Mohamed Yousfi

Isolation and characterization of a new steroid derivative as a powerful antioxidant from Cleome arabica in screening the in vitro antioxidant capacity of 18 Algerian medicinal plants.

Hydromethanolic extracts from 18 Algerian medicinal plants were screened for their phenolic contents and radical scavenging activities. The phenolic extract of Cleome arabica (Capparaceae) was found to be the most active one. Purification of this extract by semi-preparative high performance liquid chromatography led to the isolation and identification of new steroid derivative. The structure of the active principle is proposed as (17-(4-hydroxy-1,5-dimethylhexyl)-2,3,7-(acetyloxy) gona-1,3,5(10)-trien-15-ol). Compared to six other standard antioxidants which were ascorbic acid, α-tocopherol, Trolox, (+) catechin, p-coumaric acid and gallic acid, the isolated compound was found to be significantly more active in the radical scavenging assay using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Similar results were obtained in the hemolysis assay. The antioxidant capacities of the methanolic extract of C. arabica and its principle compound indicate that this plant may be an important source of chemopreventive and chemotherapeutic natural products activity.

Isolation and characterization of a new hispolone derivative from antioxidant extracts of Pistacia atlantica.

The quantification of the total phenolic compounds of Pistacia atlantica showed that the different parts of the tree are rich in natural phenolic compounds. The antioxidant tests proved that the phenolic extracts have a strong antioxidant activity. The positive correlation between the Trolox equivalent antioxidant capacity (TEAC) and the amount of phenolic compounds confirms their contribution to the antioxidant activity. Among the various phenolic compounds isolated and characterized by spectroscopic methods, a new natural antioxidant 1 (methyl 5‐(3,4‐dihydroxyphenyl)‐3‐hydroxypenta‐2,4‐dienoate) derived from hispolone 2 has been isolated from the mushroom Inonotus hispidus growing on Pistacia atlantica. Hispolone 2 (6‐(3,4‐dihydroxyphenyl)‐4‐hydroxyhexa‐3,5‐dien‐2‐one) and hispidin 3 (6‐(2‐(3,4‐dihydroxyphenyl)vinyl)‐4‐hydroxy‐2H‐pyran‐2‐one) have been also identified using spectroscopic methods, including 2D‐NMR and EI‐MS. Copyright

Chemotypes of essential oil of unripe galls of Pistacia atlantica Desf. from Algeria.

The essential oils (EOs) of unripe galls (from male and female plants) of a total number of 52 samples of Pistacia atlantica collected from different regions in Algeria were analysed by GC/MS and GC. The yields of the extraction of the EO by hydrodistillation vary from low to high values (0.08–1.89% v/w). The results of both methods of principal component analysis and hierarchical ascendant classification revealed the presence of two different chemotypes: α-pinene chemotype and α-pinene/sabinene/terpinen-4-ol chemotype.

The in vitro evaluation of antioxidative activity, α-glucosidase and α-amylase enzyme inhibitory of natural phenolic extracts.

Phenolic extracts from the medicinal parts of six traditional Algerian herbs were tested in screening experiments for the antioxidant, α-amylase and α-glycosidase inhibiting activities. UV-analysis of the extracts from the plants indicated that the total phenols content was ranged between 0.48 and 3.46 mg equivalent of gallic acid per gram of dry matter, whereas the flavonoids content expressed as rutin equivalent per gram of dry matter was ranged between 0.18 and 2.23 mg/g. The study of antioxidant activity by scavenging the hydroxyl radical (OH), the nitroxide radical (NO) and the stable radical cation (ABTS(+)) showed a high antioxidant power. Also, these extracts illustrated a significant reductive power of the Fe(3+)-TPTZ complex. Similarly, we have found that the phenolic extracts exhibit an imperative antioxidant status compared to synthetic antioxidants. The study of the extract effects shows that Anabasis articulata, Agatophora alopecuroide and Heliantheum kahiricum extracts have a powerful inhibiting capacity of the α-amylase and α-glycosidase with a Ki values less than 10 μM. Our study, for the first time, revealed the anti-diabetic potential of the six plants and the results of this study could be helpful to develop medicinal preparations or nutraceuticals and functional foods for diabetes.

Chemical Composition of the Essential Oil of Unripe Galls of Pistacia atlantica Desf. from Algeria

The essential oils obtained by hydrodistillation of unripe galls of Pistacia atlantica and collected from both male and female trees yielded 0.53% and 0.46% v/w, respectively. The essential oils were analyzed by GC and GC-MS showing the occurrence of a new  3 -carene rich chemotype showing a content of 75.34%. The second is the well known chemotype � -pinene/� -pinene, which is rich in � -pinene (59.01%) and � -pinene (13.26%).

Fatty acid profile, tocopherols content and antioxidant activity of algerian pumpkin seeds oil (Cucurbita pepo L)

Cucurbita Pepo (Pumpkin) is a plant which is traditionally used to treat a wide variety of diseases, and through scientific investigation most of the properties have been validated. However, more scientific data is needed to support the various health claims. The aim of this study was to determine the fatty acids (FA) and Triacylglycerols (TAG) composition, tocopherols content and to evaluate the antioxidant activity of eight pumpkin seeds oil cultivated in Algeria. The results indicated that pumpkin seeds were rich in oil (15.8–33.5%) and the major unsaturated fatty acids were linoleic acid (42.1–48.5%) followed by oleic acid (18.4–39.6%), while the main saturated fatty acids were palmitic (13.91–20.00%).Unsaturated FA showed a preference for the internal position. Linoleic and oleic acids occurred predominantly in the sn-2 position as generally found in vegetable oils. The main TAGs were triunsaturated GU3 and monosaturated GSU2 as majorities compounds. The tocopherol content of the oils ranged from 7.7 to 31.9 mg/kg of oil for -tocopherol, from 39.3 to 155.1 mg/kg for ( + )-tocopherol, and from 39.0 to 103.0 mg/kg for δ-tocopherol. The capacity that would be suitable for food and industrial applications, as well as high unsaturation FA and tocopherol content that could potentially improve the nutrition of human diets.The data of antioxidant power determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and phosphomolybdenum (PPM) complex methods show that the level of the antioxidant activity by two used assays was significantly compared to synthetic antioxidants. Also, it was demonstrated for the first time that the studied oils possessed a good antioxidant activity which may be associated with their alleged health benefits.

Harmaline and hispidin from Peganum harmala and Inonotus hispidus with binding affinity to Candida rugosa lipase: In silico and in vitro studies.

The inhibitory effect of phenolic compounds and alkaloids of Inonotus hispidus and Peganum harmala on Candida rugosa lipase was investigated, also, their antioxidant activities using DPPH, ABTS and phosphomolybdenum were studied in this paper. The phenolic extracts have shown a stronger antiradical activity than the alkaloids extracts. The enzymatic inhibition produced by these extracts is described here for the first time. The results have shown that the phenolic and the alkaloid extracts are good inhibitors of C. rugosa lipase. Thus, the inhibitor molecules (harmaline and hispidin) have been isolated from P. harmala and I. hispidus. Their structures were elucidated by (1)H NMR analysis. Molecular docking has been achieved using AutoDock Vina program to discuss the nature of interactions and the mechanism of inhibition. Therefore, these isolated molecules could be used in the treatment of candidiasis.

Twenty Traditional Algerian Plants Used in Diabetes Therapy as Strong Inhibitors of α-Amylase Activity

In the present work, we have studied the inhibitory effects of aqueous and alcoholic extracts of six Algerian medicinal plants known by their therapeutic virtues against diabetes. The total phenolic compounds content, assayed using Folin-Ciocalteu’s reagent, of the samples ranged from 0.183 mg/g to 43.088 mg/g and from 1.197 mg/g to 7.445 mg/g, expressed as gallic acid equivalent (GAE), for the, respectively, whereas the total flavonoids concentrations, detected using 2% of the aluminium chloride, ranged from 0.41 mg/g to 11.613 mg/g and from 0.0097 mg/g to 1.591 mg/g, expressed as rutin equivalents (RE), for the aqueous and methanolic extracts, respectively. The major plants were found to inhibit enzymatic activities of Aspergillus oryzae-amylase in a concentration dependent manner. The values of the inhibition constants () have been determined according to the Dixon and Lineweaver-Burk methods. The results showed that the values were less than 55 ppm for the all extracts. A strong inhibition was found in the phenolic extract of Salvia officinalis with a of 8 ppm.

New chemotype of essential oil of Achillea santolina L. collected from different regions of Algeria

Chemical composition of essential oil (EO) obtained by hydrodistillation of the aerial parts of Achillea santolina L. was analysed using GC and GC–MS. Especially, this study involved a large scale investigation, using different regions in which, five flowering wild growing populations collected from the high plateau of Algeria were engaged. Unlike previous reports, the current investigation showed very high EO yields for this plant (up to 1.7% w/w “dw”). The main result of the current study was the occurrence of a new chemotype rich in camphor (39.54–67.86%) and 1,8-cineole (7.14–8.57%).

Inhibition of Candida rugosa Lipase by Secondary Metabolites Extracts of Three Algerian Plants and their Antioxydant Activities

Lipase inhibitors have generated a great interest because they could help in the prevention or the therapy of lipase‐related diseases. Therefore, the aim of this work was to evaluate the inhibitory effect of secondary metabolites extracts such as phenolic compounds and saponins of three Algerian medicinal plants: Achillea santolina, Inonotus hispidus and Zizyphus lotus, indeed their antiradicalaire activity using DPPH• (1, 1‐diphenyl‐2‐picryl‐hydrazyl). The phenolic extracts have shown a strong antiradicalaire activity than the saponin extracts with EC50 values ranged from 6 to 11 μg/ml and from 51 to 82 μg/ml, respectively. The enzymatic inhibition produced by these plant extracts is described here for the first time. The results have shown that the phenolic extracts are more potent than the saponin extracts with Ki values ranged from 0.011 mg/ml to 0.027 mg/ml for phenolic extracts, and ranged from 0.071 mg/ml to 0.69 mg/ml for saponin extracts. The nature, mechanism and possible physiological relevance of lipase inhibition by extract components