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1.
Naturwissenschaften ; 106(9-10): 51, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31455975

RESUMO

Endophytic actinomycetes, a prolific source of natural products, are well known for their diverse metabolic versatility, and their association with medicinal plants and antimicrobial potential are well worth exploring. We isolated and identified the Streptomyces cavourensis strain MH16 inhabiting the tree Millingtonia hortensis Linn. using phylogenetic analysis based on a 16S rRNA molecular approach. We used the disc diffusion method to evaluate the impact of differences in the compositions of the media on the production of secondary metabolites from strain MH16. The production of antimicrobial metabolites was determined by the observation of inhibition zones on intensive bands when using a TLC-bioautography assay. Biosynthesis of secondary metabolites was optimal when the strain MH16 was cultured in ISP-2 medium as depicted by a zone of inhibition. Strain MH16 effectively inhibited methicillin-resistant Staphylococcus aureus, Escherichia coli, Candida albicans, and other multi drug-resistant pathogens. The minimum inhibitory concentration of the antimicrobial metabolites was 25-100 µg mL-1. The study manifests the optimization and utilization of different fermentation media which best suits for increased production of the secondary metabolites from Streptomyces cavourensis. This research suggests that the antimicrobial metabolites of strain MH16 found in M. hortensis has great potential for the biodiscovery of new anti-infective drugs against a wide range of multidrug-resistant pathogens.


Assuntos
Peptídeos Catiônicos Antimicrobianos/biossíntese , Peptídeos Catiônicos Antimicrobianos/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Streptomyces/genética , Streptomyces/metabolismo , Bactérias/efeitos dos fármacos , Meios de Cultura/farmacologia , Fungos/efeitos dos fármacos , Lamiales/microbiologia , Testes de Sensibilidade Microbiana , RNA Ribossômico 16S/genética , Streptomyces/efeitos dos fármacos , Streptomyces/crescimento & desenvolvimento
2.
J Enzyme Inhib Med Chem ; 34(1): 1388-1399, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31392901

RESUMO

Fourteen novel dipeptide carboxamide derivatives bearing benzensulphonamoyl propanamide were synthesized and characterized using 1H NMR, 13C NMR, FTIR and MS spectroscopic techniques. In vivo antimalarial and in vitro antimicrobial studies were carried out on these synthesized compounds. Molecular docking, haematological analysis, liver and kidney function tests were also evaluated to assess the effect of the compounds on the organs. At 200 mg/kg body weight, 7i inhibited the multiplication of the parasite by 81.38% on day 12 of post-treatment exposure. This was comparable to the 82.34% reduction with artemisinin. The minimum inhibitory concentration (MIC) in µM ranged from 0.03 to 2.34 with 7h having MIC of 0.03 µM against Plasmodium falciparium. The in vitro antibacterial activity of the compounds against some clinically isolated bacteria strains showed varied activities with some of the new compounds showing better activities against the bacteria and the fungi more than the reference drug ciprofloxacin and fluconazole.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antimaláricos/química , Antimaláricos/farmacologia , Dipeptídeos/química , Dipeptídeos/farmacologia , Sulfonamidas/farmacologia , Animais , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Antimaláricos/síntese química , Bactérias/efeitos dos fármacos , Dipeptídeos/síntese química , Fungos/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Testes de Sensibilidade Parasitária , Plasmodium falciparum/efeitos dos fármacos , Ratos , Sulfonamidas/química
3.
J Enzyme Inhib Med Chem ; 34(1): 1226-1232, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31307248

RESUMO

Allosamidins come from the secondary metabolites of Streptomyces species, and they have the pseudotrisaccharide structures. Allosamidins are chitinase inhibitors that can be used to study the physiological effects of chitinases in a variety of organisms. They have the novel antiasthmatic activity and insecticidal/antifungal activities. Herein, the synthesis and activities of allosamidins were summarized and analyzed.


Assuntos
Acetilglucosamina/análogos & derivados , Antiasmáticos/farmacologia , Antifúngicos/farmacologia , Inseticidas/farmacologia , Trissacarídeos/farmacologia , Acetilglucosamina/química , Acetilglucosamina/isolamento & purificação , Acetilglucosamina/farmacologia , Animais , Antiasmáticos/química , Antiasmáticos/isolamento & purificação , Antifúngicos/química , Antifúngicos/isolamento & purificação , Asma/tratamento farmacológico , Fungos/efeitos dos fármacos , Humanos , Inseticidas/química , Inseticidas/isolamento & purificação , Conformação Molecular , Mariposas/efeitos dos fármacos , Streptomyces/química , Trissacarídeos/química , Trissacarídeos/isolamento & purificação
4.
J Microbiol Biotechnol ; 29(7): 1009-1013, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31288302

RESUMO

Polymeric nanoparticles are widely used for drug delivery due to their biodegradability property. Among the wide array of polymers, chitosan has received growing interest among researchers. It was widely used as a vehicle in polymeric nanoparticles for drug targeting. This review explored the current research on the antimicrobial activity of chitosan nanoparticles (ChNP) and the impact on the clinical applications. The antimicrobial activities of ChNP were widely reported against bacteria, fungi, yeasts and algae, in both in vivo and in vitro studies. For pharmaceutical applications, ChNP were used as antimicrobial coating for promoting wound healing, preventing infections and combating the rise of infectious disease. Besides, ChNP also exhibited significant inhibitory on foodborne microorganisms, particularly on fruits and vegetables. It is noteworthy that ChNP can be also applied to deliver antimicrobial drugs, which further enhance the efficiency and stability of the antimicrobial agent. The present review addresses the potential antimicrobial applications of ChNP from these few aspects.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Quitosana/química , Portadores de Fármacos/química , Fungos/efeitos dos fármacos , Nanopartículas/química , Materiais Biocompatíveis , Sistemas de Liberação de Medicamentos , Humanos , Nanotecnologia , Polímeros/química
5.
BMC Infect Dis ; 19(1): 603, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291896

RESUMO

BACKGROUND: This study aims to investigate the pathogen distribution and drug resistance in patients with acute cerebral infarction complicated with diabetes mellitus and nosocomial pulmonary infection. METHODS: From August 2015 to December 2017, 172 pathogenic bacterial strains from patients with acute cerebral infarction complicated with diabetes mellitus and nosocomial pulmonary infection in our hospital were identified, and the drug sensitivity was analyzed. RESULTS: Among these 172 strains of pathogenic bacteria, gram negative bacteria was the main cause of pulmonary infection in hospitalized patients with acute cerebral infarction, accounting for 75.6% of all pathogens. Furthermore, 80% of diabetic patients with cerebral infarction had lung infection induced by gram negative bacteria, which was significantly higher than that in non-diabetic patients (72.2%). Moreover, the drug resistance rate in the diabetic group (68.3%) was significantly higher than that in the non-diabetic group (54.3%). Gram positive bacteria accounted for 19.1% of all pathogenic bacteria. The infection rate of gram-positive bacteria in diabetic patients with cerebral infarction was 14.7%, which was lower than that in the non-diabetic group (22.6%). The drug-resistance rate was higher in the diabetic group (45.5%) than in the non-diabetic group (28.2%). Furthermore, the fungal infection rate in patients with lung infection in these two groups was 5.3 and 5.2%, respectively, and fungi presented with high sensitivity to commonly used antifungal agents. CONCLUSION: In patients with acute cerebral infarction complicated with diabetes mellitus and nosocomial pulmonary infection, the majority of pathogens are multidrug-resistant gram negative bacilli. Pathogen culture should be conducted as soon as possible before using antibiotics, and antimicrobial agents should be reasonably used according to drug sensitivity test results.


Assuntos
Infarto Cerebral/complicações , Infecção Hospitalar/microbiologia , Complicações do Diabetes/microbiologia , Resistência Microbiana a Medicamentos , Pneumonia/microbiologia , Doença Aguda , Anti-Infecciosos/farmacologia , Anti-Infecciosos/uso terapêutico , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Infarto Cerebral/tratamento farmacológico , Infarto Cerebral/microbiologia , Infecção Hospitalar/tratamento farmacológico , Complicações do Diabetes/tratamento farmacológico , Feminino , Fungos/classificação , Fungos/efeitos dos fármacos , Fungos/isolamento & purificação , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pneumonia/tratamento farmacológico
6.
J Sci Food Agric ; 99(13): 6032-6041, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31226218

RESUMO

BACKGROUND: In order to inhibit microorganisms and improve storage quality of fresh-cut cucumber, fresh-cut cucumber was treated by carbon dots (CDs) from kelp/chitosan (CH) coating solution with CD concentrations of 0%, 1.5%, 3% and 4.5% and then packaged as well as stored at 4 °C for 15 days. The effect of CDs/CH coating on microorganisms and the quality of modified-atmosphere-packaged fresh-cut cucumber during storage were investigated. RESULTS: The CDs was monodispersed spherical morphology with size distribution of 0.54-0.83 nm. Interaction of CDs and CH had the generation of strong hydrogen bond. Inhibition zone diameters of CDs/CH coating against Staphylococcus aureus and Escherichia coli were enhanced with the increase of CD concentrations. Moreover, CDs/CH coating inhibited the growth of total number of colonies, mold, and yeast in modified-atmosphere-packaged fresh-cut cucumber during storage. A coating of 4.5% CDs/CH effectively reduced the losses of weight, firmness, and total soluble solids, the degradation of ascorbic acid content and flavor, and inhibited peroxidases activity, as well as decreased water mobility in fresh-cut cucumber during storage. CONCLUSION: The results indicated that a CDs/CH coating was helpful for inhibiting microorganisms and improving storage quality, and could be an effective method to prolong shelf life of fresh-cut cucumber. © 2019 Society of Chemical Industry.


Assuntos
Carbono/farmacologia , Quitosana/farmacologia , Cucumis sativus/efeitos dos fármacos , Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Carbono/química , Quitosana/química , Cucumis sativus/microbiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Embalagem de Alimentos , Conservação de Alimentos/instrumentação , Conservantes de Alimentos/química , Armazenamento de Alimentos , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Humanos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Paladar
7.
Naturwissenschaften ; 106(7-8): 37, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31209578

RESUMO

Millipedes use an array of chemical compounds to defend themselves from predator attack. These chemical substances can have additional roles, i.e. defence against various pathogens. We evaluated the efficacy of the defensive secretion of Apfelbeckia insculpta (L. Koch, 1867) against bacteria, yeasts, and filamentous fungi. The tested secretion consisted of two compounds, p-cresol and phenol, and showed antibacterial, antibiofilm, and antifungal potential against all selected microorganisms. The most sensitive bacterium in our study was Pseudomonas aeruginosa, while the tested defensive secretion manifested the lowest activity against Escherichia coli. The defensive secretion of A. insculpta also showed an ability, albeit mild, to suppress biofilm formation by P. aeruginosa. Among the tested yeasts, Candida albicans and C. krusei were the most susceptible and most resistant species, respectively. Finally, the concentration of extracts obtained from the tested defensive secretion needed to achieve an antifungal effect was lowest in the case of Cladosporium cladosporioides. Fusarium verticillioides and Penicillium rubens were the micromycetes most resistant to the tested secretion. Our results indicate that antibacterial activity of the defensive secretion of A. insculpta is similar to or slightly weaker than that of streptomycin, while comparison with antimycotics showed that the tested millipede secretion has stronger activity than fluconazole, but weaker activity than nystatin and ketoconazole. The present study corroborates previous findings indicating that the defensive secretions of millipedes can have different roles apart from antipredator protection and are effective against pathogenic microorganisms.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Artrópodes/química , Bactérias/efeitos dos fármacos , Fungos/efeitos dos fármacos , Fenóis/química , Animais , Anti-Infecciosos/isolamento & purificação , Península Balcânica , Testes de Sensibilidade Microbiana
8.
BMC Complement Altern Med ; 19(1): 146, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227024

RESUMO

BACKGROUND: There is increasing interest in the pharmaceutical and food industries to substitute synthetic chemicals with naturally occurring compounds possessing bioactive properties. Plants are valuable sources of bioactive compounds. The present study investigates the chemical composition and antioxidant, antimicrobial, and anticancer activities of ethanolic extracts (EEs) and essential oils (EOs) from two species in the Lamiaceae family, Ocimum basilicum L. and Thymus algeriensis Boiss. & Reut., cultivated in the Algerian Saharan Atlas. METHODS: The total flavonoid contents of the plants' ethanolic extracts were determined by the aluminium chloride method, while the total phenols were determined using the Folin-Ciocalteu method. Essential oils were obtained by hydrodistillation of the aerial parts of the plants and were analysed by GC-MS. The free radical-scavenging ability and antioxidant potential of the plants' EEs and EOs were probed using the 2, 2-diphenyl-picrylhydrazyl radical-scavenging, ABTS radical-scavenging, ferric-reducing power and phosphomolybdenum assays. The antimicrobial activities were evaluated against several pathogens characteristic of gram-negative bacteria (three species), gram-positive bacteria (three species) and fungi (two species). The microdilution method was used to estimate the minimum inhibitory concentrations (MICs). The oils' anticancer potential against several cancer types was also studied using the MTT assay and reported as the toxic doses that resulted in a 50% reduction in cancer cell growth (LD50). RESULTS: Phenolic compounds in the EEs from both plants were analysed by HPLC and demonstrated a rich flavonoid content. Chemical analysis of the essential oil from Ocimum basilicum revealed 26 unique compounds, with linalool (52.1%) and linalyl acetate (19.1%) as the major compounds. A total of 29 compounds were identified in the essential oil from Thymus algeriensis, with α-terpinyl acetate (47.4%), neryl acetate (9.6%), and α-pinene (6.8%) as the major compounds. The ethanolic extracts and essential oils from both plants exhibited moderate antioxidant activities and moderate to weak antimicrobial activities. Furthermore, anticancer activities against the examined human cancer cell lines were associated with only the EOs from both plants, with LD50 values ranging between 300 and 1000 µg/mL. CONCLUSION: The results suggest that the bioactive compounds found in the ethanolic extracts and essential oils from Ocimum basilicum and Thymus algeriensis, with diverse antioxidant, antimicrobial and anticancer activities, may have beneficial applications in nutraceutical and pharmaceutical technologies.


Assuntos
Ocimum basilicum/química , Óleos Voláteis/química , Óleos Vegetais/química , Thymus (Planta)/química , Argélia , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Linhagem Celular Tumoral , Sobrevivência Celular , Cromatografia Líquida de Alta Pressão , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Humanos , Fenol/química , Fenol/farmacologia , Óleos Vegetais/farmacologia
9.
Food Chem ; 297: 124900, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253312

RESUMO

Nonthermal plasma treatment has been a widely acknowledged effective method for food sterilization. This study presents the potential of nonthermal dielectric barrier discharge (DBD) plasma treatment for sterilization of the surface of the fresh wet noodles (FWNs). The plasma treatment achieved a more than one logarithmic reduction of the total bacterial count and total mold count as measured by counting the total microorganisms and filamentous fungi, respectively. In addition, the qualities of FWNs exposed to nonthermal DBD plasma treatment had no undesirable changes to color, texture, acidity and water distribution as measured by a texture analyzer, color meter and low-field nuclear magnetic resonance (LF-NMR), respectively. Thus, nonthermal DBD plasma treatment is a promising alternative to the traditional sterilization method applied in FWN industry and provides a new idea for the preservation and processing of fresh food.


Assuntos
Análise de Alimentos/métodos , Gases em Plasma/química , Bactérias/efeitos dos fármacos , Cor , Fungos/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Esterilização/métodos , Paladar/fisiologia , Água/química
10.
Sci Total Environ ; 684: 314-325, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31153078

RESUMO

Conventional agriculture still relies on the general use of agrochemicals (herbicides, fungicides and insecticides) to control various pests (weeds, fungal pathogens and insects), to ensure the yield of crop and to feed a constantly growing population. The generalized use of pesticides in agriculture leads to the contamination of soil and other connected environmental resources. The persistence of pesticide residues in soil is identified as a major threat for in-soil living organisms that are supporting an important number of ecosystem services. Although authorities released pesticides on the market only after their careful and thorough evaluation, the risk assessment for in-soil living organisms is unsatisfactory, particularly for microorganisms for which pesticide toxicity is solely considered by one global test measuring N mineralization. Recently, European Food Safety Authority (EFSA) underlined the lack of standardized methods to assess pesticide ecotoxicological effects on soil microorganisms. Within this context, there is an obvious need to develop innovative microbial markers sensitive to pesticide exposure. Biomarkers that reveal direct effects of pesticides on microorganisms are often viewed as the panacea. Such biomarkers can only be developed for pesticides having a mode of action inhibiting a specific enzyme not only found in the targeted organisms but also in microorganisms which are considered as "non-target organisms" by current regulations. This review explores possible ways of innovation to develop such biomarkers for herbicides. We scanned the herbicide classification by considering the mode of action, the targeted enzyme and the ecotoxicological effects of each class of active substance in order to identify those that can be tracked using sensitive microbial markers.


Assuntos
Bactérias/efeitos dos fármacos , Biomarcadores/análise , Ecotoxicologia/métodos , Fungos/efeitos dos fármacos , Herbicidas/toxicidade , Medição de Risco/métodos , Microbiologia do Solo , Testes de Toxicidade
11.
Int J Nanomedicine ; 14: 3955-3966, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31239665

RESUMO

Background: Sulconazole (SCZ) is a broad-spectrum transdermally administered anti-fungicidal agent. However, the therapeutic effect of SCZ is generally limited by its poor water solubility. This present study aimed to develop and evaluate sulconazole-loaded nanoemulsions (SCZ-NEs) for enhancement of the transdermal permeation and antifungal activity. Methods: A spontaneous titration method was applied to prepare the SCZ-NEs. And the optimized formulation of SCZ-NEs was screened by central composite design (CCD). In addition, the characteristics of the SCZ-NEs were evaluated, including particle size, zeta potential, drug loading (DL%) and encapsulation efficiency (EE%). The morphology of SCZ-NEs was observed by transmission electron microscopy (TEM). Franz diffusion cells were used to evaluate the transdermal permeability of the SCZ-NEs. The antifungal activity of the SCZ-NEs was measured by a zone of inhibition (ZOI) test. Results: The optimized SCZ-NEs possessed a moderate particle size of 52.3±3.8 nm, zeta potential of 23.3±1.2 mV, DL% of 0.47±0.05% and EE% of 87.1±3.2%. The ex vivo skin permeation study verified that the cumulative permeability (Qn) and penetration rate (Js) of the optimized SCZ-NEs were about 1.7-fold higher than that of a commercial reference, miconazole (MCZ) cream and 3-fold higher than that of SCZ-DMSO solution. The optimized SCZ-NEs exhibited zone of inhibition (ZOI) values of 23.5±2.4 and 20.4±2.5 mm against C. albicans and T. rubrum, which were larger compared with these of the MCZ cream and SCZ-DMSO solution. Conclusion: SCZ-NEs were effectively developed to overcome the poor solubility of SCZ, promote SCZ permeation through the skin and improve its antifungal activity. Thus, the SCZ-NEs are a promising percutaneous administration for skin fungal infections induced by C. albicans and T. rubrum.


Assuntos
Antifúngicos/farmacologia , Emulsões/química , Imidazóis/farmacologia , Nanopartículas/química , Absorção Cutânea/efeitos dos fármacos , Administração Cutânea , Análise de Variância , Animais , Candida albicans/efeitos dos fármacos , Fungos/efeitos dos fármacos , Masculino , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Óleos/química , Tamanho da Partícula , Permeabilidade/efeitos dos fármacos , Transição de Fase , Ratos Sprague-Dawley , Solubilidade , Tensoativos/química
12.
Chem Biol Interact ; 308: 294-303, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31158333

RESUMO

The emergence of multidrug resistant (MDR) pathogens is a global threat and has created problems in providing adequate treatment of many infectious diseases. Although the conventional antimicrobial agents are quite effective against several pathogens, yet there is a need for more effective antimicrobial agents against MDR pathogens. Herbal drugs and phytochemicals have been used for their effective antimicrobial activity from ancient times and there is an increasing trend for development of plant based natural products for the prevention and treatment of pathogenic diseases. One of the strategies for effective resistance modification is the use of antimicrobial agent-phytochemical combinations that will neutralize the resistance mechanism, enabling the drug to still be effective against resistant microbes. These phytochemicals can work by several strategies, such as inhibition of target modifying and drug degrading enzymes or as efflux pumps inhibitors. A plethora of herbal extracts, essential oils and isolated pure compounds have been reported to act synergistically with existing antibiotics, antifungals and chemotherapeutics and augment the activity of these drugs. Considerable increases in the susceptibility pattern of several microbes towards the natural antimicrobials and their combinations were observed as indicated by significant decline in minimum inhibitory concentrations. This review paper summarizes the current developments regarding synergistic interactions of plant extracts and isolated pure compounds in combination with existing antibacterial, antifungal agents and chemotherapeutics. The effect of these agents on the susceptibility patterns of these pathogens and possible mechanisms of action are described in detail. In conclusion, many phytochemicals in combination with existing drugs were found to act as resistance modifying agents and proper combinations may rescue the efficacy of important lifesaving antimicrobial agents.


Assuntos
Anti-Infecciosos/farmacologia , Resistência a Medicamentos/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/metabolismo , Antifúngicos/química , Antifúngicos/farmacologia , Antivirais/química , Antivirais/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Vírus de DNA/efeitos dos fármacos , Sinergismo Farmacológico , Fungos/efeitos dos fármacos , Compostos Fitoquímicos/química , Compostos Fitoquímicos/metabolismo , beta-Lactamases/química , beta-Lactamases/metabolismo
13.
Phytochemistry ; 164: 192-205, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31174083

RESUMO

The chemical composition of five marine microalgae (Dunaliella sp., Dunaliella salina, Chaetoceros calcitrans, Chaetoceros gracilis and Tisochrysis lutea) was investigated through nuclear magnetic resonance (NMR) spectroscopic study of the soluble material obtained by sequential extraction with hexane, ethyl acetate (AcOEt) and methanol of biomass from stationary phase cultures. Hexane extracted the major lipids present in the microalgae during the stationary phase of growth, which correspond to storage lipids. Triacylglycerols (TGs) were the only storage lipids produced by Dunaliella and Chaetoceros. In contrast, T. lutea predominantly stored polyunsaturated long-chain alkenones, with sterols also detected as minor components of the hexane extract. The molecular structure of brassicasterol was determined in T. lutea and the presence of squalene in this sample was also unequivocally detected. Monogalactosyldiacylglycerols (MGDGs) and pigments were concentrated in the AcOEt extracts. C. calcitrans and D. salina constituted an exception due to the high amount of TGs and glycerol produced, respectively, by these two strains. Chlorophylls a and b and ß-carotene were the major pigments synthesized by Dunaliella and chlorophyll a and fucoxanthin were the only pigments detected in Chaetoceros and T. lutea. Information concerning the acyl chains present in TGs and MGDGs as well as the positional distribution of acyl chains on the glycerol moiety was obtained by NMR analysis of hexane and AcOEt extracts, with results consistent with those expected for the genera studied. Fatty acid composition of TGs in the two Dunaliella strains was different, with polyunsaturated acyl chains almost absent in the storage lipids produced by D. salina. Except in C. calcitrans, the polar nature of soluble compounds was inferred through the relative extraction yield using methanol as the extraction solvent. Glycerol was the major component of this fraction for the Dunaliella strains. In T. lutea 1,4/2,5-cyclohexanetetrol (CHT) and dimethylsulfoniopropionate (DMSP) preponderated. CHT was also the major polyol present in the Chaetoceros strains in which DMSP was not detected, but prominent signals of 2,3-dihydroxypropane-1-sulfonate (DHSP) were observed in the 1H NMR spectra of methanolic extracts. The presence of DHSP confirms the production of this metabolite by diatoms. In addition, several other minor compounds (digalactosyldiacyglycerols (DGDGs), sulphoquinovosyldiacylglycerols (SQDGs), amino acids, carbohydrates, scyllo-inositol, mannitol, lactic acid and homarine) were also identified in the methanolic extracts. The antibacterial and antibiofilm activities of the extracts were tested. The AcOEt extract from C. gracilis showed a moderate antibiofilm activity.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Microalgas/química , Ressonância Magnética Nuclear Biomolecular , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antifúngicos/química , Antifúngicos/isolamento & purificação , Fungos/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Microalgas/metabolismo , Testes de Sensibilidade Microbiana , Conformação Molecular
14.
J Med Microbiol ; 68(7): 1047-1052, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31169488

RESUMO

INTRODUCTION: Miramistin is a topical antiseptic with broad antimicrobial activity that was developed in the Soviet Union during the Cold War. AIM: To investigate the antifungal activity of miramistin against clinically relevant drug-resistant fungi. METHODOLOGY: The in vitro activity of miramistin was determined following Clinical and Laboratory Standards Institute (CLSI) guidelines. Mammalian cell toxicity was tested using a McCoy cell line and topical and systemic tolerability, and in vivo efficacy was tested using Galleria mellonella models. RESULTS: The minimal inhibitory concentration (MIC) range against fungi was 1.56-25 mg l-1 (GM 3.13 mg l-1 ). In the G. mellonella model, miramistin provided potent survival benefits for Candida albicans and Aspergillus fumigatus infection. Miramistin was tolerated by McCoy cell lines at concentrations up to 1000 mg l-1 and was systemically safe in G. mellonella at 2000 mg kg-1. Topical administration at 32 000 mg l-1 was well tolerated with no adverse effects. CONCLUSION: These findings support further investigation of miramistin and suggest its possible use for treatment of superficial fungal infections.


Assuntos
Antifúngicos/farmacologia , Compostos de Benzalcônio/farmacologia , Fungos/efeitos dos fármacos , Animais , Antifúngicos/administração & dosagem , Antifúngicos/toxicidade , Compostos de Benzalcônio/administração & dosagem , Compostos de Benzalcônio/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Farmacorresistência Fúngica , Camundongos , Testes de Sensibilidade Microbiana , Nucleopolyhedrovirus/efeitos dos fármacos
16.
Mar Drugs ; 17(5)2019 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-31035506

RESUMO

Three new diketopiperazine alkaloids, including two oxepine-containing diketopiperazines, chrysopiperazines A and B (1 and 2), and one quinazoline-containing diketopiperazine, chrysopiperazine C (5), together with three known analogues (3, 4, and 6), were isolated from the gorgonian-derived Penicillium chrysogenum fungus. The relative and absolute configurations of C-3 and C-15 in 1 and 2, C-3 and C-14 in 5 were established by NOE modified Marfey's analysis and electronic circular dichroism (ECD) calculations. Particularly, the absolute configurations of C-19 in 1 and 3, which was very challenging to be identified due to the flexible conformation in a short aliphatic chain, were successfully determined by the vibrational circular dichroism (VCD) method, supplying with a reliable and optional method to define the absolute configurations. Additionally, this is the first report on oxepine-containing diketopiperazines from the genus Penicillium.


Assuntos
Alcaloides/química , Antozoários/microbiologia , Dicetopiperazinas/química , Penicillium chrysogenum/química , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Dicroísmo Circular , Dicetopiperazinas/isolamento & purificação , Dicetopiperazinas/farmacologia , Fungos/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Conformação Molecular , Estrutura Molecular , Espectroscopia de Prótons por Ressonância Magnética
17.
Sci Total Environ ; 677: 272-280, 2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-31059871

RESUMO

Although many studies have reported the negative effects of elevated O3 on plant physiological characteristics, the influence of elevated O3 on below-ground processes and soil microbial functioning is less studied. In this study, we examined the effects of elevated O3 on soil properties, soil microbial biomass, as well as microbial community composition using high-throughput sequencing. Throughout one growing season, one-year old seedlings of two important endemic trees in subtropical China: Taxus chinensis (Pilger) Rehd. var. chinensis, and Machilus ichangensis Rehd. Et Wils, were exposed to charcoal-filtered air (CF as control), 100 nl l-1 (E100) or 150 nl l-1 (E150) O3-enriched air, in open top chambers (OTCs). We found that only higher O3 exposure (E150) significantly decreased soil microbial biomass carbon and nitrogen in M. ichangensis, and the contents of organic matter were significantly decreased by E150 in both tree species. Although both levels of O3 exposure decreased NO3-N in T. chinensis, only E150 increased NO3-N in M. ichangensis, and there were no effects of O3 on NH4-N. Moreover, elevated O3 elicited changes in soil microbial community structure and decreased fungal diversity in both M. ichangensis and T. chinensis. However, even though O3 exposure reduced bacterial diversity in M. ichangensis, no effect of O3 exposure on bacterial diversity was detected in soil grown with T. chinensis. Our results showed that elevated O3 altered the abundance of bacteria and fungi in general, and in particular reduced nitrifiers and increased the relative abundance of some fungal taxa capable of denitrification, which may stimulate N2O emissions. Overall, our findings indicate that elevated O3 not only impacts the soil microbial community structure, but may also exert an influence on the functioning of microbial communities.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Carbono/metabolismo , Microbiota/efeitos dos fármacos , Nitrogênio/metabolismo , Ozônio/efeitos adversos , Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Fungos/efeitos dos fármacos , Fungos/fisiologia , Sequenciamento de Nucleotídeos em Larga Escala , Lauraceae/efeitos dos fármacos , Lauraceae/crescimento & desenvolvimento , Microbiologia do Solo , Taxus/efeitos dos fármacos , Taxus/crescimento & desenvolvimento
18.
Environ Pollut ; 251: 668-680, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31108300

RESUMO

Based on long-term systematic sampling, information is currently limited regarding the impacts of different air pollution levels on variations of bacteria, fungi and ammonia-oxidizing microorganisms (AOMs) in fine particulate matter (PM2.5), especially their interactions. Here, PM2.5 samples were weekly collected at different air pollution levels in Beijing, China during one-year period. Microbial composition was profiled using Illumina sequencing, and their interactions were further investigated to reveal the hub genera with network analysis. Diversity of bacteria and fungi showed obvious seasonal variations, and the heavy- or severe-pollution levels mainly affected the diversity and composition of bacteria, but not fungi. While, the community structure of both bacteria and fungi was influenced by the combination of air pollution levels and seasons. The most abundant bacterial genera and some genera with highest abundance in heavy- or severe-pollution days were the hub bacteria in PM2.5. Whereas, only the dominant fungi in light-pollution days in winter were the hub fungi in PM2.5. The complex positive correlations of bacterial or fungal pathogens would aggravate the air pollution effects on human health, despite of their low relative abundances. Moreover, the strong co-occurrence and co-exclusion patterns of bacteria and fungi in PM2.5 were identified. Furthermore, the hub environmental factors (e.g., relative humidity and atmospheric pressure) may play central roles in the distributions of bacteria and fungi, including pathogens. Importantly, AOMs showed significant co-occurrence patterns with the main bacterial and fungal genera and potential pathogens, providing possible microbiological evidences for controlling ammonia emissions to effectively reduce PM2.5 pollution. These results highlighted the more obvious air pollution impacts on bacteria than fungi, and the complex bacterial-fungal interactions, as well as the important roles of AOMs in airborne microbial interactions webs, improving our understanding of bioaerosols in PM2.5.


Assuntos
Microbiologia do Ar , Poluentes Atmosféricos/efeitos adversos , Amônia/metabolismo , Bactérias/efeitos dos fármacos , Fungos/efeitos dos fármacos , Material Particulado/toxicidade , Poluentes Atmosféricos/análise , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Pequim , Monitoramento Ambiental , Fungos/classificação , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Humanos , Interações Microbianas , Tamanho da Partícula , Material Particulado/análise , Estações do Ano
19.
J Sci Food Agric ; 99(12): 5432-5443, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31099414

RESUMO

BACKGROUND: The aim of this experiment was to determine the essential oil, flavonoid and phenolic acid contents as well as yields of raw material collected from different morphological parts of Greek oregano in five consecutive developmental stages. Antibacterial and antifungal properties of methanol and hexane extracts from the aerial parts of Greek oregano were assessed as well. RESULTS: The findings showed that Greek oregano grown in the cool climate of central Europe had a considerable variation in the essential oil yield and chemical composition related to the harvesting stage. Forty volatile compounds were detected in essential oils, with the highest amount of carvacrol, thymol, p-cymene and γ-terpinene, constituting in total from 90.72 to 92.9%. CONCLUSION: Different morphological parts of the plants contained different amounts of essential oils, with dominant amounts in the flowers. The essential oil content systematically increased, reaching its maximum in the full blooming period. In that phase, the plants produced the highest yields of aboveground parts and provided approximately 190 L ha-1 of essential oils. Mainly owing to its content of phenolic compounds, the Greek oregano raw material exhibited relatively high antioxidant activity. The data obtained clearly showed the inhibitory activity of methanol and hexane extracts against pathogenic bacteria and fungi. © 2019 Society of Chemical Industry.


Assuntos
Origanum/química , Extratos Vegetais/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Flavonoides/química , Flavonoides/farmacologia , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Origanum/crescimento & desenvolvimento , Fenóis/química , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Controle de Qualidade , Fatores de Tempo
20.
IET Nanobiotechnol ; 13(2): 134-143, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31051443

RESUMO

This work explores the rapid synthesis of silver nanoparticles (AgNPs) from Musa paradisiaca (M. paradisiaca) bract extract. The bio-reduction of Ag+ ion was recorded using ultraviolet-visible spectroscopy by a surface plasmon resonance extinction peak with an absorbance at 420 nm. The phytoconstituents responsible for the reduction of AgNPs was probed using Fourier transform infrared spectroscopy. The X-ray diffraction pattern confirmed the formation of crystalline AgNPs that were analogous to selected area electron diffraction patterns. Morphological studies showed that the obtained AgNPs were monodispersed with an average size of 15 nm. The biologically synthesised AgNPs showed higher obstruction against tested phytopathogens. The synthesised AgNPs exhibited higher inhibitory zone against fungal pathogen Alternaria alternata and bacterial pathogen Pseudomonas syringae. Free radical scavenging potential of AgNPs was investigated using 1,1-diphenyl-2-picryl hydroxyl and 2,2-azinobis (3-ethylbenzothiazoline)-6-sulphonic acid assays which revealed that the synthesised AgNPs act as a potent radical scavenger. The catalytic efficiency of the synthesised AgNPs was investigated for azo dyes, methyl orange (MO), methylene blue (MB) and reduction of o-nitrophenol to o-aminophenol. The results portrayed that AgNPs act as an effective nanocatalyst to degrade MO to hydrazine derivatives, MB to leucomethylene blue, and o-nitro phenol to o-amino phenol.


Assuntos
Anti-Infecciosos/química , Depuradores de Radicais Livres/química , Nanopartículas Metálicas/química , Musa/química , Extratos Vegetais/metabolismo , Prata/química , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Compostos Azo/análise , Compostos Azo/metabolismo , Bactérias/efeitos dos fármacos , Compostos de Bifenilo/análise , Compostos de Bifenilo/metabolismo , Depuradores de Radicais Livres/metabolismo , Depuradores de Radicais Livres/farmacologia , Fungos/efeitos dos fármacos , Química Verde , Picratos/análise , Picratos/metabolismo , Extratos Vegetais/química , Prata/metabolismo
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