Avaliação da atividade antimicrobiana de diferentes extratos da Macroalga castanha padina boryana sobre estirpes bacteriana (Pseudomonas aeruginosa) e fúngica (Candida albicans)

Abstract

In recent times, microorganisms have been showing resistance to synthetic antibiotics, which shows that it is extremely important to search for new sources of natural compounds with antimicrobial properties. Among macroalgae, Phaeophyceae, brown macroalgae, have been shown to have metabolites such as polysaccharides, phlorotannins, carotenoids and sterols of great interest to the pharmaceutical industry. The metabolites of brown macroalgae have several pharmacological activities, such as antioxidant, antitumor, antifungal, antiviral or antibacterial activity, among others, which may constitute an added value in the development of new drugs. The present study aimed to evaluate the antimicrobial potential of the brown macroalgae Padina boryana collected on the island of Nhaca, Maputo Bay in Mozambique, as well as to identify bioactive compounds present in the macroalgae. The samples were washed, dried and crushed. The dry powder was extracted using different solvents (acetone, hexane and methanol) using the maceration technique. To evaluate the antimicrobial activity of the different extracts of brown macroalgae, the disk diffusion method was used on Mueller-Hinton and Sabouraud agar plates against two strains of microorganisms pathogenic to humans. Based on the results, it was possible to observe that the three extracts of brown macroalgae showed antimicrobial potential on the growth of P. aeruginosa and C. albicans, with the formation of inhibition halos ranging from 12 to 35.8 mm in diameter. The phytochemical composition was analyzed using GC-MS (gas chromatography-mass spectrometry) and identified based on the NIST mass spectral library. Twenty-seven phytocompounds were identified, and the following were common to the three extracts: Stigmasta-5,24(28)-dien-3-ol, (3.beta.,24Z)- and to the extracts with acetone and methanol: 2-Pentadecanone, 6,10,14-trimethyl-; 3,7,11,15-Tetramethyl-2-hexadecen-1-ol; n-Hexadecanoic acid; 6 Hydroxy-4,4,7a-trimethyl-5,6,7,7atetrahydrobenzofuran-2(4H)-one; Phytol and Stigmasta-5,24(28)-dien-3-ol, (3.beta.,24Z)- The results of the present work on the macroalgae Padina boryana make it a target for new studies for the discovery of bioactive compounds with antimicrobial properties(TRADUÇÃO NOSSA)