Objective: To establish the chemical profile, and to evaluate the antibacterial and modulatory activity of the ethanolic extracts of the stalk's inner bark and heartwood of Secondatia floribunda.Methods: Quantific...Objective: To establish the chemical profile, and to evaluate the antibacterial and modulatory activity of the ethanolic extracts of the stalk's inner bark and heartwood of Secondatia floribunda.Methods: Quantification of total plienols and flavonoids was determined by the FolinCiocalteu method and aluminum chloride, respectively. Phenolic compounds were identified and quantified by HPLC-DAD(High Performance Liquid ChromatographyDiodearray Detector) and the Infrared Spectroscopy was performed using the measure by Attenuated Total Reflectance with Fourier Transform(ATR-FTIR). Antibacterial assays for determination of the Minimum Inhibitory Concentration(MIC) and modification of aminoglycosides were performed by microdilution.Results: Infrared spectra showed similar characteristics, having among its main absorption bands hydroxyl group(OH). The antibacterial activity showed clinically significant results for the strains of Staphylococcus aureus and Escherichia coli. In modulation assay, synergic and antagonistic effect for both extracts was observed.Hearttwood extract in combination with antibiotics showed a significant MIC reduction at 19.8%(P<0.0001)-79.3%(P<0.01).Conclusions: This study is the first report of chemical and biological information of Secondatia floribunda suggesting that it is clinically relevant source of a new antibacterial therapy, especially due to the presence of significant levels of phenolic compounds.展开更多
Due to its high strength, high modulus, excellent clarity, good biodegradability and biocompatibility, poly(lactic acid)(PLA), a bio-based thermoplastic polyester, has evolved into a competitive commodity material wit...Due to its high strength, high modulus, excellent clarity, good biodegradability and biocompatibility, poly(lactic acid)(PLA), a bio-based thermoplastic polyester, has evolved into a competitive commodity material with potential to replace conventional petrochemical-based polymers. However, the wide applications of PLA have been hampered by its native drawbacks, such as low heat distortion temperature(HDT), inherent brittleness and relatively high cost. In recent years, researchers have devoted to breaking above-mentioned bottleneck and attempted to extend the application of PLA. This review will summarize recent work about the modification of PLA, especially focusing on enhancing HDT, toughening and reducing cost.展开更多
基金Brazilian institutions and research agencies FUNCAP,URCA,UFRPE,ICMBio,UFSM and FIOCRUZ
文摘Objective: To establish the chemical profile, and to evaluate the antibacterial and modulatory activity of the ethanolic extracts of the stalk's inner bark and heartwood of Secondatia floribunda.Methods: Quantification of total plienols and flavonoids was determined by the FolinCiocalteu method and aluminum chloride, respectively. Phenolic compounds were identified and quantified by HPLC-DAD(High Performance Liquid ChromatographyDiodearray Detector) and the Infrared Spectroscopy was performed using the measure by Attenuated Total Reflectance with Fourier Transform(ATR-FTIR). Antibacterial assays for determination of the Minimum Inhibitory Concentration(MIC) and modification of aminoglycosides were performed by microdilution.Results: Infrared spectra showed similar characteristics, having among its main absorption bands hydroxyl group(OH). The antibacterial activity showed clinically significant results for the strains of Staphylococcus aureus and Escherichia coli. In modulation assay, synergic and antagonistic effect for both extracts was observed.Hearttwood extract in combination with antibiotics showed a significant MIC reduction at 19.8%(P<0.0001)-79.3%(P<0.01).Conclusions: This study is the first report of chemical and biological information of Secondatia floribunda suggesting that it is clinically relevant source of a new antibacterial therapy, especially due to the presence of significant levels of phenolic compounds.
基金supported by the Science and Technology Service Network Initiative Project of Chinese Academy of Sciences (KFJ-EW-STS-077)
文摘Due to its high strength, high modulus, excellent clarity, good biodegradability and biocompatibility, poly(lactic acid)(PLA), a bio-based thermoplastic polyester, has evolved into a competitive commodity material with potential to replace conventional petrochemical-based polymers. However, the wide applications of PLA have been hampered by its native drawbacks, such as low heat distortion temperature(HDT), inherent brittleness and relatively high cost. In recent years, researchers have devoted to breaking above-mentioned bottleneck and attempted to extend the application of PLA. This review will summarize recent work about the modification of PLA, especially focusing on enhancing HDT, toughening and reducing cost.
