First report on phytochemical investigation, antioxidant and antidiabetic activities of Helianthemum getulum.

A new flavonoid, 5,7,2',4',5'-pentahydroxyflavone 3-O-ß-D-galactopyranoside (12) and twelve known derivatives: an aryltetralin-lignan (3), seven flavonoids (4-5, 7-10, 13) and four phenolic acids (1-2, 6, 11) have been isolated from the aerial parts of Helianthemum getulum Pomel. (Cistaceae family) an endemic species to the septentrional Sahara that is being studied for the first time. Structure elucidation of the isolated compounds was established by means of spectroscopic methods especially NMR and Mass Spectrometry. In vitro antioxidant (DPPH, ABTS, GOR and CUPRAC assays) and antidiabetic (micro-dilution method) activities of the crude extract, fractions and isolated compounds were performed. The new flavonol (12) and Compounds (2, 3, 7, 9) were found to be the most active, some of them exhibiting better activity than the antioxidant standards. Compounds 7, 9 and 3 showed higher α-glucosidase inhibitory activity compared to standard acarbose (IC50= 2.70 ± 0.03 µM, 3.09 ± 0.03 µM, 37.28 ± 1.20 µM and 275.43 ± 1.59 µM, respectively).

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.