Phytochemical analysis, antioxidant and antimicrobial activities of leaves and flowers ethyl acetate and n-butanol fractions from an Algerian endemic plant Calycotome spinosa (L.) Link

Calycotome spinosa (L.) Link is one of the important plants in traditional medicine especially in Algeria. The present work deals with the phytochemical screening, the flavonoids extraction from leaves and flowers of this plant, the quantification of total polyphenols and flavonoids, as well as the evaluation of antioxidant and antimicrobial properties of ethyl acetate and n-butanol fractions. While, the rest, interacted with its phenolics identification. The results of preliminary phytochemical screening showed that C. spinosa contained various metabolites: Polyphenols, flavonoids, alkaloids, saponins etc. In addition, the findings of polyphenols determination using Folin Ciocalteu was high in all the fractions: 107.75±0.41 and 64.24±1.81 mg gallic acid equivalents/g extract for leaves ethyl acetate and n-butanol respectively and 81.45±0.6 and 96.06±2.72 mg gallic acid equivalents/g extract for flowers ethyl acetate and n-butanol successively. Conversely, the flavonoids content in the four fractions by AlCl3 was less important than polyphenols. Moreover, the obtained fractions were evaluated for their antioxidant capacity using DPPH assay. Besides, the obtained result revealed that Ethyl acetate and n-butanol fractions of leaves exerted very high antioxidant activities with IC50 equal to 45.25±1.8 and 52.80±2.05 µg/mL, respectively compared with flowers. Furthermore, the antimicrobial activity of those fractions against many microbial strains have also been investigated using the disc diffusion method; the leaves ethyl acetate fraction showed the highest activity against Acinetobacter baumannii with a zone inhibition diameter equal to 22±0.06 mm. Additionally, high-performance liquid chromatography/diode-array detector (HPLC/DAD) analysis performed with C. spinosa fractions revealed the richness of plant in many phenolic compounds.   Key words: Calycotome spinosa (L.) Link, medicinal plant, phenolics and flavonoids content, antioxidant activity, antimicrobial potential, high-performance liquid chromatography/diode-array detector (HPLC/DAD).