Browsing by Author "Abreu, Rui M. V."
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- Antimicrobial activity of phenolic compounds identified in wild mushrooms, SAR analysis and docking studiesPublication . Alves, M. J.; Ferreira, I. C. F. R.; Froufe, H. J. C.; Abreu, Rui M. V.; Martins, A.; Pintado, M.Aim and Methods: Although the antimicrobial activity of extracts from several mushroom species has been reported, studies with the individual compounds present in that extracts are scarce. Herein, the antimicrobial activity of different phenolic compounds identified and quantified in mushroom species from all over the world was evaluated. Furthermore, a structure-activity relationship (SAR) analysis and molecular docking studies were performed, in order to provide insights into the mechanism of action of potential antimicrobial drugs for resistant micro-organisms. Results: 2,4-Dihydroxybenzoic and protocatechuic acids were the phenolic compounds with higher activity against the majority of Gram-negative and Gram-positive bacteria. Furthermore, phenolic compounds inhibited more MRSA than methicillin-susceptible Staphylococcus aureus. MRSA was inhibited by 2,4-dihydroxybenzoic, vanillic, syringic (MICs = 0.5 mg ml(-1)) and p-coumaric (MIC = 1 mg ml(-1)) acids, while these compounds at the same concentrations had no inhibitory effects against methicillin-susceptible Staph. aureus. Conclusions: The presence of carboxylic acid (COOH), two hydroxyl (OH) groups in para and ortho positions of the benzene ring and also a methoxyl (OCH3) group in the meta position seems to be important for anti-MRSA activity. Significance and Impact of the Study: Phenolic compounds could be used as antimicrobial agents, namely against some micro-organisms resistant to commercial antibiotics.
- Docking studies in target proteins involved in antibacterial action mechanisms: Extending the knowledge on standard antibiotics to antimicrobial mushroom compoundsPublication . Alves, Maria José; Froufe, Hugo J. C.; Costa, Ana F. T.; Santos, Anabela F.; Oliveira, Liliana G.; Osório, Sara R. M.; Abreu, Rui M. V.; Pintado, Manuela; Ferreira, Isabel C. F. R.In the present work, the knowledge on target proteins of standard antibiotics was extended to antimicrobial mushroom compounds. Docking studies were performed for 34 compounds in order to evaluate their affinity to bacterial proteins that are known targets for some antibiotics with different mechanism of action: inhibitors of cell wall synthesis, inhibitors of protein synthesis, inhibitors of nucleic acids synthesis and antimetabolites. After validation of the molecular docking approach, virtual screening of all the compounds was performed against penicillin binding protein 1a (PBP1a), alanine racemase (Alr), D-alanyl-D-alanine synthetase (Ddl), isoleucyl-tRNA sinthetase (IARS), DNA gyrase subunit B, topoisomerase IV (TopoIV), dihydropteroate synthetase (DHPS) and dihydrofolate reductase (DHFR) using AutoDock4. Overall, it seems that for the selected mushroom compounds (namely, enokipodins, ganomycins and austrocortiluteins) the main mechanism of the action is the inhibition of cell wall synthesis, being Alr and Ddl probable protein targets.
- Extraction of bioactive compounds from plants as promising agentes against SARS-CoV-2Publication . Pedrosa, Mariana C.; Rodrigues, Cláudia; Heleno, Sandrina; Carocho, Márcio; Abreu, Rui M. V.; Ribeiro, Tânia; Machado, Manuela; Pinto, Miguel Marques; Simas, Pedro; Pintado, Manuela; Barros, LillianBackground: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a pathogenic virus with high transmissibility and infectivity, which began to spread across the globe in late 2019, which soon became the COVID-19 pandemic, causing social and economic impacts. In response to this situation, the scientific community started the development of effective substances against this virus. Bioactive molecules present in plants, mainly phenolic compounds, are promising alternatives to combat pathological disorders. Therefore, the objective of this work was to use the aqueous extract of a mountain plant as an antiviral substance to neutralize COVID-19. Materials/Methods: The mountain plant extract was obtained by dynamic maceration in water for 1 hour (twice). After obtaining the extracts, they were evaluated for their phenolic profile by high performance liquid chromatography coupled to a diode array detector and a mass spectrometer detector (HPLC-DAD-MS). Cytotoxicity was determined by the sulphorhodamine B assay in Vero cells, as well as the evaluation of the antiviral activity. Results: Regarding the phenolic profile, the main compounds found were trigalloyl-HHDPglucoside; pentagalloyl glucose, quercetin 3-0-glucuronide and quercetin O-hexoside. The GI50 (concentration able to inhibit 50% of cell proliferation) and the MNCC (maximum concentration without toxicity) were between 100 and 180.3 µg/rnL and between 85 and 120 µg/rnL, respectively. The MNCC value was obtained considering the concentration that allowed 90% of cell proliferation of Vero cells. In relation to the viral activity screening, the results achieved for the viral titre were between 5000 and 9000 PFU/mL, while for the antiviral activity ranged between 0.5 and 3.0 Mv, being the percentage of reduction in a range of 85-95 %. Conclusion: The mountain plant extracts showed in its composition bioactive compounds and consistent results of antiviral activity. Moreover, it presents itself as a potential substance for protection applications against the COVID-19 virus. However, further studies in specific products are required for validation and implementation.