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1.
Molecules ; 26(15)2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34361632

RESUMO

The present study focuses on the biological synthesis, characterization, and antibacterial activities of silver nanoparticles (AgNPs) using extracellular extracts of Aspergillus japonicus PJ01.The optimal conditions of the synthesis process were: 10 mL of extracellular extracts, 1 mL of AgNO3 (0.8 mol/L), 4 mL of NaOH solution (1.5 mol/L), 30 °C, and a reaction time of 1 min. The characterizations of AgNPs were tested by UV-visible spectrophotometry, zeta potential, scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric (TG) analyses. Fourier transform infrared spectroscopy (FTIR) analysis showed that Ag+ was reduced by the extracellular extracts, which consisted chiefly of soluble proteins and reducing sugars. In this work, AgNO3 concentration played an important role in the physicochemical properties and antibacterial properties of AgNPs. Under the AgNO3 concentration of 0.2 and 0.8 mol/L, the diameters of AgNPs were 3.8 ± 1.1 and 9.1 ± 2.9 nm, respectively. In addition, smaller-sized AgNPs showed higher antimicrobial properties, and the minimum inhibitory concentration (MIC) values against both E. coli and S. aureus were 0.32 mg/mL.


Assuntos
Antibacterianos , Aspergillus/metabolismo , Química Verde/métodos , Nanopartículas Metálicas/química , Prata/química , Antibacterianos/química , Antibacterianos/farmacologia
2.
Molecules ; 26(15)2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34361698

RESUMO

Patulin (PAT) and citrinin (CTN) are the most common mycotoxins produced by Penicillium and Aspergillus species and are often associated with fruits and fruit by-products. Hence, simple and reliable methods for monitoring these toxins in foodstuffs are required for regular quality assessment. In this study, we aimed to establish a cost-effective method for detection and quantification of PAT and CTN in pome fruits, such as apples and pears, using high-performance liquid chromatography (HPLC) coupled with spectroscopic detectors without the need for any clean-up steps. The method showed good performance in the analysis of these mycotoxins in apple and pear fruit samples with recovery ranges of 55-97% for PAT and 84-101% for CTN, respectively. The limits of detection (LOD) of PAT and CTN in fruits were 0.006 µg/g and 0.001 µg/g, while their limits of quantification (LOQ) were 0.018 µg/g and 0.003 µg/g, respectively. The present findings indicate that the newly developed HPLC method provides rapid and accurate detection of PAT and CTN in fruits.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Citrinina/análise , Contaminação de Alimentos/análise , Frutas/química , Malus/química , Patulina/análise , Pyrus/química , Aspergillus/metabolismo , Cromatografia Líquida de Alta Pressão/economia , Análise Custo-Benefício , Confiabilidade dos Dados , Qualidade dos Alimentos , Limite de Detecção , Penicillium/metabolismo , Fatores de Tempo
3.
Molecules ; 26(11)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199488

RESUMO

In December 2020, the U.K. authorities reported to the World Health Organization (WHO) that a new COVID-19 variant, considered to be a variant under investigation from December 2020 (VUI-202012/01), was identified through viral genomic sequencing. Although several other mutants were previously reported, VUI-202012/01 proved to be about 70% more transmissible. Hence, the usefulness and effectiveness of the newly U.S. Food and Drug Administration (FDA)-approved COVID-19 vaccines against these new variants are doubtfully questioned. As a result of these unexpected mutants from COVID-19 and due to lack of time, much research interest is directed toward assessing secondary metabolites as potential candidates for developing lead pharmaceuticals. In this study, a marine-derived fungus Aspergillus terreus was investigated, affording two butenolide derivatives, butyrolactones I (1) and III (2), a meroterpenoid, terretonin (3), and 4-hydroxy-3-(3-methylbut-2-enyl)benzaldehyde (4). Chemical structures were unambiguously determined based on mass spectrometry and extensive 1D/2D NMR analyses experiments. Compounds (1-4) were assessed for their in vitro anti-inflammatory, antiallergic, and in silico COVID-19 main protease (Mpro) and elastase inhibitory activities. Among the tested compounds, only 1 revealed significant activities comparable to or even more potent than respective standard drugs, which makes butyrolactone I (1) a potential lead entity for developing a new remedy to treat and/or control the currently devastating and deadly effects of COVID-19 pandemic and elastase-related inflammatory complications.


Assuntos
4-Butirolactona/análogos & derivados , Antialérgicos/química , Anti-Inflamatórios/química , Aspergillus/química , SARS-CoV-2/enzimologia , Proteínas da Matriz Viral/antagonistas & inibidores , 4-Butirolactona/química , 4-Butirolactona/isolamento & purificação , 4-Butirolactona/metabolismo , Antialérgicos/metabolismo , Anti-Inflamatórios/metabolismo , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Sítios de Ligação , COVID-19/patologia , COVID-19/virologia , Domínio Catalítico , Humanos , Elastase de Leucócito/antagonistas & inibidores , Elastase de Leucócito/metabolismo , Espectroscopia de Ressonância Magnética , Conformação Molecular , Simulação de Acoplamento Molecular , Neutrófilos/enzimologia , SARS-CoV-2/isolamento & purificação , Água do Mar/microbiologia , Proteínas da Matriz Viral/metabolismo
4.
Molecules ; 26(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209863

RESUMO

The fungal strain was isolated from a soil sample collected in Giza province, Egypt, and was identified as Aspergillus ochraceopetaliformis based on phenotypic and genotypic data. The ethyl acetate extract of the fungal strain exhibited promising activity levels against several pathogenic test organisms and through a series of 1H NMR guided chromatographic separations, a new α-pyrone-C-lyxofuranoside (1) along with four known compounds (2-5) were isolated. The planar structure of the new metabolite was elucidated by detailed analysis of its 1D/2D NMR and HRMS/IR/UV spectroscopic data, while the relative configuration of the sugar moiety was determined by a combined study of NOESY and coupling constants data, with the aid of theoretical calculations. The structures of the known compounds-isolated for the first time from A. ochraceopetaliformis-were established by comparison of their spectroscopic data with those in the literature. All isolated fungal metabolites were evaluated for their antibacterial and antifungal activities against six Gram-positive and Gram-negative bacteria as well as against three human pathogenic fungi.


Assuntos
Antibacterianos , Aspergillus/metabolismo , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Positivas/crescimento & desenvolvimento , Microbiologia do Solo , Antibacterianos/isolamento & purificação , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Aspergillus/isolamento & purificação
5.
Molecules ; 26(14)2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34299514

RESUMO

Aspergillus is one of the most diverse genera, and it is chemically profound and known to produce many biologically active secondary metabolites. In the present study, a new aspochalasin H1 (1), together with nine known compounds (2-10), were isolated from a Hawaiian plant-associated endophytic fungus Aspergillus sp. FT1307. The structures were elucidated using nuclear magnetic resonance (NMR) (1H, 1H-1H COSY, HSQC, HMBC, ROESY and 1D NOE), high-resolution electrospray ionization mass spectroscopy (HRESIMS), and comparisons with the reported literature. The absolute configuration of the new compound was established by electronic circular dichroism (ECD) in combination with NMR calculations. The new compound contains an epoxide moiety and an adjacent trans-diol, which has not been reported before in the aspochalasin family. The antibacterial screening of the isolated compounds was carried out against pathogenic bacteria (Staphylococcus aureus, Methicillin-resistant S. aureus and Bacillus subtilis). The antiproliferative activity of compounds 1-10 was evaluated against human breast cancer cell lines (MCF-7 and T46D) and ovarian cancer cell lines (A2780).


Assuntos
Aspergillus/metabolismo , Boraginaceae/microbiologia , Citocalasinas/farmacologia , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Dicroísmo Circular , Feminino , Hawaii , Humanos , Células MCF-7 , Espectroscopia de Ressonância Magnética/métodos , Neoplasias Ovarianas/tratamento farmacológico
6.
Sci Rep ; 11(1): 9347, 2021 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-33931710

RESUMO

A deep-sea fungus Aspergillus sydowii BOBA1 isolated from marine sediment at a depth of 3000 m was capable of degrading spent engine (SE) oil. The response of immobilized fungi towards degradation at elevated pressure was studied in customized high pressure reactors without any deviation in simulating in situ deep-sea conditions. The growth rate of A. sydowii BOBA1 in 0.1 MPa was significantly different from the growth at 10 MPa pressure. The degradation percentage reached 71.2 and 82.5% at atmospheric and high pressure conditions, respectively, within a retention period of 21 days. The complete genome sequence of BOBA1 consists of 38,795,664 bp in size, comprises 2582 scaffolds with predicted total coding genes of 18,932. A total of 16,247 genes were assigned with known functions and many families found to have a potential role in PAHs and xenobiotic compound metabolism. Functional genes controlling the pathways of hydrocarbon and xenobiotics compound degrading enzymes such as dioxygenase, decarboxylase, hydrolase, reductase and peroxidase were identified. The spectroscopic and genomic analysis revealed the presence of combined catechol, gentisate and phthalic acid degradation pathway. These results of degradation and genomic studies evidenced that this deep-sea fungus could be employed to develop an eco-friendly mycoremediation technology to combat the oil polluted marine environment. This study expands our knowledge on piezophilic fungi and offer insight into possibilities about the fate of SE oil in deep-sea.


Assuntos
Aspergillus/genética , Aspergillus/metabolismo , Biodegradação Ambiental , Genoma Fúngico , Sedimentos Geológicos/microbiologia , Peroxidases/metabolismo , Petróleo/metabolismo , Aspergillus/crescimento & desenvolvimento , Petróleo/microbiologia , Hidrocarbonetos Policíclicos Aromáticos/metabolismo
7.
Food Chem ; 358: 129848, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33933981

RESUMO

Autumn green tea (AT) has poor taste quality for its strong astringency. This study aims to improve the taste quality as well as the aroma of AT by Eurotium cristatum (MF800948) fermentation and to produce a fermented autumn green tea (FT). Results showed that the aroma quality of AT was improved, and the content of terpene alcohols that impart characteristic flowery aroma to FT significantly increased. The umami intensity of FT was comparable to that of AT while the astringency tasted much weaker mainly due to the oxidation of the catechins. The results also confirmed that theabrownins exhibited strong umami taste, not astringent taste. Finally, a metabolic map was analyzed to show the effect of E. cristatum (MF800948) on the quality of AT, and to visualize the changes of differential compounds in AT and FT. The work provides insights into the quality improvement of autumn green tea.


Assuntos
Aspergillus/metabolismo , Fermentação , Paladar , Chá/química , Catequina/análise , Manipulação de Alimentos , Odorantes , Estações do Ano , Terpenos/análise
8.
Int J Mol Sci ; 22(9)2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33926042

RESUMO

The control of the fungal contamination on crops is considered a priority by the sanitary authorities of an increasing number of countries, and this is also due to the fact that the geographic areas interested in mycotoxin outbreaks are widening. Among the different pre- and post-harvest strategies that may be applied to prevent fungal and/or aflatoxin contamination, fungicides still play a prominent role; however, despite of countless efforts, to date the problem of food and feed contamination remains unsolved, since the essential factors that affect aflatoxins production are various and hardly to handle as a whole. In this scenario, the exploitation of bioactive natural sources to obtain new agents presenting novel mechanisms of action may represent a successful strategy to minimize, at the same time, aflatoxin contamination and the use of toxic pesticides. The Aflatox® Project was aimed at the development of new-generation inhibitors of aflatoxigenic Aspergillus spp. proliferation and toxin production, through the modification of naturally occurring molecules: a panel of 177 compounds, belonging to the thiosemicarbazones class, have been synthesized and screened for their antifungal and anti-aflatoxigenic potential. The most effective compounds, selected as the best candidates as aflatoxin containment agents, were also evaluated in terms of cytotoxicity, genotoxicity and epi-genotoxicity to exclude potential harmful effect on the human health, the plants on which fungi grow and the whole ecosystem.


Assuntos
Aflatoxinas/química , Aflatoxinas/isolamento & purificação , Aspergillus flavus/química , Aflatoxinas/toxicidade , Antifúngicos/farmacologia , Aspergillus/metabolismo , Aspergillus/patogenicidade , Aspergillus flavus/isolamento & purificação , Aspergillus flavus/metabolismo , Aspergillus flavus/patogenicidade , Produtos Agrícolas/microbiologia , Ecossistema , Contaminação de Alimentos/prevenção & controle , Fungos/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Humanos , Micotoxinas/toxicidade , Tiossemicarbazonas/química
9.
Mar Drugs ; 19(3)2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33802820

RESUMO

Six new prenylated indole diketopiperazine alkaloids, asperthrins A-F (1-6), along with eight known analogues (7-14), were isolated from the marine-derived endophytic fungus Aspergillus sp. YJ191021. Their planar structures and absolute configurations were elucidated by HR-ESI-MS, 1D/2D NMR data, and time-dependent density functional theory (TDDFT)/ECD calculation. The isolated compounds were assayed for their inhibition against three agricultural pathogenic fungi, four fish pathogenic bacteria, and two agricultural pathogenic bacteria. Compound 1 exhibited moderate antifungal and antibacterial activities against Vibrioanguillarum, Xanthomonas oryzae pv. Oryzicola, and Rhizoctoniasolani with minimal inhibitory concentration (MIC) values of 8, 12.5, and 25 µg/mL, respectively. Furthermore, 1 displayed notable anti-inflammatory activity with IC50 value of 1.46 ± 0.21 µM in Propionibacteriumacnes induced human monocyte cell line (THP-1).


Assuntos
Antibacterianos/farmacologia , Anti-Inflamatórios/farmacologia , Antifúngicos/farmacologia , Aspergillus/metabolismo , Dicetopiperazinas/farmacologia , Alcaloides Indólicos/farmacologia , Antibacterianos/isolamento & purificação , Anti-Inflamatórios/isolamento & purificação , Antifúngicos/isolamento & purificação , Dicetopiperazinas/isolamento & purificação , Humanos , Alcaloides Indólicos/isolamento & purificação , Interleucina-1beta/imunologia , Estrutura Molecular , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Monócitos/microbiologia , Propionibacterium acnes/imunologia , Relação Estrutura-Atividade , Células THP-1
10.
J Agric Food Chem ; 69(16): 4840-4848, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33856211

RESUMO

Biocontrol to combat the menace of Aspergillus flavus has gained considerable attention. However, the molecular mechanisms of A. flavus 's response to antagonism biotic stress are poorly deciphered. Here, we discovered that A. flavus switches an adaptive metabolic reprogramming to ensure its adversity survival by multiomics analyses (including four omics platform). Antifungal "weapons" lipopeptides and antibacterial metabolites of imizoquin were identified. The central metabolism fluxes were significantly depleted but the expressions of most corresponding genes were considerably increased in A. flavus. Secondary metabolism that does not contribute to stress was markedly suppressed. In contrast, A. flavus antibacterial "weapon arsenal" was activated to occupy an ecological niche. Our results revealed that interlinked mitochondrial central metabolism and secondary metabolism are central to A. flavus antagonism biotic stress response. This discovery contributes to the targeted design of biocontrol agents and smart regularization of rhizosphere microbiome homeostasis to realize long-term fungi pathogen control and mitigation mycotoxin contamination.


Assuntos
Aflatoxinas , Aspergillus flavus , Aflatoxinas/metabolismo , Aspergillus/metabolismo , Aspergillus flavus/metabolismo , Fungos/metabolismo , Metabolismo Secundário
11.
Toxins (Basel) ; 13(3)2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33808964

RESUMO

Aflatoxins (AFs) are among the most harmful fungal secondary metabolites imposing serious health risks on both household animals and humans. The more frequent occurrence of aflatoxins in the feed and food chain is clearly foreseeable as a consequence of the extreme weather conditions recorded most recently worldwide. Furthermore, production parameters, such as unadjusted variety use and improper cultural practices, can also increase the incidence of contamination. In current aflatoxin control measures, emphasis is put on prevention including a plethora of pre-harvest methods, introduced to control Aspergillus infestations and to avoid the deleterious effects of aflatoxins on public health. Nevertheless, the continuous evaluation and improvement of post-harvest methods to combat these hazardous secondary metabolites are also required. Already in-use and emerging physical methods, such as pulsed electric fields and other nonthermal treatments as well as interventions with chemical agents such as acids, enzymes, gases, and absorbents in animal husbandry have been demonstrated as effective in reducing mycotoxins in feed and food. Although most of them have no disadvantageous effect either on nutritional properties or food safety, further research is needed to ensure the expected efficacy. Nevertheless, we can envisage the rapid spread of these easy-to-use, cost-effective, and safe post-harvest tools during storage and food processing.


Assuntos
Aflatoxinas/análise , Ração Animal/microbiologia , Aspergillus/metabolismo , Proteção de Cultivos , Produtos Agrícolas/microbiologia , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Aflatoxinas/toxicidade , Animais , Cadeia Alimentar , Manipulação de Alimentos , Humanos , Medição de Risco , Metabolismo Secundário
12.
Toxins (Basel) ; 13(4)2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33807312

RESUMO

Ochratoxin A (OTA) usually contaminates agricultural products such as grapes, oatmeal, coffee and spices. Light was reported as an effective strategy to control spoilage fungi and mycotoxins. This research investigated the effects of light with different wavelengths on the growth and the production of OTA in Aspergillus ochraceus and Aspergillus carbonarius. The results showed that the growth of both fungi were extremely inhibited by UV-B. Short-wavelength (blue, violet) significantly inhibited the production of OTA in both fungi, while the inhibitory effect of white was only demonstrated on A. ochraceus. These results were supported by the expression profiles of OTA biosynthetic genes of A. ochraceus and A. carbonarius. To clarify, the decrease in OTA production is induced by inhibition or degradation; therefore, the degradation of OTA under different wavelengths of light was tested. Under UV-B, the degradation rate of 10 µg/mL OTA standard pure-solution samples could reach 96.50% in 15 days, and the degradation effect of blue light was relatively weak. Furthermore, infection experiments of pears showed that the pathogenicity of both fungi was significantly decreased under UV-B radiation. Thus, these results suggested that light could be used as a potential target for strategies in the prevention and control of ochratoxigenic fungi.


Assuntos
Aspergillus ochraceus/efeitos da radiação , Aspergillus/efeitos dos fármacos , Frutas/microbiologia , Ocratoxinas/biossíntese , Pyrus/microbiologia , Raios Ultravioleta , Aspergillus/genética , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Aspergillus ochraceus/genética , Aspergillus ochraceus/crescimento & desenvolvimento , Aspergillus ochraceus/metabolismo , Microbiologia de Alimentos , Regulação Fúngica da Expressão Gênica , Fatores de Tempo
13.
mBio ; 12(2)2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33727355

RESUMO

Tip-growing fungal cells maintain cell polarity at the apical regions and elongate by de novo synthesis of the cell wall. Cell polarity and tip growth rate affect mycelial morphology. However, it remains unclear how both features act cooperatively to determine cell shape. Here, we investigated this relationship by analyzing hyphal tip growth of filamentous fungi growing inside extremely narrow 1 µm-width channels of microfluidic devices. Since the channels are much narrower than the diameter of hyphae, any hypha growing through the channel must adapt its morphology. Live-cell imaging analyses revealed that hyphae of some species continued growing through the channels, whereas hyphae of other species often ceased growing when passing through the channels, or had lost apical polarity after emerging from the other end of the channel. Fluorescence live-cell imaging analyses of the Spitzenkörper, a collection of secretory vesicles and polarity-related proteins at the hyphal tip, in Neurospora crassa indicates that hyphal tip growth requires a very delicate balance of ordered exocytosis to maintain polarity in spatially confined environments. We analyzed the mycelial growth of seven fungal species from different lineages, including phytopathogenic fungi. This comparative approach revealed that the growth defects induced by the channels were not correlated with their taxonomic classification or with the width of hyphae, but, rather, correlated with the hyphal elongation rate. This report indicates a trade-off between morphological plasticity and velocity in mycelial growth and serves to help understand fungal invasive growth into substrates or plant/animal cells, with direct impact on fungal biotechnology, ecology, and pathogenicity.IMPORTANCE Cell morphology, which is controlled by polarity and growth, is fundamental for all cellular functions. However how polarity and growth act cooperatively to control cell shape remains unclear. Here we investigated their relationship by analyzing hyphal tip growth of filamentous fungi growing inside extremely narrow 1 µm-width channels of microfluidic devices. We found that most fast growing hyphae often lost the cell polarity after emerging from the channels, whereas slow growing hyphae retained polarity and continued growing, indicating a trade-off between plasticity and velocity in mycelial growth. These results serve to understand fungal invasive growth into substrates or plant/animal cells, with direct impact on fungal biotechnology, ecology and pathogenicity.


Assuntos
Polaridade Celular , Fungos/crescimento & desenvolvimento , Hifas/citologia , Hifas/crescimento & desenvolvimento , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Citoplasma/metabolismo , Proteínas Fúngicas/metabolismo , Fungos/metabolismo , Microtúbulos , Neurospora crassa/crescimento & desenvolvimento , Neurospora crassa/metabolismo , Vesículas Secretórias/metabolismo
14.
Sci Rep ; 11(1): 6808, 2021 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-33762586

RESUMO

Aspergillus species are emerging causative agents of non-dermatophyte mold onychomycosis. In this study, 48 Aspergillus isolates were obtained from patients with onychomycosis in Mashhad, Iran, during 2015-2018. The aim is to identify the Aspergillus isolates to the species level by using partial calmodulin and beta-tubulin gene sequencing and MALDI-TOF MS, and to evaluate their in vitro susceptibility to ten antifungal drugs: terbinafine, itraconazole, voriconazole, posaconazole, ravuconazole, isavuconazole, caspofungin, micafungin, anidulafungin and amphotericin B according to CLSI M38-A3. Our results indicate that A.flavus (n = 38, 79%) is the most common Aspergillus species causing onychomycosis in Mashhad, Iran. Other detected species were A. terreus (n = 3), A. tubingensis (n = 2), A. niger (n = 1), A. welwitschiae (n = 1), A. minisclerotigenes (n = 1), A. citrinoterreus (n = 1) and A. ochraceus (n = 1). Aspergillus flavus, A. terreus and A. niger isolates were correctly identified at the species level by MALDI-TOF MS, while all cryptic species were misidentified. In conclusion, A. flavus is the predominant Aspergillus species causing onychomycosis due to Aspergillus spp. in Mashhad, Iran. MALDI-TOF MS holds promise as a fast and accurate identification tool, particularly for common Aspergillus species. It is important that the current database of reference spectra, representing different Aspergillus species is expanded to increase the precision of the species-level identification. Terbinafine, posaconazole and echinocandins were in vitro most active against the studies Aspergillus isolates and terbinafine could be the first choice for treatment of onychomycosis due to Aspergillus.


Assuntos
Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Onicomicose/patologia , Antifúngicos/uso terapêutico , Aspergillus/isolamento & purificação , Aspergillus/metabolismo , Calmodulina/genética , Proteínas Fúngicas/genética , Humanos , Irã (Geográfico) , Testes de Sensibilidade Microbiana , Nitrilas/farmacologia , Nitrilas/uso terapêutico , Onicomicose/tratamento farmacológico , Onicomicose/microbiologia , Piridinas/farmacologia , Piridinas/uso terapêutico , Análise de Sequência de DNA/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Triazóis/farmacologia , Triazóis/uso terapêutico , Tubulina (Proteína)/genética , Voriconazol/farmacologia , Voriconazol/uso terapêutico
15.
Bioorg Chem ; 110: 104822, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33770672

RESUMO

Thirteen alkaloids, which include three new diketopiperazines, namely, 3-hydroxyprotuboxepin K (4), 3,15-dehydroprotuboxepin K (5), and versiamide A (6), together with ten known alkaloid derivatives (1-3 and 7-13), were isolated from the marine red algal-derived fungus Aspergillus creber EN-602. Versiamide A (6) represents the first example of a naturally occurring quinazolinone alkaloid with a diketopiperazine ring that is derived from phenylalanine (Phe) and leucine (Leu). The structures of these compounds were elucidated by detailed interpretation of their 1D/2D NMR spectroscopic and mass spectrometric data, while the absolute configurations of compounds 1-6 were established on the basis of X-ray crystallographic analysis and time-dependent density functional (TDDFT) calculations of the ECD spectra. Compounds 1, 2, and 4 exhibited inhibitory activity against the angiotensin converting enzyme (ACE) with IC50 values of 11.2, 16.0, and 22.4 µM, respectively, and compounds 5 and 6 inhibited various aquatic bacteria with MIC values that ranged from 8 to 64 µg/mL. The intermolecular interactions and potential binding sites between compounds 1-6 and ACE were investigated via molecular docking simulations.


Assuntos
Alcaloides/farmacologia , Aspergillus/química , Inibidores Enzimáticos/farmacologia , Peptidil Dipeptidase A/metabolismo , Rodófitas/microbiologia , Alcaloides/biossíntese , Alcaloides/química , Aspergillus/metabolismo , Cristalografia por Raios X , Teoria da Densidade Funcional , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-Atividade
16.
J Basic Microbiol ; 61(5): 443-458, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33783000

RESUMO

This study describes for the first time the purification and characterization of a glucoamylase from Aspergillus wentii (strain PG18), a species of the Aspergillus genus Cremei section. Maximum enzyme production (∼3.5 U/ml) was obtained in submerged culture (72 h) with starch as the carbon source, at 25°C, and with orbital agitation (100 rpm). The enzyme was purified with one-step molecular exclusion chromatography. The 86 kDa purified enzyme hydrolyzed starch in a zymogram and had activity against p-nitrophenyl α- d-glucopyranoside. The optimal enzyme pH and temperature were 5.0 and 60°C (at pH 5.0), respectively. The Tm of the purified enzyme was 60°C, at pH 7.0. The purified glucoamylase had a KM for starch of 1.4 mg/ml and a Vmax of 0.057 mg/min of hydrolyzed starch. Molybdenum activated the purified enzyme, and sodium dodecyl sulfate inhibited it. A thin layer chromatography analysis revealed glucose as the enzyme's main starch hydrolysis product. An enzyme's peptide sequence was obtained by mass spectrometry and used to retrieve a glucoamylase within the annotated genome of A. wentii v1.0. An in silico structural model revealed a N-terminal glycosyl hydrolases family 15 (GH15) domain, which is ligated by a linker to a C-terminal carbohydrate-binding module (CBM) from the CBM20 family.


Assuntos
Aspergillus/enzimologia , Aspergillus/metabolismo , Glucana 1,4-alfa-Glucosidase/química , Glucana 1,4-alfa-Glucosidase/metabolismo , Aspergillus/genética , Cromatografia em Gel , Cromatografia em Camada Delgada , Simulação por Computador , Genoma Fúngico , Glucana 1,4-alfa-Glucosidase/análise , Glucana 1,4-alfa-Glucosidase/genética , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Amido/metabolismo , Especificidade por Substrato , Temperatura
17.
Ann Agric Environ Med ; 28(1): 72-80, 2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33775070

RESUMO

INTRODUCTION: Mycotoxins - secondary mould metabolites with undesirable effects for humans - are common in the environment. These toxins are mainly produced by fungi of the genera Penicilium, Aspergillus and Fusarium. OBJECTIVE: The aim of this study was to evaluate the applicability of various sources of antioxidants (blueberries lyophilisate, cranberries lyophilisate and cinnamon powder), at 5 different concentrations (3%, 5%, 10%, 20%, 30%), to inhibit the formation of mycotoxins during the storage of cereal products. Analysed cereal samples included selected cereal grains, bran and cereal products intended for consumption by children. RESULTS: The results showed that supplementation of oat brans with the highest concentrations of blueberry lyophilisate resulted in a significant decrease in the mycotoxins levels; specifically: 20% concentration reduced the level of HT-2 toxin by 10.7% in one sample, while 30% concentration reduced it by 9.4% and 17.4% in 2 other samples. A similar result was measured for oat bran samples supplemented with the cranberry lyophilisate: specifically, 20% concentration significantly reduced the level of HT-2 toxin by 10.6% in one sample, while 30% concentration reduced it by an average of 18.0% ± 6,0% in 5 other samples. Finally, cinnamon powder supplementation caused a significant reduction in HT-2 levels in all stored samples, even at its lowest concentration. 30% supplementation resulted in HT-2 reduction in cereal samples by 67.1% - 76.1%, in wheat bran samples by 57.5% - 69.2%, in oat bran samples by 83.4% - 87.0% and by 55.0% - 100% in samples of cereal products intended for consumption by children. CONCLUSIONS: Natural products used in the experiment (blueberry, cranberry, cinnamon) inhibited the formation of mycotoxins from the group of trichothecenes.


Assuntos
Mirtilos Azuis (Planta)/química , Cinnamomum zeylanicum/química , Grão Comestível/química , Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Extratos Vegetais/farmacologia , Tricotecenos/análise , Vaccinium macrocarpon/química , Aspergillus/efeitos dos fármacos , Aspergillus/metabolismo , Grão Comestível/microbiologia , Contaminação de Alimentos/análise , Contaminação de Alimentos/prevenção & controle , Conservantes de Alimentos/análise , Armazenamento de Alimentos , Fusarium/efeitos dos fármacos , Fusarium/metabolismo , Tricotecenos/metabolismo
18.
Int J Food Microbiol ; 344: 109113, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33652337

RESUMO

Ochratoxins are a group of mycotoxins that frequently occur as contaminants in agricultural commodities and foods, including dry-cured meats and cheeses. The fungus Aspergillus westerdijkiae is frequently isolated from aged foods and can produce ochratoxin A (OTA). However, individual strains of the fungus can have one of two OTA production phenotypes (chemotypes): OTA production and OTA nonproduction. Monitoring and early detection of OTA-producing fungi in food are the most effective strategies to manage OTA contamination. Therefore, we examined genome sequence data from five A. westerdijkiae strains isolated from the surface of cheese from southern Italy to identify genetic markers indicative of the twoOTA chemotypes. This analysis revealed a naturally occurring deletion of the OTA regulatory gene, otaR, in an OTA-nonproducing isolate.We used this information to design a polymerase chain reaction (PCR) method that could identify A. westerdijkiae and distinguish between the two OTA chemotypes. In this method, the PCR primers were complementary to conserved sequences flanking otaR and yielded different-sized amplicons from strains with the different chemotypes. The primers did not yield ota-region-specific amplicons from other OTA-producing species. Because the method is specific to A. westerdijkiae and can distinguish between the two OTA chemotypes, it has potential to significantly improve OTA monitoring programs.


Assuntos
Aspergillus/metabolismo , Queijo/microbiologia , Alimentos em Conserva/microbiologia , Carne/microbiologia , Ocratoxinas/biossíntese , Reação em Cadeia da Polimerase/métodos , Aspergillus/genética , Aspergillus/isolamento & purificação , Primers do DNA/genética , Contaminação de Alimentos/análise , Itália
19.
Int J Food Microbiol ; 344: 109111, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33676331

RESUMO

Currants are prone to contamination by ochratoxin during cultivation, processing and storage conditions. Saccharomyces cerevisiae is considered to be among the main species of grape yeast flora able to control antagonistic fungi. In this study, the potential of S. cerevisiae Y33 was investigated to inhibit the growth of several fungal species indigenous to the microbiota of grapes. Moreover, the efficacy of this yeast species was investigated to inhibit OTA by toxin producing fungi both in vitro and in situ. For this purpose thirty-five different fungal species, belonging to the genera Aspergillus, Penicillium, Cladosporium, Fusarium and Alternaria interacted in vitro with S. cerevisiae on Malt Extract agar plates, stored at 25 °C for 14 days. Results showed that the highest OTA producer A. carbonarius F71 was inhibited more than 99% from day 7, in contrast to A. niger strains that presented enhanced OTA production at day 14 due to interaction with S. cerevisiae Y33. Additionally, the antifungal potential of the selected yeast was also studied in situ on currants subjected to different treatments and stored at 25 °C for 28 days. Microbiological analysis was undertaken for the enumeration of the bacterial and fungal flora, together with OTA determination at 7 and 21 days. To quantify A. carbonarius on all treated currant samples, molecular analysis with Real Time PCR was employed. A standard curve was prepared with A. carbonarius DNA. The efficiency of the curve was estimated to 10.416, the slope to -3.312 and the range of haploid genome that could be estimated was from 1.05 to 105∙105. The amount of A. carbonarius DNA in all treated currants samples, where the fungus was positively detected, ranged from as low as 0.08 to 562 ng DNA/g currants. The antifungal activity of S. cerevisiae Y33 was observed in all studied cases, causing inhibition of fungal growth and OTA production.


Assuntos
Antibiose/fisiologia , Ocratoxinas/biossíntese , Ribes/microbiologia , Saccharomyces cerevisiae/patogenicidade , Alternaria/crescimento & desenvolvimento , Alternaria/metabolismo , Antifúngicos/metabolismo , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Cladosporium/crescimento & desenvolvimento , Cladosporium/metabolismo , Frutas/microbiologia , Fusarium/crescimento & desenvolvimento , Fusarium/metabolismo , Penicillium/crescimento & desenvolvimento , Penicillium/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Saccharomyces cerevisiae/genética , Fermento Seco
20.
J Appl Microbiol ; 131(3): 1193-1211, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33559270

RESUMO

AIMS: To identify the metabolites produced by the endophytic fungus, Aspergillus terreus and to explore the anti-viral activity of the identified metabolites against the pandemic disease COVID-19 in-silico. METHODS AND RESULTS: Herein, we reported the isolation of A. terreus, the endophytic fungus associated with soybean roots, which is then subcultured using OSMAC approach in five different culture media. Analytical analysis of media ethylacetate extracts using liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) was carried out. Furthermore, the obtained LC-MS data were statistically processed with MetaboAnalyst 4.0. Molecular docking studies were performed for the dereplicated metabolites against COVID-19 main protease (Mpro ). Metabolomic profiling revealed the presence of 18 compounds belonging to different chemical classes. Quinones, polyketides and isocoumarins were the most abundant classes. Multivariate analysis revealed that potato dextrose broth and modified potato dextrose broth are the optimal media for metabolites production. Molecular docking studies declared that the metabolites, Aspergillide B1 and 3a-Hydroxy-3, 5-dihydromonacolin L showed the highest binding energy scores towards COVID-19 main protease (Mpro ) (-9·473) and (-9·386), respectively, and they interact strongly with the catalytic dyad (His41 and Cys145) amino acid residues of Mpro . CONCLUSIONS: A combination of metabolomics and in-silico approaches have allowed a shorter route to search for anti-COVID-19 natural products in a shorter time. The dereplicated metabolites, aspergillide B1 and 3α-Hydroxy-3, 5-dihydromonacolin L were found to be potent anti-COVID-19 drug candidates in the molecular docking study. SIGNIFICANCE AND IMPACT OF THE STUDY: This study revealed that the endophytic fungus, A. terreus can be considered as a potential source of natural bioactive products. In addition to, the possibility of developing the metabolites, aspergillide B1 and 3α-Hydroxy-3, 5-dihydromonacolin L to be used as phytopharmaceuticals for the management of COVID-19.


Assuntos
Aspergillus , COVID-19 , Simulação de Acoplamento Molecular , Soja , Aspergillus/metabolismo , COVID-19/terapia , Simulação por Computador , Fungos , Humanos , Metabolômica , SARS-CoV-2
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