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1.
PLoS One ; 15(8): e0235723, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797045

RESUMO

Mixtures of drugs often have greater therapeutic value than any of their constituent drugs alone, and such combination therapies are widely used to treat diseases such as cancer, malaria, and viral infections. However, developing useful drug mixtures is challenging due to complex interactions between drugs. Natural substances can be fruitful sources of useful drug mixtures because secondary metabolites produced by living organisms do not often act in isolation in vivo. In order to facilitate the study of interactions within natural substances, a new analytical method to quantify interactions using data generated in the process of bioassay-guided fractionation is presented here: the extract fractional inhibitory concentration index (EFICI). The EFICI method uses the framework of Loewe additivity to calculate fractional inhibitory concentration values by which interactions can be determined for any combination of fractions that make up a parent extract. The EFICI method was applied to data on the bioassay-guided fractionation of Lechea mucronata and Schinus terebinthifolia for growth inhibition of the pathogenic bacterium Acinetobacter baumannii. The L. mucronata extract contained synergistic interactions (EFICI = 0.4181) and the S. terebinthifolia extract was non-interactive overall (EFICI = 0.9129). Quantifying interactions in the bioassay-guided fractionation of natural substances does not require additional experiments and can be useful to guide the experimental process and to support the development of standardized extracts as botanical drugs.


Assuntos
Antibacterianos/farmacologia , Produtos Biológicos/farmacologia , Extratos Vegetais/farmacologia , Infecções por Acinetobacter/tratamento farmacológico , Acinetobacter baumannii/efeitos dos fármacos , Anacardiaceae/química , Antibacterianos/isolamento & purificação , Produtos Biológicos/isolamento & purificação , Fracionamento Químico , Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos/métodos , Sinergismo Farmacológico , Humanos , Extratos Vegetais/isolamento & purificação
2.
J Chromatogr A ; 1626: 461364, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797843

RESUMO

A new type of restricted access media-imprinted nanomaterials (RAM-MIPs) were successfully prepared on the surface of metal-organic framework by reversible addition fragmentation chain transfer polymerization technology. Then it was applied as a dispersed solid phase extraction (DSPE) material in analysis of fluoroquinolones (ofloxacin, pefloxacin, norfloxacin, enrofloxacin and gatifloxacin) in untreated milk and river water by HPLC-UV detection. The resulted material has a good binding amounts (60.81 mg g-1), rapid binding kinetic (15 min) and satisfactory selectivity as well as has a good ability to eliminate matrix interference. Several major factors affecting DSPE efficiency, pH of sample solution, dosage of RAM-MIPs, adsorption time and volume ratios of elution solvent were primarily optimized. In optimization conditions, RAM-MIPs-DSPE was combined with HPLC-UV to enrich fluoroquinolones in untreated milk and river water, achieving satisfactory linear correlation (R2 > 0.9988), good limits of detection (LOD, 1.02-3.15 µg L-1 for milk and 0.93-2.87 µg L-1 for river water) and better recoveries (80.7-103.5% and 85.1-105.9% with relative standard deviation (RSD) of not higher than 5.3% and 4.7% for milk and river water samples, respectively). The research results illustrate that it provides a simple and efficient method for the direct detection of FQs in complex samples.


Assuntos
Antibacterianos/análise , Fluoroquinolonas/análise , Estruturas Metalorgânicas/química , Leite/química , Nanoestruturas/química , Rios/química , Extração em Fase Sólida/métodos , Adsorção , Animais , Antibacterianos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Fluoroquinolonas/isolamento & purificação , Impressão Molecular , Polimerização
3.
J Med Microbiol ; 69(8): 1040-1048, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32692643

RESUMO

Given the increased reporting of multi-resistant bacteria and the shortage of newly approved medicines, researchers have been looking towards extreme and unusual environments as a new source of antibiotics. Streptomyces currently provides many of the world's clinical antibiotics, so it comes as no surprise that these bacteria have recently been isolated from traditional medicine. Given the wide array of traditional medicines, it is hoped that these discoveries can provide the much sought after core structure diversity that will be required of a new generation of antibiotics. This review discusses the contribution of Streptomyces to antibiotics and the potential of newly discovered species in traditional medicine. We also explore how knowledge of traditional medicines can aid current initiatives in sourcing new and chemically diverse antibiotics.


Assuntos
Antibacterianos/isolamento & purificação , Descoberta de Drogas/tendências , Microbiologia do Solo , Streptomyces/metabolismo , Animais , Antibacterianos/biossíntese , Cavernas/química , Invertebrados/química , Medicina Tradicional , Peptídeo Sintases/metabolismo , Plantas Medicinais/química , Policetídeo Sintases/metabolismo , Poríferos/química , Streptomyces/química , Streptomyces/enzimologia
4.
Food Chem ; 332: 127427, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32619936

RESUMO

A magnetic porous organic framework (M-POF) was rationally designed and served as a sorbent for magnetic solid-phase extraction of six nitroimidazoles from chicken meat prior to their assay by high-performance liquid chromatography with diode array detection. The M-POF exhibited good magnetic responsiveness and outstanding affinity to nitroimidazoles with large adsorption capacity up to 36 mg g-1. Under optimal conditions, the developed method offered good linearity (r greater than 0.992) in the range of 1.5-100.0 ng g-1, low limits of detection (S/N = 3) of 0.5-0.8 ng g-1, low limits of quantification of 1.5-2.5 ng g-1 and high enrichment factors of 80-175 for the nitroimidazoles. The method was successfully applied to analyze nitroimidazoles in chicken meat. The recoveries were 80.2-118% with relative standard deviations lower than 12%. The adsorption mechanism was further explored and the results showed that the M-POF exhibited adsorption potential for compounds with strong polar interactions.


Assuntos
Antibacterianos/isolamento & purificação , Contaminação de Alimentos/análise , Magnetismo/métodos , Carne/análise , Estruturas Metalorgânicas/química , Nitroimidazóis/isolamento & purificação , Extração em Fase Sólida/métodos , Adsorção , Animais , Antibacterianos/análise , Bioensaio , Galinhas , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Magnetismo/instrumentação , Músculo Esquelético/química , Nitroimidazóis/análise , Porosidade , Extração em Fase Sólida/instrumentação
5.
Proc Natl Acad Sci U S A ; 117(32): 19168-19177, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32719135

RESUMO

The emergence of superbugs developing resistance to antibiotics and the resurgence of microbial infections have led scientists to start an antimicrobial arms race. In this context, we have previously identified an active RiPP, the Ruminococcin C1, naturally produced by Ruminococcus gnavus E1, a symbiont of the healthy human intestinal microbiota. This RiPP, subclassified as a sactipeptide, requires the host digestive system to become active against pathogenic Clostridia and multidrug-resistant strains. Here we report its unique compact structure on the basis of four intramolecular thioether bridges with reversed stereochemistry introduced posttranslationally by a specific radical-SAM sactisynthase. This structure confers to the Ruminococcin C1 important clinical properties including stability to digestive conditions and physicochemical treatments, a higher affinity for bacteria than simulated intestinal epithelium, a valuable activity at therapeutic doses on a range of clinical pathogens, mediated by energy resources disruption, and finally safety for human gut tissues.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Clostridiales/química , Peptídeos/química , Peptídeos/farmacologia , Antibacterianos/isolamento & purificação , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Humanos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/microbiologia , Peptídeos/isolamento & purificação
6.
Int J Food Microbiol ; 331: 108732, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-32521374

RESUMO

The present study aimed to evaluate the anti-quorum sensing (anti-QS) and anti-proteolytic potentials of tarragon essential oil (TEO) and its major compounds against food-associated Pseudomonas spp. The activities were verified by in vitro, in silico and in situ approaches. In this work, methyl eugenol (ME)- and ß-phellandrene (ß-PH)-rich TEO was investigated. TEO at subMIC increased the percentage of saturated fatty acids in the bacterial membranes (from 7 to 22%) and exhibited anti-quorum sensing via decreasing the efficiency of QS autoinducer synthesis [3-oxo-C12-HSL (from 2.028 µg/mL to

Assuntos
Artemisia/química , Óleos Voláteis/farmacologia , Proteólise/efeitos dos fármacos , Pseudomonas/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , 4-Butirolactona/análogos & derivados , 4-Butirolactona/isolamento & purificação , 4-Butirolactona/farmacologia , Animais , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Simulação por Computador , Peixes/microbiologia , Homosserina/análogos & derivados , Homosserina/isolamento & purificação , Homosserina/farmacologia , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Pseudomonas/isolamento & purificação
7.
J Chromatogr A ; 1623: 461175, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505279

RESUMO

An ionic liquid hybrid zwitterionic polymer capillary microextraction (CME) column was prepared for the biomimetic enrichment of glycopeptides by one-step copolymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 1-butyl-3-vinylimidazolium bromide, in the presence of crosslinker trimethylolpropane trimethacrylate (TMA). The resultant monolith was characterized by scanning electron microscopy (SEM), fourier transform infrared (FT-IR) spectroscopy and pore size distribution measurement. Due to the incorporation of zwitterionic MPC owning a unique biomimic structure (i.e. hydrophilic cation/anion and hydrophobic long-alkyl chain), the monolithic column has large pore size and good biocompatibility, exhibiting high extraction efficiency, permeability and fast mass transfer to targets. Besides, the use of ionic liquids (ILs) as co-monomer in the polymerization endows the monolith with enhanced mechanical stability, uniformity and multiple interactions. The prepared column was successfully applied in CME coupled to capillary electrochromatography (CEC) for the efficient enrichment and separation of glycopeptide antibiotics in foodstuff. The method demonstrated a wide linear range (50.0-18000.0 µg L-1), low detection limits (5.0-10.0 µg L-1, S/N = 3) and satisfied recoveries (76.0-109.7%). This work shows the advantage of fine-tuning biomimetic monoliths in application-specific CME-CEC.


Assuntos
Antibacterianos/análise , Eletrocromatografia Capilar/métodos , Glicopeptídeos/análise , Líquidos Iônicos/química , Antibacterianos/isolamento & purificação , Materiais Biomiméticos , Fracionamento Químico , Análise de Alimentos/métodos , Glicopeptídeos/isolamento & purificação , Interações Hidrofóbicas e Hidrofílicas , Imidazóis/química , Metacrilatos/química , Microscopia Eletrônica de Varredura , Fosforilcolina/análogos & derivados , Fosforilcolina/química , Polimerização , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier , Compostos de Vinila/química
8.
Food Chem ; 329: 127162, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32492599

RESUMO

We report for the first time the use of biochar as a stabilizer for oil-in-water (o/w) Pickering emulsion. The emulsion is subsequently used to prepare tetracycline-imprinted biochar composite microspheres (MIPMs) with tailored sizes and good uniformity. The adsorption properties of tetracycline to the MIPMs were investigated using different adsorption experiments including adsorption kinetic experiment, equilibrium binding experiment, selectivity evaluation and competitive adsorption tests. The MIPMs were used as adsorbent for solid phase extraction (SPE) for the extraction of tetracycline present in drinking water, fish, and chicken samples. Under optimal conditions, the results showed good recovery yield ranging from ~73% to ~95% with a relative standard deviation (RSD) ranging from ~0.3% to ~8.4%, respectively.


Assuntos
Carvão Vegetal/química , Emulsões/química , Contaminação de Alimentos/análise , Extração em Fase Sólida/métodos , Tetraciclina/isolamento & purificação , Adsorção , Antibacterianos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Microesferas , Impressão Molecular/métodos , Extração em Fase Sólida/instrumentação , Poluentes Químicos da Água/isolamento & purificação
9.
PLoS One ; 15(6): e0234129, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32502188

RESUMO

Xenorhabdus and Photorhabdus, symbiotically associated with entomopathogenic nematodes (EPNs), produce a range of antimicrobial compounds. The objective of this study is to identify Xenorhabdus and Photorhabdus and their EPNs hosts, which were isolated from soil samples from Saraburi province, and study their antibacterial activity against 15 strains of drug-resistant bacteria. Fourteen isolates (6.1%), consisting of six Xenorhabdus isolates and eight Photorhabdus isolates, were obtained from 230 soil samples. Based on the BLASTN search incorporating the phylogenetic analysis of a partial recA gene, all six isolates of Xenorhabdus were found to be identical and closely related to X. stockiae. Five isolates of Photorhabdus were found to be identical and closely related to P. luminescens subsp. akhurstii. Two isolates of Photorhabdus were found to be identical and closely related to P. luminescens subsp. hainanensis. The remaining isolate of Photorhabdus was found to be identical to P. asymbiotica subsp. australis. The bacterial extracts from P. luminescens subsp. akhurstii showed strong inhibition the growth of S. aureus strain PB36 (MSRA) by disk diffusion, minimal inhibitory concentration, and minimal bactericidal concentration assay. The combination between each extract from Xenorhabdus/Photorhabdus and oxacillin or vancomycin against S. aureus strain PB36 (MRSA) exhibited no interaction on checkerboard assay. Moreover, killing curve assay of P. luminescens subsp. akhurstii extracts against S. aureus strain PB36 exhibited a steady reduction of 105 CFU/ml to 103 CFU/ml within 30 min. This study demonstrates that Xenorhabdus and Photorhabdus, showed antibacterial activity. This finding may be useful for further research on antibiotic production.


Assuntos
Antibacterianos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Nematoides/microbiologia , Photorhabdus/metabolismo , Xenorhabdus/metabolismo , Animais , Antibacterianos/isolamento & purificação , Testes de Sensibilidade Microbiana , Oxacilina/farmacologia , Photorhabdus/classificação , Photorhabdus/isolamento & purificação , Filogenia , Solo/parasitologia , Vancomicina/farmacologia , Xenorhabdus/classificação , Xenorhabdus/isolamento & purificação
10.
An Acad Bras Cienc ; 92(2): e20190615, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32556053

RESUMO

Hedychium coronarium J. Koening, belonging to Zingiberaceae family, is a perennial herb with fleshly aromatic rhizomes. There are no information about the antiplatelet properties of essential oils (EOs) from rhizomes (HCR) and leaves (HCL) of this herb, additionally, there are reports about the antibacterial activity of the Zingiberaceae species, however, no studies have been carried out in the Colombian Amazon Region. The EOs were characterized by GC-MS, the antiaggregant activity was assessed by ADP and Collagen as platelet agonist and the antibacterial activity against E. faecalis and S. aureus were evidenced by the determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). A high content of oxygenated monoterpenes were found in HCL essential oil (EO) and 20 compounds were identified in HCR EO. The HCL EO showed antiaggregant activity when collagen was used and HCR EO showed a concentration-dependent activity against ADP and collagen, meanwhile only the HCR EO showed antibacterial activity against E. faecalis and S. aureus.


Assuntos
Antibacterianos/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Óleos Voláteis/farmacologia , Inibidores da Agregação de Plaquetas/farmacologia , Rizoma/química , Staphylococcus aureus/efeitos dos fármacos , Zingiberaceae/química , Antibacterianos/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Testes de Sensibilidade Microbiana , Folhas de Planta/química , Inibidores da Agregação de Plaquetas/isolamento & purificação , Rizoma/classificação , Zingiberaceae/classificação
11.
Food Chem ; 326: 126969, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32438229

RESUMO

Biocompatible magnetic molecularly imprinted polymers (BMMIPs) were prepared with Zein for the first time, and were used to enrich tetracycline compounds selectively. Innovative combination of BMMIPs and electrochemistry to obtain lower detection line to satisfy industrial detection demands. Using Zein as the crosslinking agent, the polymers were synthesized on the surface of Fe3O4 particles. The scanning electron microscope, transmission electron microscope and X-ray diffraction technologies were used to characterize BMMIPs. Through optimization, BMMIPs attained large adsorption capacity (236.40 mg/g) with fast kinetics (40 min) and followed the Langmuir isotherm and pseudo-second-order kinetic models. BMMIPs had good recognition ability, the selective factors of oxytetracycline, chlortetracycline, doxycycline were 4.78, 4.23, and 3.39, respectively. Excellent linearity was attained in the range of 0.025-500 µg/mL, with low detection limits and low quantitation limits of 0.025 and 0.083 µg/mL. According to our exploring, BMMIPs was ideal materials for enrichment of tetracycline in complex biological samples.


Assuntos
Materiais Biocompatíveis/química , Contaminação de Alimentos/análise , Leite/química , Impressão Molecular/métodos , Tetraciclinas/análise , Adsorção , Animais , Antibacterianos/análise , Antibacterianos/química , Antibacterianos/isolamento & purificação , Técnicas Eletroquímicas , Análise de Alimentos/métodos , Limite de Detecção , Fenômenos Magnéticos , Nanopartículas de Magnetita/química , Polímeros/química , Tetraciclina/análise , Tetraciclina/química , Tetraciclina/isolamento & purificação , Tetraciclinas/química , Tetraciclinas/isolamento & purificação , Difração de Raios X , Zeína/química
12.
J Chromatogr A ; 1622: 461098, 2020 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-32376014

RESUMO

In the current study, a novel covalent organic frameworks COF-SCU1 incorporated electrospun nanofibers (PAN@COF-SCU1 nanofibers) was fabricated via a facile electrospinning method and utilized as adsorbent in pipette tip solid-phase extraction (PT-SPE) of tetracycline antibiotics (TCs) from foods. The prepared PAN@COF-SCU1 nanofibers possessed both of the unique characteristics of electrospun nanofibers and COFS-CU1, and thus improving the adsorption capacity of the electrospun nanofibers and preventing the problems of leakage and high pressure caused by directly using the nanosize COFs as adsorbent in PT-SPE. The experiments affected the adsorption and desorption efficiencies, such as the loading ratios of COFS-CU1 in nanofibers, the amount of nanofibers, the matrix pH and desorption solvent, were studied in detail. Eventually, a new pipette tip solid-phase extraction-high performance liquid chromatography (PT-SPE/HPLC) method was proposed for the analysis of three TCs from food. Satisfied linearity for TCs was obtained in the range of 4-70 ng mL-1. The limits of detection and quantification were ranged from 0.6 to 3 ng mL-1 and from 2 to 10 ng mL-1, respectively. The interday and intraday precisions (RSD) were all lower than 9%. The proposed PT-SPE/HPLC method was used to determine TCs residues in grass carp and duck samples for the first time. The results could not only explore the availability of PT-SPE in the extraction of TCs in food samples, but also broadened the potential applications of COFs in sample preparation.


Assuntos
Carpas , Patos , Análise de Alimentos , Estruturas Metalorgânicas , Nanofibras , Extração em Fase Sólida , Tetraciclinas , Adsorção , Animais , Antibacterianos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Análise de Alimentos/métodos , Estruturas Metalorgânicas/síntese química , Nanofibras/química , Tetraciclinas/isolamento & purificação
13.
World J Microbiol Biotechnol ; 36(5): 72, 2020 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-32363424

RESUMO

The bacteriocinogenic lactic acid bacterium Pediococcus pentosaceus LJR1 isolated from rumen liquor of goat had strong anti-bacterial activity toward Listeria monocytogenes in vitro. This antibacterial activity was lost on treatment with protease indicating that the bacteriocin is proteinaceous in nature. The bacteriocin LJR1 produced by P. pentosaceus was purified following a three step procedure consisting of ammonium sulphate precipitation, gel filtration chromatography and reverse phase-high performance liquid chromatography. The molecular weight of purified bacteriocin was determined to be 4.6 kDa using Tricine SDS-PAGE. Further, we found that the proteinaceous bacteriocin was stable at 100 °C as well as 121 °C for 30 min and 15 min respectively and also at different pH ranging from 4 to 10 when stored for 15 min at 37 °C. Its minimum inhibitory concentration for S. typhi MTCC134 and L. monocytogenes MTCC 1143 was 7.81 µg/ml and 15.63 µg/ml respectively. Scanning electron microscopy analysis of the surface of S. typhi treated with the bacteriocin showed the presence of craters; while in the case of treated L. monocytogenes blebs were observed. The addition of the bacteriocin to shrimp (white leg shrimp) has led to reduction of about 1 log units of L. monocytogenes on day 1 and maintained for 7 days on storage at 4 °C. It is clear that the purified bacteriocin has good potential as a bio preservative for application in food industry.


Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bacteriocinas/isolamento & purificação , Bacteriocinas/farmacologia , Conservação de Alimentos/métodos , Pediococcus pentosaceus/metabolismo , Penaeidae/microbiologia , Animais , Antibacterianos/química , Bacteriocinas/química , Bacteriocinas/genética , Microbiologia de Alimentos , Listeria monocytogenes/citologia , Listeria monocytogenes/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Peso Molecular , Pediocinas/genética , Pediococcus pentosaceus/genética , Salmonella typhi/citologia , Salmonella typhi/efeitos dos fármacos , Alimentos Marinhos/microbiologia
14.
Mar Drugs ; 18(4)2020 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-32344725

RESUMO

Sponge-associated fungi are attractive targets for the isolation of bioactive natural products with different pharmaceutical purposes. In this investigation, 20 fungi were isolated from 10 different sponge specimens. One isolate, the fungus Penicillium citrinum strain WK-P9, showed activity against Bacillus subtilis JH642 when cultivated in malt extract medium. One new and three known citrinin derivatives were isolated from the extract of this fungus. The structures were elucidated by 1D and 2D NMR spectroscopy, as well as LC-HRMS. Their antibacterial activity against a set of common human pathogenic bacteria and fungi was tested. Compound 2 showed moderate activity against Mycobacterium smegmatis ATCC607 with a minimum inhibitory concentration (MIC) of 32 µg/mL. Compound 4 exhibited moderate growth inhibition against Bacillus subtilis JH642, B. megaterium DSM32, and M. smegmatis ATCC607 with MICs of 16, 16, and 32 µg/mL, respectively. Furthermore, weak activities of 64 µg/mL against B. subtilis DSM10 and S. aureus ATCC25923 were observed for compound 4.


Assuntos
Antibacterianos/isolamento & purificação , Citrinina/isolamento & purificação , Penicillium/química , Poríferos/microbiologia , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Citrinina/química , Citrinina/farmacologia , Fungos/efeitos dos fármacos , Indonésia , Testes de Sensibilidade Microbiana , Penicillium/isolamento & purificação
15.
Zhongguo Zhong Yao Za Zhi ; 45(4): 896-898, 2020 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-32237491

RESUMO

A new isobenzoisofuran(1) has been isolated from the whole plant of Cassia pumila using various chromatographic techniques, including silica gel, Sephadex, MCI-gel resin, and RP-HPLC, and its structure was determined as 9-(2-hydroxyethyl)-2,2-dimethyl-2H-furo[3,4-g]chromen-6(8H)-one. This compound was also evaluated for its antibacterial activity. The results showed that it had prominent antibacterial activity with MIC_(90) value of(45.2±4.2) µg·mL~(-1) for methicillin resistant Staphylococcus aureus(MRSA) strain. This value was closed to that of levofloxacin [with MIC_(90) value(48.5±4.3) µg·mL~(-1)].


Assuntos
Antibacterianos/farmacologia , Benzofuranos/farmacologia , Cassia/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Antibacterianos/isolamento & purificação , Benzofuranos/isolamento & purificação , Levofloxacino , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Plantas Medicinais/química
16.
Chemosphere ; 253: 126728, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32298913

RESUMO

Nile perch wastewater was biodegraded using two Bacillus species to recover bioactive substances to enhance its reutilization value. The two Bacillus species successfully produced low-molecular-weight substances with a 47.8% degree of hydrolysis. The antioxidant activities of the Nile perch wastewater increased as the biodegradation proceeded, and the culture supernatant exhibited the highest DPPH (80.1%), ABTS (93.1%) and Fe2+ chelating (88.5%) antioxidant activities at 60 h. The antioxidant potential of the biodegraded Nile perch wastewater was found to be higher than those of other fish hydrolysates. Moreover, the biodegraded Nile perch wastewater exhibited effective antimicrobial activity against Vibrio vulnificus, exhibiting a minimal inhibitory concentration of 585 µg mL-1. Two-dimensional thin layer chromatography analysis revealed the specific amino acids responsible for the antioxidant activity, and molecular-weight cut-off ultrafiltration revealed that the <2-kDa fraction exhibited the highest antioxidant activity with the lowest IC50 values (0.43 and 0.22 mg mL-1 for DPPH and ABTS antioxidant activities, respectively). This is the first report of the reutilization of Nile perch wastewater as a natural antioxidant and antimicrobial ingredient for nutraceuticals.


Assuntos
Antibacterianos/isolamento & purificação , Antioxidantes/isolamento & purificação , Bacillus/metabolismo , Peptídeos/isolamento & purificação , Percas , Águas Residuárias/química , Aminoácidos/isolamento & purificação , Aminoácidos/farmacologia , Animais , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Biodegradação Ambiental , Compostos de Bifenilo/química , Quelantes/isolamento & purificação , Quelantes/farmacologia , Pesqueiros , Hidrólise , Peso Molecular , Peptídeos/farmacologia , Percas/crescimento & desenvolvimento , Picratos/química , Ultrafiltração , Vibrio vulnificus/efeitos dos fármacos
17.
PLoS One ; 15(4): e0231045, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32287274

RESUMO

A green synthesis approach was conducted to prepare amine-functionalized bio-graphene (AFBG) as an efficient and low cost adsorbent that can be obtained from agricultural wastes. In this study, bio-graphene was successfully used to remove Ciprofloxacin (CIP) from synthetic solutions. The efficacy of adsorbent as a function of operating variables (i.e. pH, time, AFBG dose and CIP concentration) was described by a polynomial model. A optimal99.3% experimental removal was achieved by adjusting the mixing time, AFBG dose, pH and CIP concentration to 58.16, 0.99, 7.47, and 52.9, respectively. Kinetic model revealed that CIP diffusion into the internal layers of AFBG controls the rate of the process. Furthermore, the sorption process was in monolayer with a maximum monolayer capacity of 172.6 mg/g. Adsorption also found to be favored under higher CIP concentrations. The thermodynamic parameters (ΔG°<0, ΔH°>0, and ΔS°>0) demonstrated that the process is endothermic and spontaneous in nature. The regeneration study showed that the AFBG could simply regenerated without significant lost in adsorption capacity.


Assuntos
Antibacterianos/isolamento & purificação , Ciprofloxacino/isolamento & purificação , Grafite , Purificação da Água/métodos , Adsorção , Biomassa , Grafite/síntese química , Águas Residuárias/química
18.
Electron. j. biotechnol ; 44: 41-46, Mar. 2020. tab, ilus
Artigo em Inglês | LILACS | ID: biblio-1087698

RESUMO

Background: The main objective of this study was to isolate fungi associated with Anthopleura xanthogrammica and measure their antimicrobial and enzymatic activities. A total of 93 fungal strains associated with A. xanthogrammica were isolated in this study, of which 32 isolates were identified using both morphological characteristics and internal transcribed spacer (ITS) sequence analysis. The antibacterial activities of 32 fungal isolates were tested against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Edwardsiella tarda, Vibrio harveyi, Fusarium oxysporum, and Pyricularia oryzae by agar diffusion assay. Extracellular hydrolytic enzyme activities of the fungal isolates were determined by agar diffusion assays. Enzyme activities were detected from clear halo size. Results: The isolated fungi belonged to 18 genera within 7 taxonomic orders of 1 phylum. The genera Aspergillaceae were the most diverse and common. The antimicrobial activities of 32 isolates were evaluated, and 19 (59.4%) of fungi isolate displayed unique antimicrobial activities. All fungal strains displayed at least one enzyme activity. The most common enzyme activities in the fungi isolates were amylase and protease, while the least common were pectinase and xylanase. Conclusions: This is first report on the sea anemone-derived fungi with antimicrobial and enzyme activities. Results indicated that sea anemone is a hot spot of fungal diversity and a rich resource of bioactive natural products.


Assuntos
Aspergillus/isolamento & purificação , Anêmonas-do-Mar/microbiologia , Antibacterianos/isolamento & purificação , Peptídeo Hidrolases/metabolismo , Filogenia , Poligalacturonase/metabolismo , Aspergillus/enzimologia , Aspergillus/genética , Bactérias/efeitos dos fármacos , DNA Espaçador Ribossômico , Biodiversidade , Fungos/isolamento & purificação , Fungos/genética , Amilases/metabolismo , Antibacterianos/farmacologia
19.
Environ Monit Assess ; 192(4): 244, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32198545

RESUMO

The information available on microalgae-sourced compounds, especially antibiotics and other bioactive compounds, and their potential commercial applications is still insufficient. In this study, antibacterial activity, metabolites, and molecular characterization of Phormidium autumnale, which was isolated from samples collected from different natural freshwater sources in Ankara, Turkey, were investigated. Sequencing results of 16s rDNA confirmed the molecular identification of P. autumnale by 99%. It was determined that the peak values of some phenolic compounds and cyclic peptides were consistent with the 1653-1389 cm-1 band regions in the FTIR spectra of the species. The antibacterial activities of P. autumnale cyanobacteria (CBA) extracts that were obtained by using different solvents were tested on Escherichia coli, Staphylococcus epidermidis, methicillin-resistant (MR) Staphylococcus aureus, Streptococcus agalactiae, and Enterococcus faecalis by using a disc diffusion method. Also, the minimum inhibition concentration (MIC) and antimicrobial indexes of all extracts were determined. It was found that P. autumnale methanol extracts showed antibacterial activity on all test bacteria, whereas acetone extracts showed effects only on E. coli. For the inhibition of MR S. aureus, the control methanol extract was found to give very similar results to those exhibited by the control antibiotics, and the antimicrobial index results were determined to be 58.7-67.5%. According to the results of the analysis of methanol extract, gentisic acid, vanillic acid, 4-hydroxybenzoic acid, p-coumaric acid, and catechin (especially phenolic compounds) were determined to be the active compounds. It can be concluded that P. autumnale is an alternative to current commercial applications as an antibacterial agent in phytotherapy.


Assuntos
Cianobactérias , Escherichia coli , Compostos Fitoquímicos , Staphylococcus aureus , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Cianobactérias/química , Cianobactérias/genética , Escherichia coli/efeitos dos fármacos , Água Doce , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Fitoterapia , Staphylococcus aureus/efeitos dos fármacos , Turquia
20.
PLoS One ; 15(3): e0229417, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32134941

RESUMO

Streptococcus pneumoniae infections are one of the major causes of morbility and mortality worldwide. Although vaccination and antibiotherapy constitute fundamental and complementary strategies against pneumococcal infections, they present some limitations including the increase in non-vaccine serotypes and the emergence of multidrug-resistances, respectively. Ribosomally-synthesized antimicrobial peptides (i.e. bacteriocins) produced by Lactic Acid Bacteria (LAB) may represent an alternative or complementary strategy to antibiotics for the control of pneumococal infections. We tested the antimicrobial activity of 37 bacteriocinogenic LAB, isolated from food and other sources, against clinical S. pneumoniae strains. Streptococcus infantarius subsp. infantarius LP90, isolated from Venezuelan water-buffalo milk, was selected because of its broad and strong anti-pneumococcal spectrum. The in vitro safety assessment of S. infantarius LP90 revealed that it may be considered avirulent. The analysis of a 19,539-bp cluster showed the presence of 29 putative open reading frames (ORFs), including the genes encoding 8 new class II-bacteriocins, as well as the proteins involved in their secretion, immunity and regulation. Transcriptional analyses evidenced that the induction factor (IF) structural gene, the bacteriocin/IF transporter genes, the bacteriocin structural genes and most of the bacteriocin immunity genes were transcribed. MALDI-TOF analyses of peptides purified using different multichromatographic procedures revealed that the dairy strain S. infantarius LP90 produces at least 6 bacteriocins, including infantaricin A1, a novel anti-pneumococcal two-peptide bacteriocin.


Assuntos
Antibacterianos/metabolismo , Bacteriocinas/genética , Bacteriocinas/metabolismo , Infecções Pneumocócicas/metabolismo , Streptococcus/efeitos dos fármacos , Streptococcus/isolamento & purificação , Sequência de Aminoácidos , Antibacterianos/administração & dosagem , Antibacterianos/isolamento & purificação , Bacteriocinas/administração & dosagem , Bacteriocinas/isolamento & purificação , Humanos , Infecções Pneumocócicas/genética , Infecções Pneumocócicas/microbiologia , Streptococcus/classificação
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