Search

The argan tree is an endemic plant of Morocco that plays a great socio-economical and ecological impact in the south of the country. This plant is well known for the oil extracted from the almond, characterized by high nutritional value and its large spectrum of uses. This study aims to evaluate the chemical composition and the physicochemical parameters of fixed oils produced by the argan trees introduced in Oujda City and to compare them with other oils produced by the same trees in their natural biotope in the northeast and southwest of Morocco. The obtained results indicated that the oil yield varies between 57.65% and 47.60%. The investigation of the chemical composition using HPLC-DAD showed the presence of three types of tocopherols: α-tocopherols (9.7%), δ-tocopherols (6.6%), and γ-tocopherols (83.6%), the total content of tocopherols vary between 323.86 and 553.12 mg/kg. While, the methyl esters analysis using GC-MS showed the presence of 4 main fatty acids: oleic acid (55.40–41.14%), linoleic acid (36.92–26.75%), palmitic acid (18.69–9.97%) and stearic acid (12.09–3.68). The physicochemical parameters (the free acidity, the peroxide value, and the specific extinction) indicated that the different tested oils are characterized by a good oil quality according to the Moroccan standard concerning argan oil (NM 08.5.090). The obtained results indicated that the introduced argan in Oujda City showed a quality and a chemical composition that was comparable to that produced in the natural area of the argan tree, which shows the plasticity the plant under different climatic and edaphic conditions. These results emphasize the encouragement of the introduction of this species at a high level in eastern Morocco. [ABSTRACT FROM AUTHOR]

Background: Ethanolic, aqueous and lipidic extracts of Spirulina platensis were evaluated for their bioactive substances (polyphenols and fatty acids) and antioxidant activities using two different assays diphenyl-1-picrylhydrazyl (DPPH) and azino-bis (ethylbenzthiazoline-6- sulfonicacid (ABTS)). Methods: The phenolic compounds amounts were determined by colorimetric assays and were analyzed by high-performance and liquid chromatography (HPLC) method. The identification of phenolic compounds in the extract was accomplished by comparison of their retention times with those of pure standards. The chemical composition of fatty acids in lipidic extract was determined by GC/FIDs and GC/MS method. Results: The obtained results revealed that using DPPH, the ethanolic extract recorded the highest activity with (IC50=449 μg/mL ± 83). It was characterized with a high levels of phenolic and flavonoid content 0.33 ± 0.01 mg GAE/g dw and 0.21 ± 0.01 mg quercetin/g dw, respectively. The ethanolic extract showed the presence of caffeic acid, syringic acid, ferulic acid, p-coumaric acid, chlorogenic acid, kaempferol, quercetin and apigenin. Those entire phenolic compounds seem participle synergistically to the pronounced higher activity. To the best of our knowledge, the apigenin (4′, 5, 7,-trihydroxyflavone), a natural compound which is famously known by its potent antiradical activity, was identified for the first time in Moroccan S. platensis only in the ethanolic extract. A high positive correlation (r=0.895) between the antioxidant activity and the chemical composition of ethanolic extract was observed. For ABTS, lipidic extract showed the highest activity with (IC50=740 μg/mL ± 12). A total of 15 fatty acids compounds, amounting 89.73% of the extract were identified. γ-linolenic acid (GLA) (39.02%) and α-linolenic acid (ALA) (13.85%) were the major component and contribute greatly to the antioxidant activity observed. The lipidic extract has a high content of unsaturated fatty acids (70.95%) which are often exhibited very high antioxidant activity since they have two or more double bonds and chain lengths. The aqueous extract either with DPPH or ABTS methods, recorded low antioxidant activity. Its correlation was r=0.499, lower than found in the ethanolic extract. Conclusions: These results showed that Spirulina platensis could be considered as a valuable source of fatty acids and phenolics with potent antioxidant activity. It may be employed in the manufacture of pharmaceutical drugs as an alternative source of natural antioxidants. [ABSTRACT FROM AUTHOR]