

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-11ß,13-dihydro onopordaldehyde (1), ß-sitosterol (2), daucosterol (4), nepetin (5), prunasin (6), astragalin (7) and 7-O-ß-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).