Bioactivities from marine algae of the genus Gracilaria de Almeida, Cynthia Layse F; Falcão, Heloina de S; Lima, Gedson R de M ...
International Journal of Molecular Sciences,
07/2011, Volume:
12, Issue:
7
Journal Article, Book Review
Peer reviewed
Open access
Seaweeds are an important source of bioactive metabolites for the pharmaceutical industry in drug development. Many of these compounds are used to treat diseases like cancer, acquired ...immune-deficiency syndrome (AIDS), inflammation, pain, arthritis, as well as viral, bacterial, and fungal infections. This paper offers a survey of the literature for Gracilaria algae extracts with biological activity, and identifies avenues for future research. Nineteen species of this genus that were tested for antibacterial, antiviral, antifungal, antihypertensive, cytotoxic, spermicidal, embriotoxic, and anti-inflammatory activities are cited from the 121 references consulted.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Aims
This study evaluated the antifungal, antibiofilm and molecular docking of 2‐chloro‐N‐phenylacetamide against clinical isolates of Candida tropicalis and Candida parapsilosis.
Methods and results
...Minimum inhibitory concentration (MIC) of the test drugs was determined by microdilution. A1Cl obtained MIC values ranging from 16 and 256 μg/ml. Fluconazole MIC ranging from 16 and 512 μg/ml. MIC of A1Cl showed fungicide activity, emphasizing the solid antifungal potential of this drug. An association study was performed with A1Cl and fluconazole (checkerboard), revealing indifference by decreasing. Thus, we conducted this study using A1Cl isolated. In the micromorphological assay, the test drugs reduced the production of virulence structures compared to the control (concentration‐dependent effect). A1Cl inhibited in vitro biofilm formation at all concentrations tested (1/4MIC to 8 × MIC) (p < 0.05) and reduced mature biofilm biomass (p < 0.05) against C. tropicalis and C. parapsilosis. In the ex vivo biofilm susceptibility testing (human nails fragments), A1Cl inhibited biofilm formation and reduced mature biofilm biomass (p < 0.05) more than 50% at MIC. Fluconazole had a similar effect at 4 × MIC. In silico studies suggest that the mechanism of antifungal activity of A1Cl involves the inhibition of the enzyme dihydrofolate reductase (DHFR) rather than geranylgeranyltransferase‐I.
Conclusions
The results suggest that A1Cl is a promising antifungal agent. Furthermore, this activity is related to attenuation of expression of virulence factors and antibiofilm effects against C. tropicalis and C. parapsilosis.
Significance and impact of the study
Our study provides the first evidence that A1Cl, a novel synthetic drug, has fungicidal effects against C. tropicalis and C. parapsilosis. Furthermore, in vitro and ex vivo biofilms assays have demonstrated the potential antibiofilm of A1Cl. The mechanism of action involves inhibiting the enzyme DHFR, which was supported by in silico analyses. Therefore, this potential can be explored as a therapeutic alternative for onychomycosis and, at the same time, contribute to decreasing the resistance of clinical isolates of C. tropicalis and C. parapsilosis.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Klebsiella pneumoniae is a species of Gram-negative bacteria related to a wide range of infections and high rates of drug resistance. The combined use of antibacterial agents is one of the strategies ...that has been analyzed in recent years as part of the alternatives in the treatment of drug-resistant infections. Recently, the antibacterial activity of of 2-chloro-N-(4-fluoro-3-nitrophenyl)acetamide has been demonstrated against K. pneumoniae, also indicating that this acetamide did not show significant cytotoxic potential in preliminary tests. Thus, it becomes an interesting substance for future studies that explore its antimicrobial capacity, including investigating its association with antibacterial drugs. Based on this, this research aimed to analyze the effects of the association of 2-chloro-N-(4-fluoro-3-nitrophenyl)acetamide (CFA) with ciprofloxacin, cefepime, ceftazidime, meropenem and imipenem against K. pneumoniae strains. The results showed additivity when the substance was combined with ciprofloxacin and cefepime, indifference when associated with ceftazidime and synergistic effect when combined with meropenem and imipenem. Thus, the acetamide was able to optimize the effects of antibacterial drugs, reducing the concentrations necessary to cause bacterial death. These data indicate a potential future clinical use of these combinations, and further studies are needed to analyze this viability.
Abstract Aspergillus genus causes many diseases, and the species Aspergillus flavus is highly virulent. Treatment of aspergillosis involves azole derivatives such as voriconazole and polyenes such as ...amphotericin B. Due to an increase in fungal resistance, treatments are now less effective; the search for new compounds with promising antifungal activity has gained importance. The aims of this study were to evaluate the effects of the synthetic amide 2-chloro-N-phenylacetamide (A1Cl) against strains of Aspergillus flavus and to elucidate its mechanism of action. Thus, the minimum inhibitory concentration, minimum fungicidal concentration, conidial germination, associations with antifungal agents, cell wall activities, membrane activities and molecular docking were evaluated. A1Cl presented antifungal activity against Aspergillus flavus strains with a minimum inhibitory concentration of between 16 and 256 μg/mL and a minimum fungicidal concentration between 32 and 512 μg/mL. The minimum inhibitory concentration of A1Cl also inhibited conidial germination, but when associated with amphotericin B and voriconazole, it promoted antagonistic effects. Binding to ergosterol on the fungal plasma membrane is the likely mechanism of action, along with possible inhibition of DNA synthesis through the inhibition of thymidylate synthase. It is concluded that the amide 2-chloro-N-phenylacetamide has promising antifungal potential.
We synthesized the mesoionic compound 2-(4-chlorophenyl)-3-methyl-4-(4-methylphenyl)-1,3-thiazole-5-thiolate and measured its refractive and absorptive nonlinear optical response in different ...temporal and spectral regimes. The experiments were performed by using the Z-scan technique with two pulsed light sources: the second harmonic (at 532 nm) of a mode-locked and Q-switched Nd–YAG laser (100 ps, 10 Hz) and a Ti: Sapphire laser system (100 fs, 1 kHz) operating at 800 nm. The observation and characterization of nonlinear refraction, two- and three-photon absorption, and excited state absorption of the mesoionic compound dissolved in dimethyl sulfoxide, in different concentrations, are presented and discussed with basis on the population redistribution in a three-energy-level model that allows the determination of the parameters which characterize the nonlinear response.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
This work aims to investigate the energy-related characteristics of apple bagasse, orange bagasse and cashew-apple bagasse to identify their potential as bioenergy feedstocks. For this, a detailed ...characterization was performed, including proximate analysis, ultimate analysis, atomic molar ratio, heating values, chemical composition, bulk density, bioenergy density, fuel-value-index (FVI), fossil fuel equivalence and potential CO2 retention. Proximate composition revealed moisture, volatile matter, fixed carbon and ash contents in the range of 7.8-9.3%, 67.1-74.2%, 16.2-22.0% and 1.6-5.7%, respectively. Typical values for carbon (44.8-49.9 wt.%), hydrogen (5.5-6.6 wt.%) and oxygen (40.1-44.2 wt.%), with low sulfur (< 0.1 wt.%) and nitrogen (< 2.7 wt.%) contents were found. In regard to bulk density (237.7-554 kg m−3) and bioenergy density (3.93-10.1 GJ m−3), juice processing residues have substantial values when compared with well-known lignocellulosic residues. Recoverable energy potential from the juice processing residues varied from 15.24 to 17.03 MJ kg−1. From FVI analysis, apple bagasse is expected to be more suitable for thermochemical processing. Orange bagasse, on the other hand, has the highest equivalent in fossil fuel volume. Consequently, its use as solid fuel may lead to a decrease in CO2 emissions from reference fuels.
This study describes a virtual screening performed for two series of selenides (28 compounds), derived from N-phenylacetamides chlorides and 7-chloro-quinoline, to determine their potential for ...leishmanicidal activity against Leishmania amazonensis and Leishmania donovani. Seven compounds were predicted as potential leishmanicides; therefore, they were synthesized from elemental selenium, as a precursor for the production of NaHSe, and subsequent reactions with 4,7-dichloro-quinoline and N-phenylacetamides chlorides were performed. The compounds were characterized by infrared (IR), 1H and 13C nuclear magnetic resonance (NMR), and sent for in vitro cytotoxicity tests against L. amazonensis and were found to be active and selective, and two compounds presented half-maximal inhibitory concentrations (IC50) of 5.67 and 10.81 µg mL-1. They also presented good interaction energies in the docking study, suggesting that may exert their effects by inhibiting the N-myristoyltransferase and O-acetylserine sulfhydrylase enzymes in parasites.
Nine new compounds derived from selenoglycolic acid were synthesized, and their structures were fully characterized by elemental analysis, infrared (IR), 1H and 13C nuclear magnetic resonance (NMR). ...The compounds were evaluated in an in silico study and showed strong to moderate antibacterial activity against several strains of Staphylococcus aureus. In particular, three compounds exhibited excellent antibacterial activity, with minimum inhibitory concentrations (MICs) between 16 and 64 µg mL-1. Furthermore, two of the nine compounds showed antifungal activity, with MIC of 1024 and 512 µg mL-1. In silico studies of the parameters of Lipinski's rule of five indicate that these compounds have potential to be new drug candidates.
A series of fifteen new piperine-derived diesters was synthesized through the substitution reaction between the salt of piperic acid, obtained through piperine basic hydrolysis, with the ...δ-chloro-esters, obtained through the cleavage of tetrahydrofuran (THF) with acyl chlorides in the presence of ZnCl2. The final compounds were obtained with yields ranging from 50 to 84% and were characterized by infrared (IR) and 1H and 13C nuclear magnetic resonance spectroscopy (NMR). The new compounds were evaluated in silico in regard to their ADME (absorption, distribution, metabolism, and excretion) properties, and in vitro for their antimicrobial activity against bacteria strains (Staphylococcus aureus and Pseudomonas aeruginosas), yeast fungi (Candida albicans and C. tropicalis) and filamentous fungi (Aspergillus fumigatus, A. flavus and A. niger). The results from the in silico studies of Lipinski’s rule of five showed that most compounds present good pharmacological possibilities, and the results from in vitro antimicrobial activity showed that 8 of the 15 synthesized compounds displayed antimicrobial activity, inhibiting the growth of 40-80% of tested strains, with a minimum inhibitory concentration (MIC) interval ranging from 1024 to 256 µg mL−1.
Piperine, previously extracted from black pepper (Piper nigrum L.), was used as a precursor for the synthesis of twelve new diester derivatives. The final products were obtained through the ...bimolecular nucleophilic substitution reaction (SN2) of the alkyl 2-chloroacetates and the salt of piperic acid, obtained from the basic hydrolysis of piperine. The compounds were synthesized with yields of 55-84% and characterized by infrared spectroscopy and 1H and 13C nuclear magnetic resonance. The evaluation of the compounds’ potential as new drug candidates was done through an in silico study of ADME properties (absorption, distribution, metabolization and excretion) and evaluation of antimicrobial activity against bacterial strains (Staphylococcus aureus and Pseudomonas aeruginosa), yeasts (Candida albicans and Candida tropicalis) and filamentous fungi (Aspergillus fumigatus, Aspergillus flavus and Aspergillus niger). The in silico study showed that the compounds were good drug candidates and antimicrobial evaluation demonstrated that 9 of the 12 compounds exhibited a minimum inhibitory concentration (MIC) ranging 1024-256 μg mL-1.
PDF
