Hamada Haba

Diterpenoids and triterpenoids from Euphorbia retusa.

Six new ent-abietane lactones (1-6), three new esterified tetracyclic triterpenes (7-9), and seven known diterpenoids and triterpenoids were isolated from the roots of Euphorbia retusa. Their structures were elucidated by means of spectroscopic studies including 1D and 2D NMR, mass spectrometry, chemical transformation, and comparison with literature data.

Microphynolides A and B, new spiro-γ-lactone glycosides from Thymelaea microphylla

Two new spiro-γ-lactone glycosides named microphynolide A (1) and microphynolide B (2), together with twelve known compounds including five biflavonoids namely neochamaejasmin A, neochamaejasmin B, daphnodorin B, genkwanol A and stelleranol, one bis-coumarin daphnoretin, two lignans called pinoresinol and matairesinol, one flavonoid glucoside, tiliroside, a sinapyl alcohol glucoside, syringin, and two phytosterols, β-sitosterol and β-sitosterol-3-O-glucoside, were isolated from ethyl acetate extracts of the aerial parts and roots of the plant Thymelaea microphylla Coss. and Dur. All the isolated compounds were characterised by using spectroscopic methods and comparison with the literature data.

Antioxidant and antibacterial activities and polyphenolic constituents of Helianthemum sessiliflorum Pers.

Abstract In this study, the various extracts of aerial parts of Helianthemum sessiliflorum Pers. were examined in vitro for possible source of antioxidants and for antibacterial activity. The antioxidant activity was performed by DPPH radical scavenging method which showed that ethyl acetate extract possessed the best antioxidant potential (IC50 = 32.75 ± 2.07 μg/mL). The significant linear correlation was realised between the values of the total phenolic/flavonoid content and antioxidant activity of plant extracts. The ethyl acetate and n-butanol extracts showed moderate antibacterial activity. In addition, the phytochemical study of n-butanol extract afforded nine known phenolic compounds (1–9). This is the first report of six of them (1, 3, 5–8) in Cistaceae family. The structural identification of the isolated compounds was achieved using several spectroscopic methods.

New methylated flavonol glucosides from Fumana montana Pomel

Three new methylated flavonol glucosides: 3-methoxy-7-O-β-(6″-galloylgluco-pyranoside) quercetin (1), 3,4′-dimethoxy-7-O-β-(6″-galloyl-glucopyranoside) quercetin (2) and 3-methoxy-7-O-β-(6″-galloylgluco-pyranoside) kaempferol (3), in addition to six known flavonols, were isolated from the ethyl acetate extract of Fumana montana Pomel. Their structures were assigned by spectroscopic methods.

Phytochemical components and biological activities of Silene arenarioides Desf.

Abstract In this study, six known compounds 1–6 were isolated from the aerial parts of Silene arenarioides Desf. using different chromatographic methods. The structures of these compounds were identified as maltol glycoside (1), soyacerebroside I (2), chrysin (3), apigenin (4), quercetin (5) and stigmasterol glucoside (6). The compounds (1) and (2) are reported for the first time from this genus. The isolated compounds were determined using NMR techniques (1H NMR, 13C NMR, COSY, HSQC and HMBC) and mass spectroscopy (ESI-MS). The antibacterial and antioxidant activities of extracts and of compound (1) have been evaluated. The antioxidant activity was performed by DPPH radical scavenging method, which showed that methanol extract possesses a good antioxidant activity with value of IC50 = 8.064 ± 0.005 μg/mL.

Chemical composition, antioxidant and antibacterial properties of Pteranthus dichotomus from Algerian Sahara.

The phytochemical study of ethyl acetate and n-butanol extracts of Pteranthus dichotomus Forssk. led to the isolation and identification of 11 compounds, including three glycolipids 1–3, one lignan 4, three flavonoids 5–7 and four phytosterols 8–11. Structures of the isolated compounds have been elucidated by analysis of 1D and 2D NMR data, and mass spectrometry EI-MS and ESI-MS and by comparison with literature data. Furthermore, the ethyl acetate and n-butanol extracts were examined for their antioxidant and antibacterial activities. The results showed that both extracts (PDAC and PDBU) had a moderate antioxidant activity (IC50 = 375.514 μg/mL and 691.333 μg/mL) respectively.