Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 395
Filtrar
1.
J Med Microbiol ; 70(4)2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33909551

RESUMO

Candida albicans is an opportunistic pathogen accounting for the majority of cases of Candida infections. Currently, C. albicans are developing resistance towards different classes of antifungal drugs and this has become a global health burden that does not spare Lebanon. This study aims at determining point mutations in genes known to be involved in resistance acquisition and correlating resistance to virulence and ergosterol content in the azole resistant C. albicans isolate CA77 from Lebanon. This pilot study is the first of its kind to be implemented in Lebanon. We carried out whole genome sequencing of the azole resistant C. albicans isolate CA77 and examined 18 genes involved in antifungal resistance. To correlate genotype to phenotype, we evaluated the virulence potential of this isolate by injecting it into BALB/c mice and we quantified membrane ergosterol. Whole genome sequencing revealed that eight out of 18 genes involved in antifungal resistance were mutated in previously reported and novel residues. These genotypic changes were associated with an increase in ergosterol content but no discrepancy in virulence potential was observed between our isolate and the susceptible C. albicans control strain SC5314. This suggests that antifungal resistance and virulence potential in this antifungal resistant isolate are not correlated and that resistance is a result of an increase in membrane ergosterol content and the occurrence of point mutations in genes involved in the ergosterol biosynthesis pathway.


Assuntos
Candida albicans/efeitos dos fármacos , Candida albicans/genética , Farmacorresistência Fúngica/genética , Sequenciamento Completo do Genoma , Animais , Azóis/farmacologia , Candida albicans/química , Candida albicans/patogenicidade , Ergosterol/análise , Genótipo , Humanos , Líbano , Camundongos , Camundongos Endogâmicos BALB C , Fenótipo , Projetos Piloto , Mutação Puntual , Virulência
2.
Food Chem ; 340: 127926, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32919357

RESUMO

This paper provides a method for the quantification of sterols in different types of calf feedstuffs based on soy, sunflower, hay, calf feed and a mixture of all of them. The free fraction and the total sterolic fraction, after saponification and acidic hydrolysis of the samples, are extracted by solvent and the sterols are identified/quantified by reversed phase HPLC coupled to tandem mass spectrometry by atmospheric pressure chemical ionization. After the recovery evaluation, the method is validated in terms of linearity (coefficient of determination R2), repeatability (coefficient of variation RSD), limit of detection and quantification. In most of the cases, the most representative phytosterol is ß-sitosterol, followed by campesterol or stigmasterol and by other minor sterols such as fucosterol, and Δ-5-avenasterol. In addition, also cholesterol and ergosterol, if present, are evaluated in all the samples. As far as we know, very little information is available on the investigated feeds, which are commonly used on farms. The results of this survey were compared to other studies, if present in literature, showing good agreement. The proposed method resulted to be simple, fast and suitable for application to other sterols, feedstuffs and derived foods. The knowledge of the sterolic content and composition is getting more and more important, both in terms of comprehension of the vegetal biochemistry and as basis for sterolomic studies.


Assuntos
Ração Animal/análise , Fitosteróis/análise , Animais , Pressão Atmosférica , Bovinos , Colesterol/análogos & derivados , Cromatografia Líquida de Alta Pressão/métodos , Ergosterol/análise , Helianthus , Sitosteroides/análise , Soja/química , Estigmasterol/análogos & derivados , Estigmasterol/análise , Espectrometria de Massas em Tandem
3.
Sci Rep ; 10(1): 6547, 2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32300135

RESUMO

Microbial volatile compounds (MVCs) significantly influence the growth of plants and phytopathogens. However, the practical application of MVCs at the field level is limited by the fact that the concentrations at which these compounds antagonize the pathogens are often toxic for the plants. In this study, we investigated the effect of dimethyl disulfide (DMDS), one of the MVCs produced by microorganisms, on the fitness of tomato plants and its fungicidal potential against a fungal phytopathogen, Sclerotinia minor. DMDS showed strong fungicidal and plant growth promoting activities with regard to the inhibition of mycelial growth, sclerotia formation, and germination, and reduction of disease symptoms in tomato plants infected with S. minor. DMDS exposure significantly upregulated the expression of genes related to growth and defense against the pathogen in tomato. Especially, the overexpression of PR1 and PR5 suggested the involvement of the salicylic acid pathway in the induction of systemic resistance. Several morphological and ultrastructural changes were observed in the cell membrane of S. minor and the expression of ergosterol biosynthesis gene was significantly downregulated, suggesting that DMDS damaged the membrane, thereby affecting the growth and pathogenicity of the fungus. In conclusion, the tripartite interaction studies among pathogenic fungus, DMDS, and tomato revealed that DMDS played roles in antagonizing pathogen as well as improving the growth and disease resistance of tomato. Our findings provide new insights into the potential of volatile DMDS as an effective tool against sclerotial rot disease.


Assuntos
Antifúngicos/farmacologia , Ascomicetos/fisiologia , Membrana Celular/patologia , Resistência à Doença , Dissulfetos/farmacologia , Interações Hospedeiro-Patógeno , Doenças das Plantas/microbiologia , Ascomicetos/efeitos dos fármacos , Ascomicetos/ultraestrutura , Membrana Celular/efeitos dos fármacos , Família 51 do Citocromo P450/metabolismo , Ergosterol/análise , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glucanos/metabolismo , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/genética , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/microbiologia , Testes de Sensibilidade Microbiana , Controle Biológico de Vetores , Transcrição Genética/efeitos dos fármacos , Compostos Orgânicos Voláteis/farmacologia
4.
Mycotoxin Res ; 36(1): 103-114, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31512221

RESUMO

Canadian oat harvest samples, deliveries to processors, and train shipments from primary elevators were collected from mid-2014 through mid-2017 and analyzed for 26 mycotoxins and the fungal biomarker ergosterol. Of the 26 mycotoxins, 7 were not detected in any sample. The most frequently measured mycotoxins were beauvericin (in over 95% of samples analyzed), followed by tentoxin, culmorin, alternariol, alternariol methyl ether, and deoxynivalenol. Median concentrations of the Fusarium-produced mycotoxins ranged from 68 to 1142 µg/kg for deoxynivalenol, 39 to 188 µg/kg for HT-2 and T-2 toxins, 66 to 232 µg/kg for nivalenol, and less than 35 µg/kg for beauvericin. Median concentrations of the sum of Alternaria-produced mycotoxins were all less than 250 µg/kg. Concentrations of analytes varied among years, as well as among growing areas, for the harvest samples. Ergosterol, Fusarium, and Alternaria mycotoxin concentrations appeared to increase from the west toward the eastern Prairies and the province of Quebec; the differences were not statistically significant though. Ochratoxin A in deliveries and train shipments showed annual cyclic increases in the late summer. The results of the survey demonstrate the general compliance of Canadian oats with existing maximum levels for mycotoxins and indicate that in late summer and in years with increased Fusarium infection, there can be a need for monitoring of ochratoxin A and deoxynivalenol, respectively, to mitigate risks of noncompliant grain.


Assuntos
Avena/química , Grão Comestível/química , Ergosterol/análise , Micotoxinas/análise , Alternaria/metabolismo , Aspergillus/metabolismo , Avena/microbiologia , Canadá , Depsipeptídeos/análise , Contaminação de Alimentos/análise , Fusarium/metabolismo , Penicillium/metabolismo , Peptídeos Cíclicos/análise , Medição de Risco , Estações do Ano , Sesquiterpenos/análise
5.
Future Microbiol ; 14: 1221-1233, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31625442

RESUMO

Aim: This study investigated the effect of terpinen-4-ol against Sporothrix schenckii complex and its interactions with antifungals. Materials & methods: The antifungal activity of terpinen-4-ol was evaluated by broth microdilution. The potential effect on cellular ergosterol concentration was evaluated by spectrophotometry. The antibiofilm activity was evaluated by violet crystal staining and XTT reduction assay. The potential pharmacological interactions with antifungals were evaluated by the checkerboard assay. Results: terpinen-4-ol (T-OH) showed minimal inhibitory concentrations ranging from 4 to 32 mg/l decreasing cellular ergosterol content and presented a SMIC ranging from 64 to 1024 mg/l for Sporothrix spp. The combinations of T-OH with itraconazole or terbinafine were synergistic. Conclusion: T-OH has antifungal activity against Sporothrix spp. and acts synergistically with standard antifungals.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Sporothrix/efeitos dos fármacos , Sporothrix/crescimento & desenvolvimento , Terpenos/farmacologia , Sinergismo Farmacológico , Ergosterol/análise , Testes de Sensibilidade Microbiana
6.
Food Res Int ; 125: 108541, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31554101

RESUMO

Response surface methodology was applied to optimize the recovery of ergosterol from an agroindustrial residue of Agaricus blazei Murrill, by comparing conventional (heat-assisted extraction, HAE) and more sustainable non-conventional approaches (ultrasound and microwave-assisted extractions, UAE and MAE, respectively). A circumscribed central composite design was employed to optimize and describe the interactive effects among variables of the HAE, MAE (time and temperature) and UAE systems (time and ultrasound power), and their performances compared with the standard soxhlet extraction system. The optimum conditions were predicted as 150 min, 81.6 °C for HAE, 30 min, 400 W for UAE, and 25 min, 134.6 °C, for the MAE system. The UAE system was identified as the most appropriate technique to obtain extracts with the highest amount of ergosterol, followed by MAE and HAE. Overall, these results demonstrate the potential of using the fruiting bodies of A. blazei as a suitable source to obtain ergosterol-rich extracts, which can be used as an ingredient for various bio-based industrial applications.


Assuntos
Agaricus/química , Fracionamento Químico/métodos , Ergosterol/isolamento & purificação , Ergosterol/análise , Ergosterol/química , Micro-Ondas , Modelos Estatísticos , Sonicação
7.
Food Funct ; 10(10): 6633-6643, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31555775

RESUMO

In this study, we investigated the potential bioactivities of an ethanol extract of Hericium novae-zealandiae and four of its constituents, namely hericenone C, hericene B, ergosterol and ergosterol peroxide. The proliferation of three prostate cancer cell lines, namely DU145, LNCaP and PC3, was evaluated after treatment with the extract and constituents. It was found that both the ethanol extract and ergosterol peroxide possess anti-proliferative activities to the three prostate cancer cell lines. Ergosterol peroxide was considered likely to be one of the major compounds responsible for the anti-proliferative effect of the ethanol extract. Subsequently, the results of RT-qPCR assay showed two possible mechanisms for these anti-proliferative activities. One is apoptosis, supported by the up-regulation of CASP3, CASP8, CASP9, and an increase in the ratio of Bax/Bcl2. The other is anti-inflammation, indicated by the down-regulation of IL6 and up-regulation of IL24. The ethanol extract also exhibited antioxidant and AChE inhibitory (though weak) activities. However, none of the four compounds were found to account for these latter two activities. This is the first report of the bioactivities, and the corresponding active ingredients of lipophilic constituents from H. novae-zealandiae.


Assuntos
Agaricales/química , Extratos Vegetais/análise , Extratos Vegetais/farmacologia , Apoptose/efeitos dos fármacos , Caspases/genética , Caspases/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ergosterol/análise , Ergosterol/isolamento & purificação , Ergosterol/farmacologia , Humanos , Interleucina-6/genética , Interleucina-6/metabolismo , Interleucinas/genética , Interleucinas/metabolismo , Nova Zelândia , Fenóis/análise , Fenóis/isolamento & purificação , Fenóis/farmacologia , Extratos Vegetais/isolamento & purificação
8.
J Mycol Med ; 29(3): 210-218, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400863

RESUMO

OBJECTIVE: The rise in fungal infections is alarming due to emergence of multidrug drug resistance (MDR). Hence elucidating novel drug targets to circumvent the problem of MDR warrants immediate attention. This study analyzes the effect of retrograde (RTG) signaling disruption on major MDR mechanisms and virulence of the human pathogenic fungal species Candida albicans. MATERIAL AND METHODS: Drug transporter activity was measured by rhodamine 6G (R6G) efflux. Membrane damage was studied by propidium iodide intake and ergosterol level determination. Cell wall effect was estimated by quantifying chitin levels and cell sedimentation rate. Biofilm formation was visualized by calcoflour white and crystal violet staining and measured by dry mass and MTT assay. Cell adherence to buccal epithelial cell was determined by trypan blue staining and MTT assay. Virulence was studied using nematode model Caenorhabditis elegans. RESULT: We demonstrated that mutant of transcription factor CaRTG3 leads to impaired efflux activity of ATP Binding Cassette (ABC) superfamily multidrug transporters. We further uncover that rtg3 mutant exhibited a disrupted membrane, decreased ergosterol levels and increased chitin content. Furthermore, RTG signaling disruption leads to inhibited biofilm formation and cell adherence to buccal epithelial cells. Lastly, rtg3 mutant displayed a reduced infectivity in C. elegans illustrating its vulnerability as antifungal target. Interestingly, all the abrogated phenotypes could be rescued in the revertant strain of rtg3 mutant. CONCLUSION: Present study establishes a link between RTG signaling, drug efflux and biofilm formation and validates CaRTG3 as antifungal target. Intricate studies are needed to further understand and exploit this therapeutic opportunity.


Assuntos
Biofilmes/crescimento & desenvolvimento , Candida albicans/metabolismo , Quitina/análise , Ergosterol/análise , Proteínas de Membrana Transportadoras/genética , Transdução de Sinais , Animais , Transporte Biológico , Caenorhabditis elegans/microbiologia , Candida albicans/genética , Candida albicans/patogenicidade , Candidíase/microbiologia , Modelos Animais de Doenças , Proteínas de Membrana Transportadoras/metabolismo , Virulência
9.
FEMS Yeast Res ; 19(6)2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31425603

RESUMO

In Saccharomyces cerevisiae, acyl-coenzyme A desaturation by Ole1 requires molecular oxygen. Tween 80, a poly-ethoxylated sorbitan-oleate ester, is therefore routinely included in anaerobic growth media as a source of unsaturated fatty acids (UFAs). During optimization of protocols for anaerobic bioreactor cultivation of this yeast, we consistently observed growth of the laboratory strain S. cerevisiae CEN.PK113-7D in media that contained the anaerobic growth factor ergosterol, but lacked UFAs. To minimize oxygen contamination, additional experiments were performed in an anaerobic chamber. After anaerobic precultivation without ergosterol and Tween 80, strain CEN.PK113-7D and a congenic ole1Δ strain both grew during three consecutive batch-cultivation cycles on medium that contained ergosterol, but not Tween 80. During these three cycles, no UFAs were detected in biomass of cultures grown without Tween 80, while contents of C10 to C14 saturated fatty acids were higher than in biomass from Tween 80-supplemented cultures. In contrast to its UFA-independent anaerobic growth, aerobic growth of the ole1Δ strain strictly depended on Tween 80 supplementation. This study shows that the requirement of anaerobic cultures of S. cerevisiae for UFA supplementation is not absolute and provides a basis for further research on the effects of lipid composition on yeast viability and robustness.


Assuntos
Anaerobiose , Suplementos Nutricionais/análise , Ácidos Graxos Insaturados/análise , Oxigênio/metabolismo , Saccharomyces cerevisiae/metabolismo , Estearoil-CoA Dessaturase/metabolismo , Biomassa , Reatores Biológicos , Meios de Cultura , Ergosterol/análise , Ácidos Graxos/metabolismo , Ácidos Graxos Insaturados/biossíntese , Lipídeos/análise , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Estearoil-CoA Dessaturase/genética
10.
J Food Biochem ; 43(8): e12960, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31368560

RESUMO

Ergosterol, an important constituent of fungal cell wall, was started to be used as a quality parameter for the tomatoes and derivatives instead of Howard mold count (HMC). In addition, patulin is another important microbiological quality indicator of molds such as Penicillium, Aspergillus, and Byssochlamys. In this study, it is aimed to identify the relationship between HMC, patulin, and ergosterol in juices produced from the tomatoes which has the surface rotten of 0% (sound), 25%, 50%, 75%, and 100%. As the rotten proportion increased, HMC, ergosterol, and patulin values increased. Linear correlations (r) between HMC, ergosterol, patulin, and rotten proportion were calculated as 0.99, 0.99, and 0.98, respectively. In addition, linear correlations between HMC and ergosterol (r = 0.95), HMC and patulin (r = 0.95) and ergosterol and patulin (r = 0.98) were found. In contrast, non-linear correlation between pH, brix and titratable acidity, and the rotten proportion was determined. PRACTICAL APPLICATIONS: The manuscript has provided the relationship between HMC, patulin, and ergosterol in juices produced from the tomatoes which have the surface rotten of 0% (sound), 25%, 50%, 75%, and 100%. Linear correlations between rotten proportions of tomatoes and HMC, ergosterol, patulin and between HMC and ergosterol, HMC and patulin, and ergosterol and patulin were determined in juices produced from rotten tomatoes. Patulin indicated correlation with HMC and ergosterol in juices produced from rotten tomatoes. In addition to HMC and ergosterol, patulin has great potential for the assessment of tomato products as associated with the rotten proportion.


Assuntos
Ergosterol/análise , Frutas/química , Fungos/crescimento & desenvolvimento , Lycopersicon esculentum/microbiologia , Patulina/análise , Contaminação de Alimentos/análise , Frutas/microbiologia , Fungos/metabolismo , Lycopersicon esculentum/química , Patulina/metabolismo , Controle de Qualidade
11.
Zhongguo Zhong Yao Za Zhi ; 44(10): 1978-1982, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31355550

RESUMO

Online gradient extraction-high performance liquid chromatography( HPLC) method was developed for simultaneous determination of high and low polar components in Cordyceps. The sample powder of Cordyceps was uniformly mixed with diatomaceous earth,packed into extraction tank,and installed into the HPLC system. Online gradient extraction was conducted with mobile phase at 70 ℃. The separation was performed on Zorbax SB-AQ( 4. 6 mm×150 mm,5 µm) column with 0. 1% formic acid solution-methanol as the mobile phase for gradient elution at 1. 0 mL·min~(-1). The column temperature was 30 ℃,and detection wavelength was set at 260 nm. The results showed that the high and low polar components in Cordyceps could be simultaneously extracted and separated by the developed method. Meanwhile,six high polar compounds( uracil,uridine,thymine,inosine,guanosine and adenosine) and one low polar compound( ergosterol) were identified by comparison with the reference peaks. The established method is rapid,stable and environment friendly,which is helpful to improve the quality evaluation level for Cordyceps.


Assuntos
Cromatografia Líquida de Alta Pressão , Cordyceps/química , Ergosterol/análise , Nucleosídeos/análise
12.
Food Chem ; 297: 124988, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253285

RESUMO

Agaricus blazei, Auricularia fuscosuccinea and Pleurotus albidus mycelia were obtained in solid-state cultivation (SSC), using grains (brown rice, canjica corn and wheat) as raw material. Colonized grain flours were analysed for their nutritional, physical and physico-chemical characteristics and biological activity in vitro. Wheat flour with P. albidus showed higher values for protein (18.34 g/100 g), ergosterol (0.60 mg/g), mycelial biomass (183 mg/g) and total amino acids (58.34 mg/g). Corn flour with A. fuscosuccinea showed the highest total phenolic content (2.38 mg GAE/g), antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) (8.90 µmol TEAC/g) and 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (16.52 µmol TEAC/g) assay. Wheat flour with P. albidus were more effective at inhibiting of pancreatic lipase (74.5%) and of α-glucosidase (98.2%). In conclusion, grains colonized by macrofungi mycelia through SSC can enrich the nutritional value and the biological activity of the flours, which presents a potential for functional foods.


Assuntos
Agaricus/fisiologia , Farinha/análise , Valor Nutritivo , Pleurotus/fisiologia , Aminoácidos/química , Antioxidantes/química , Biomassa , Ergosterol/análise , Lipase/antagonistas & inibidores , Lipase/metabolismo , Oryza/metabolismo , Fenóis/análise , Triticum/metabolismo , Zea mays/metabolismo , alfa-Glucosidases/química , alfa-Glucosidases/metabolismo
13.
Spectrochim Acta A Mol Biomol Spectrosc ; 217: 113-121, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30928836

RESUMO

A new withanolide named as withacoagulin J (1) along with a known withanolide H (2) from Withania coagulans Dunal are reported in this paper. The isolated compounds were elucidated by using 1D-NMR (1H NMR, 13C NMR) and 2D-NMR including homonuclear (COSY, NOESY) and heteronuclear (HSQC, HMBC); along with Mass spectrometry, UV-Visible and IR spectroscopic techniques. The molecular formula based on Fast-Atom Bombardment Mass Spectrometry [FAB-MS (M + 1)] for 1 and 2 were deduced as C28H37O5 and C28H39O6 with m/z values 453.2624 and 471.6041, respectively. The quantum mechanical studies of both compounds are based on DFT calculations. The DFT studies show band gaps of 4.86 and 4.83 eV for 1 and 2, respectively. The band gaps of 1 and 2 reflect high stability and resistivity towards oxidation-reduction reactions. The energies of HOMO and LUMO for compound 1 are -6.11 and -1.25 eV and for compound 2: -6.47 and -1.64 eV respectively. Theoretical and experimental FTIR data closely match for both the compounds which support the high accuracy of the computational protocol selection. Other parameters such as bond lengths, bond angles and dihedral angles for both compounds are also studied.


Assuntos
Ergosterol/análise , Modelos Teóricos , Extratos Vegetais/química , Withania/química , Vitanolídeos/análise , Vitanolídeos/isolamento & purificação , Ergosterol/análogos & derivados , Ergosterol/química , Ergosterol/isolamento & purificação , Teoria Quântica , Vitanolídeos/química
14.
Food Microbiol ; 82: 504-514, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31027812

RESUMO

As a result of the rapidly growing human population, reducing post-harvest crop losses of cereals due to microbial pests has major importance. Plant defensins have the potential to fulfil these demands, being highly specific and efficient antimicrobial agents. Hence, this study aimed to extract and characterise a peptide from cowpea seeds and investigate its antifungal performance. After extraction and partial purification, N-terminal sequencing was used to identify the primary peptide in the extract as cowpea-thionin II. Antifungal activity in vitro was found against Fusarium culmorum (MIC = 50 µg/mL), but Aspergillus niger and Penecillium expansum showed an MIC > 500 µg/mL. The extract was resistant against heat treatment (100 °C, 15 min) but lost its antifungal activity in presence of cations (Na+, K+, Ca2+ and Mg2+, respectively). Membrane permeabilization of fungal hyphae was evident at 25 µg/mL, while induction of oxidative stress only had minor contribution to the antifungal performance. The extract did not induce haemolysis at all concentrations tested (up to 200 µg/mL). Finally, it was successfully used to protect stored wheat grains from fungal spoilage (determined via ergosterol content) when applied at 100 µg/mL. In conclusion, the defensin Cp-thionin II showed the potential for future application as food bio-preservative.


Assuntos
Antifúngicos/farmacologia , Conservantes de Alimentos/farmacologia , Fungos/efeitos dos fármacos , Proteínas de Plantas/farmacologia , Tioninas/farmacologia , Vigna/química , Antifúngicos/química , Antifúngicos/isolamento & purificação , Cátions , Permeabilidade da Membrana Celular/efeitos dos fármacos , Defensinas/química , Defensinas/isolamento & purificação , Defensinas/farmacologia , Grão Comestível/microbiologia , Ergosterol/análise , Ergosterol/metabolismo , Microbiologia de Alimentos , Conservantes de Alimentos/química , Conservantes de Alimentos/isolamento & purificação , Fungos/metabolismo , Fungos/fisiologia , Temperatura Alta , Hifas/efeitos dos fármacos , Hifas/metabolismo , Hifas/fisiologia , Testes de Sensibilidade Microbiana , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Estabilidade Proteica , Sementes/química , Tioninas/química , Tioninas/isolamento & purificação
15.
Food Chem ; 278: 760-766, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-30583439

RESUMO

Mushroom production and consumption is increasing, but high perishability still represents a major commercial drawback. Besides increasing the product shelf-life, conservation processes should be innocuous to consumers. Therefore, the effects of gamma and electron beam radiation on chemical and nutritional composition of fresh samples of Agaricus bisporus Portobello (a highly commercialized species) were assessed. Mushrooms were irradiated at 1, 2 or 5 kGy, and analyzed at different times (0, 4 and 8 days). In general, irradiation type had higher effect than irradiation dose. Gamma irradiation was associated with higher contents in sugars and ergosterol, while the 5 kGy dose, independently of irradiation source, was linked with higher protein levels. Nonetheless, irradiation might represent an effective preservation methodology for Portobello mushrooms, as it was effective in maintaining their chemical profiles (except for minor organic acids and saturated fatty acids) throughout the assayed time intervals.


Assuntos
Agaricus , Irradiação de Alimentos/métodos , Agaricus/química , Agaricus/efeitos da radiação , Relação Dose-Resposta à Radiação , Elétrons , Ergosterol/análise , Armazenamento de Alimentos/métodos , Raios gama , Proteínas de Plantas/análise , Fatores de Tempo
16.
Molecules ; 23(12)2018 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-30501053

RESUMO

With the goal of obtaining a novel bioactive compound with significant antifungal activity, a series of 1,3,4-thiadiazole derivatives (3a⁻3l) were synthesized and characterized. Due to thione-thiol tautomerism in the intermediate compound 2, type of substitution reaction in the final step was determined by two-dimensional (2D) NMR. In vitro antifungal activity of the synthesized compounds was evaluated against eight Candida species. The active compounds 3k and 3l displayed very notable antifungal effects. The probable mechanisms of action of active compounds were investigated using an ergosterol quantification assay. Docking studies on 14-α-sterol demethylase enzyme were also performed to investigate the inhibition potency of compounds on ergosterol biosynthesis. Theoretical absorption, distribution, metabolism, and excretion (ADME) predictions were calculated to seek their drug likeness of final compounds. The results of the antifungal activity test, ergosterol biosynthesis assay, docking study, and ADME predictions indicated that the synthesized compounds are potential antifungal agents, which inhibit ergosterol biosynthesis probably interacting with the fungal 14-α-sterol demethylase.


Assuntos
Antifúngicos/síntese química , Antifúngicos/farmacologia , Tiadiazóis/síntese química , Tiadiazóis/farmacologia , Antifúngicos/química , Candida/efeitos dos fármacos , Ergosterol/análise , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Tiadiazóis/química
17.
Mycologia ; 110(6): 1017-1032, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30481136

RESUMO

Mineral weathering plays an important role in poor-nutrient environments such as mine spoils and tailings. Ectomycorrhizal (ECM) fungi are able to enhance mineral weathering through different mechanisms, thereby increasing the availability of minerals and nutrients to plants. Six ECM fungi (Cadophora finlandia, Cenococcum geophilum, Hebeloma crustuliniforme, Lactarius aurantiosordidus, Paxillus involutes, and Tricholoma scalpturatum) were tested here for their tolerance to biotite-quartz-rich mine tailings. Either solid- or liquid-medium methods were used for in vitro selection of ECM fungi for their ability to grow on mine tailings. ECM fungi were selected based on their mycelial radial growth and metabolite production (ergosterol and low-molecular-mass organic acids, LMMOAs). We found a strong correlation between fungal ergosterol content and mycelial radial growth using the solid-medium method. However, the liquid-medium method was more appropriate for ergosterol synthesis and permitted direct measurement of organic acid production. We found that LMMOAs were exuded by ECM fungi, which solubilized mine tailings for their own growth and nutrition. Finally, we concluded that the ECM fungi C. finlandia and T. scalpturatum are the species most tolerant to tailings and could potentially improve the survival rate, growth, and health of white spruce seedlings planted on biotite mine spoils and tailings.


Assuntos
Silicatos de Alumínio/metabolismo , Biodegradação Ambiental , Biomassa , Meios de Cultura/química , Compostos Ferrosos/metabolismo , Micorrizas/crescimento & desenvolvimento , Micorrizas/metabolismo , Adaptação Fisiológica , Ergosterol/análise , Mineração , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Filogenia , Picea/microbiologia , Raízes de Plantas/microbiologia , Plântula/microbiologia
18.
J Agric Food Chem ; 66(24): 5971-5983, 2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29869500

RESUMO

Pleurotus ostreatus, P. eryngii, and P. nebrodensis were cultivated on nonconventional substrates containing grape marc (GMC) or olive mill byproducts (OMB); wheat straw (WHS) served as control. GMC-based media demonstrated equal/better mushroom productivity than WHS for P. eryngii and P. nebrodensis, while the cultivation performance of P. eryngii was improved in OMB-based media. Both GMC and OMB substrates led to large increase of fruit-bodies content in phenolic acids, resveratrol, triterpenic compounds, and ergosterol; in particular, P. eryngii mushrooms presented significantly more total phenolics and exhibited much higher antioxidant activity (2- to 8-fold increase). Furthermore, substrates containing GMC or OMB presented up to 27% increase in mushroom ß-glucans. Overall, Pleurotus species responded in a different and mostly substrate-specific manner by selectively absorbing organic compounds. Phenolics and squalene content of substrates correlated very well with mushrooms antioxidant activity and ergosterol, respectively; the same was observed for triterpenics' content of substrates and mushrooms.


Assuntos
Olea/química , Pleurotus/crescimento & desenvolvimento , Vitis/química , Resíduos/análise , Meios de Cultura/química , Meios de Cultura/metabolismo , Ergosterol/análise , Hidroxibenzoatos/análise , Olea/metabolismo , Pleurotus/química , Pleurotus/metabolismo , Resveratrol , Estilbenos/análise , Vitis/metabolismo , beta-Glucanas/análise
19.
Molecules ; 23(5)2018 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-29747400

RESUMO

The rise in the number of fungal infections is requiring the rapid development of novel antifungal agents. A new polyoxovanadate functionalized by Zn-fluconazole coordination complexes, Zn3(FLC)6V10O28·10H2O (ZnFLC) (FLC = fluconazole) has been synthesized and evaluated for in vitro antifungal against Candida species. The identity of ZnFLC were confirmed by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. The antifungal activities of ZnFLC was screened in 19 Candida species strains using the microdilution checkerboard technique. The minimum inhibitory concentration (MIC80) value of ZnFLC is 4 µg/mL on the azole-resistant clinical isolates of C. albicans HL973, which is lower than the positive control, FLC. The mechanism of ZnFLC against C. albicans HL973 showed that ZnFLC damaged the fungal cell membrane and reduced the ergosterol content. The expression of ERG1, ERG7, ERG11 ERG27, and ERG28, which have effects on the synthesis of ergosterol, were all significantly upregulated by ZnFLC.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Complexos de Coordenação/farmacologia , Fluconazol/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Vanadatos/farmacologia , Zinco/química , Antifúngicos/química , Vias Biossintéticas/genética , Candida/genética , Candida/crescimento & desenvolvimento , Candida/isolamento & purificação , Complexos de Coordenação/química , Ergosterol/análise , Ergosterol/biossíntese , Fluconazol/química , Genes Fúngicos , Testes de Sensibilidade Microbiana , Microscopia de Fluorescência , Vanadatos/química
20.
J Microbiol Methods ; 148: 49-54, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29580983

RESUMO

Ergosterol, total phospholipid fatty acid (PLFA) and linoleic acid (18:2n-6) have all been used to determine fungal growth. This paper compares these methods to assess the growth of four different saprotrophic fungal species during solid state cultivation using a wheat straw substrate that have not been compared or measured previously. Ergosterol production appeared to track the mycelia growth well but its production differed considerably between fungi. This means that a specific conversion factor needs to be determined and applied for any given fungus. In comparison, measurements of total PLFA and linoleic acid only showed promise for determining the growth of Postia placenta due to the positive correlation with ergosterol measurements. In contrast, the other fungi tested (Phanerochaete chrysosporium, Serpula lacrymans and Schizophyllum commune) showed either no correlation or in some cases a negative correlation using this assay. The novel findings highlight the variation in fungal fatty acid between species, culture conditions and durations of incubation; suggesting that measurement of linoleic acid is only usable in specific cases. These findings provide important consideration for the study of fungi growing in solid substrates and suggest that the use of PLFA might bias diversity indices.


Assuntos
Ergosterol/análise , Fungos/química , Fungos/crescimento & desenvolvimento , Técnicas Microbiológicas/métodos , Fosfolipídeos/análise , Caules de Planta/microbiologia , Triticum/microbiologia , Ácido Linoleico/análise , Phanerochaete , Schizophyllum
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...