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Desmodium adscendens plant is widely used as juice or tea in various parts of the world against a wide range of diseases. This study determines the quality and the quantity of polyphenols, flavonoids, anthocyanins, and tannins in D. adscendens leaves by UV-spectrophotometry and RP-HPLC methods. In addition, the antioxidant capacity of these phenolic compounds is evaluated by ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic)), DPPH (2,2-diphenyl-1 picrylhydrazyl), and Cellular tests. D. adscendens leaves are mainly composite of flavonoid compounds with 12.8 mg of catechin equivalent (CE)/g dw. The amounts of total polyphenol compounds are 11.1 mg of gallic acid equivalent (GAE)/g dw. The quantity of total anthocyanin and total tannin compounds is not considerable 0.0182 mg CgE/g dw and 0.39 mg CE/g dw, respectively. A direct correlation between phenolic compounds and antioxidant activity is observed (R 2 = 0.96). The RP-HPLC analyses reveal that the main phenolic compound identified in the methanol-water extract is quercetrin dihydrat (2.11 mg/mL). According to the results, it is observed that D. adscendens leaves possess a considerable scavenging antioxidant and antiradical capacity, therefore these antioxidant properties might increase the therapeutic value of this medicinal plant.

Um método de extração de produtos naturais foi desenvolvido. Comparado aos outros métodos, a nova técnica é rápida, mais eficiente e consome menos solvente. A extração de alcalóides de produtos naturais, como Hyoscyamus muticus, Datura stramonium e Ruta graveolens, consiste no uso de uma solução sonicada, contendo um surfactante como agente extrator. Os alcalóides são precipitados pelo reagente de Mayer, dissolvidos em uma solução alcalina, e então, extraídos com clorofórmio. Este artigo compara os resultados obtidos com outros métodos, mostrando claramente as vantagens do novo método.A method of extraction of natural products has been developed. Compared with existing methods, the new technique is rapid, more efficient and consumes less solvent. Extraction of alkaloids from natural products such as Hyoscyamus muticus, Datura stramonium and Ruta graveolens consists of the use of a sonicated solution containing a surfactant as extracting agent. The alkaloids are precipitated by Mayer reagent, dissolved in an alkaline solution, and then extracted with chloroform. This article compares the results obtained with other methods showing clearly the advantages of the new method.

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Euphorbia species possess pharmacological properties that have been widely used for medical purposes worldwide. In this paper, three plants belonging to the Euphorbia genus growing in North-East of Algeria were studied. The phenolic contents were identified using LC-MS, while the fatty acid composition of their fixed oils was determined with GC-MS. The quantification of the total condensed tannins and the leaves' entire anthocyanin content were performed using photometric methods. The main constituents of the polyphenolic compounds identified by LC-MS were ascorbic, chlorogenic, and ellagic acids. The oil yield of the seeds of E. terracina, E. biumbellata, and E. dendroides was 17.48%, 18.5%, and 20.05%, respectively. Quantitative analyses of these oils using GC-MS showed variations in the species' fatty acid constituents' concentrations and compositions. Besides, the phytochemical screening results showed that E. terracina possessed a high amount of tannin and anthocyanin content compared with other studied plants.

Um novo método de extração de óleos de sementes oleaginosas foi desenvolvido. Este método está baseado no uso de solução aquosa de monolaurato de polioxietilenoglicol sorbitano (Tween 20). Comparado com métodos existentes, a nova técnica é rápida e ambientalmente amigável. Em adição, o óleo obtido por este método tem as mesmas propriedades físico-químicas e composição similar àquelas obtidas pelo método clássico com um melhor potencial antioxidante, revelado pelo teste DPPH.A new method of extraction of oils from oleaginous seeds was developed. This method is based on the use of aqueous solution of polyethylene glycol sorbitan monolaurate (Tween 20). Compared with existing methods, the new technique is rapid and environmentally friendly. In addition, the obtained oil by this method has the same physicochemical properties and similar composition as those obtained by the classical method with a better antioxidant potential revealed by DPPH test.