abstract
The chemical composition, investigated by gas chromatography-mass spectrometry, and antibacterial activity of lipophilic extractives of three varieties of Opuntia ficus-indica roots from Algeria are reported in this paper for the first time. The results obtained revealed a total of 55 compounds, including fatty acids, sterols, monoglycerides and long chain aliphatic alcohols that were identified and quantified. beta-Sitosterol was found as the major compound of the roots of the three varieties. Furthermore, considerable amounts of essential fatty acids (omega 3, omega 6, and omega 9) such as oleic, linoleic, and linolenic acids were also identified. The green variety was the richest among the three studied varieties. The antibacterial activity, evaluated with disc diffusion method, revealed that lipophilic extracts were effective mainly against Gram-positive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) (19 similar to 23 mm). Gram-negative strains mainly Pseudomonas aeruginosa gave an inhibition zone of 18 mm, which is considered high antibacterial activity. The minimal inhibitory concentrations of the tested bacteria revealed interesting values against the majority of bacteria tested: 75-100 mu g mL(-1) for Bacillus sp., 250-350 mu g/mL for the two Staphylococcus strains, 550-600 mu g mL(-1) for E. coli, and 750-950 mu g mL(-1) obtained with Pseudomonas sp. This study allows us to conclude that the lipophilic fractions of cactus roots possess interesting phytochemicals such as steroids, some fatty acids and long chain alcohols that acted as antibiotic-like compounds countering pathogenic strains.
keywords
SATURATED FATTY-ACIDS; CHEMICAL-CHARACTERIZATION; ANTIMICROBIAL ACTIVITY; ANTIOXIDANT PROPERTIES; BIOLOGICAL-ACTIVITIES; PHYTOCHEMICAL CONTENT; PHENOLIC COMPOSITION; INHIBITORY-ACTIVITY; OXIDATIVE STRESS; L.
subject category
Biochemistry & Molecular Biology; Chemistry
authors
Benramdane, E; Chougui, N; Ramos, PAB; Makhloufi, N; Tamendjari, A; Silvestre, AJD; Santos, SAO
our authors
Armando Jorge Domingues Silvestre
Full professor
Patrícia Alexandra Bogango Ramos Portela
Post-Doc Fellowship
Sónia Andreia Oliveira Santos
Assistant ResearcherProjects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
acknowledgements
This work was carried out under the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC). FCT is also acknowledged for the research contract under Scientific Employment Stimulus to S. Santos (2021.03348.CEECIND). The authors also thank the University of Bejaia and the Direction Generale de la Recherche Scientifique et Developpement Technologique, Algeria, for their support.