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1.
Toxins (Basel) ; 16(2)2024 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-38393188

RESUMO

Common bloom-forming cyanobacteria produce complex strain-specific mixtures of secondary metabolites. The beneficial and toxic properties of these metabolite mixtures have attracted both research and public health interest. The advancement of mass spectrometry-based platforms and metabolomics data processing has accelerated the identification of new metabolites and feature dereplication from microbial sources. The objective of this study was to use metabolomics data processing to decipher the intracellular cyanopeptide diversity of six Planktothrix strains collected from Canadian lakes. Data-dependent acquisition experiments were used to collect a non-targeted high-resolution mass spectrometry dataset. Principal component analysis and factor loadings were used to visualize cyanopeptide variation between strains and identified features contributing to the observed variation. GNPS molecular networking was subsequently used to show the diversity of cyanopeptides produced by the Planktothrix strains. Each strain produced a unique mixture of cyanopeptides, and a total of 225 cyanopeptides were detected. Planktothrix sp. CPCC 735 produced the most (n = 68) cyanopeptides, and P. rubescens CPCC 732 produced the fewest (n = 27). Microcystins and anabaenopeptins were detected from all strains. Cyanopeptolins, microviridins and aeruginosins were detected from five, four and two strains, respectively. Cyanopeptolin (n = 80) and anabaenopeptin (n = 61) diversity was the greatest, whereas microcystins (n = 21) were the least diverse. Interestingly, three of the P. rubescens strains had different cyanopeptide profiles, despite being collected from the same lake at the same time. This study highlights the diversity of cyanopeptides produced by Planktothrix and further hints at the underestimated cyanopeptide diversity from subpopulations of chemotypic cyanobacteria in freshwater lakes.


Assuntos
Cianobactérias , Microcistinas , Microcistinas/metabolismo , Planktothrix , Lagos , Canadá , Cianobactérias/metabolismo
3.
J Chem Ecol ; 49(9-10): 528-536, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37322383

RESUMO

Disease suppressive composts are known, yet little information on the potential role of specific microbial antagonist within are available. Arthrobacter humicola isolate M9-1A has been obtained from a compost prepared from marine residues and peat moss. The bacterium is a non-filamentous actinomycete with antagonistic activity against plant pathogenic fungi and oomycetes sharing its ecological niche in agri-food microecosystems. Our objective was to identify and characterize compounds with antifungal activity produced by A. humicola M9-1A. Arthrobacter humicola culture filtrates were tested for antifungal activity in vitro and in vivo and a bioassay-guided approach was used to identify potential chemical determinants of its observed activity against molds. The filtrates reduced the development of lesions of Alternaria rot on tomatoes and the ethyl acetate extract inhibited growth of Alternaria alternata. A compound, arthropeptide B [cyclo-(L-Leu, L-Phe, L-Ala, L-Tyr)], was purified from the ethyl acetate extract of the bacterium. Arthropeptide B is a new chemical structure reported for the first time and has shown antifungal activity against A. alternata spore germination and mycelial growth.


Assuntos
Antifúngicos , Arthrobacter , Antifúngicos/química , Alternaria , Plantas
4.
Toxins (Basel) ; 15(4)2023 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-37104192

RESUMO

Cyanobacterial blooms that release biologically active metabolites into the environment are increasing in frequency as a result of the degradation of freshwater ecosystems globally. The microcystins are one group of cyanopeptides that are extensively studied and included in water quality risk management frameworks. Common bloom-forming cyanobacteria produce incredibly diverse mixtures of other cyanopeptides; however, data on the abundance, distribution, and biological activities of non-microcystin cyanopeptides are limited. We used non-targeted LC-MS/MS metabolomics to study the cyanopeptide profiles of five Microcystis strains: four M. aeruginosa and one M. flos-aquae. Multivariate analysis and GNPS molecular networking demonstrated that each Microcystis strain produced a unique mixture of cyanopeptides. In total, 82 cyanopeptides from the cyanopeptolin (n = 23), microviridin (n = 18), microginin (n = 12), cyanobactin (n = 14), anabaenopeptin (n = 6), aeruginosin (n = 5), and microcystin (n = 4) classes were detected. Microcystin diversity was low compared with the other detected cyanopeptide classes. Based on surveys of the literature and spectral databases, most cyanopeptides represented new structures. To identify growth conditions yielding high amounts of multiple cyanopeptide groups, we next examined strain-specific cyanopeptide co-production dynamics for four of the studied Microcystis strains. When strains were cultivated in two common Microcystis growth media (BG-11 and MA), the qualitative cyanopeptides profiles remained unchanged throughout the growth cycle. For each of the cyanopeptide groups considered, the highest relative cyanopeptide amounts were observed in the mid-exponential growth phase. The outcomes of this study will guide the cultivation of strains producing common and abundant cyanopeptides contaminating freshwater ecosystems. The synchronous production of each cyanopeptide group by Microcystis highlights the need to make more cyanopeptide reference materials available to investigate their distributions and biological functions.


Assuntos
Cianobactérias , Microcystis , Microcystis/metabolismo , Cromatografia Líquida , Ecossistema , Espectrometria de Massas em Tandem , Microcistinas/análise
5.
J Food Sci ; 87(2): 728-737, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35067916

RESUMO

Coffee silverskin is a byproduct of the coffee roasting process contributing to organic waste burdens in urban areas. Silverskin is a potential source of dietary fiber, protein, carbohydrates, caffeine as well as vitamins and minerals. However, phytosterols present in the plant are susceptible to thermal oxidation resulting in the formation of phytosterol oxidation products (POPs) in the silverskin during roasting. In collaboration with a small roastery, the formation of POPs in three coffee varieties with roasting time was monitored by GC-MS. The objective was to evaluate the safety and potential benefits of incorporating coffee silverskin into value-added products. The qualitative profile of POPs in the silverskin from the three varieties was similar. Average total POPs were 0.32 g POPs/kg silverskin. POPs from the dominant plant sterol, sitosterol, were present at the highest concentrations. Caffeine, total antioxidant capacity, and total flavonoids were measured in the silverskin of the three coffees. Average values were 1.3 g caffeine/100 g silverskin, TEAC of 11 mmol Trolox/kg silverskin, and 1.94 to 8.60 mg catechin equivalent (CE)/g silverskin, respectively. An analysis of the impact of consuming teas and baked goods containing silverskin was also performed. Using published formulations, a tea or cookie containing silverskin would contribute approximately 1 and 0.3 mg POP per day, respectively. Consumption of these products would not substantially increase dietary exposure to POPs, while increasing fiber and antioxidants while reducing organic waste. PRACTICAL APPLICATION: Coffee silverskin has been studied as a possible source of fiber, antioxidants, and caffeine when incorporated in snack foods and used to make teas. To assess possible concerns about increasing dietary oxidized phytosterols, the formation of phytosterol oxidation products (POPs) was investigated in the silverskin fraction during the roasting process in three coffee varieties. In addition, caffeine, antioxidant capacity, and total flavonoids were determined. We found that silverskin can be safely used for value-added products including caffeinated teas, cookies, and bars with minimal impact on dietary POP exposures.


Assuntos
Coffea , Fitosteróis , Antioxidantes , Coffea/química , Café , Oxirredução , Fitosteróis/química , Extratos Vegetais
6.
Nat Prod Res ; 36(22): 5715-5723, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34933636

RESUMO

In an effort to describe bioactive antifungal compounds from antagonistic bacteria with potential for biocontrol of plant pathogens, a strain of Arthrobacter psychrophenolicus was collected from plant disease suppressive compost prepared from composted material of marine origin. Few natural products have been characterized from the non-filamentous Actinobacteria genus Arthrobacter. A new cyclic tetrapeptide, cyclo-(L-Pro-L-Leu-L-γHyp-L-Tyr); arthropeptide A (1), was isolated from the EtOAc soluble culture filtrate extract of A. psychrophenolicus M9-17 grown in MOLP broth. Its structure was confirmed by HRMS, interpretation of NMR data, and a modified Marfey's method. Arthropeptide A (1) displayed antifungal activity towards Alternaria alternata, the causal agent of disease in numerous host plant species, which had shown the previous susceptibility to A. psychrophenolicus. The newly identified compound may be responsible, in part, for the inhibitory activity of the bacterium against fungal plant pathogens.


Assuntos
Compostagem , Micrococcaceae , Antifúngicos/química , Testes de Sensibilidade Microbiana , Bactérias , Peptídeos Cíclicos
7.
Clin Ophthalmol ; 15: 3889-3900, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34588761

RESUMO

PURPOSE: To assess the subjective eye drop experience of patients with dry eye disease (DED) over approximately 1 hour after a single dose of two formulations of reproxalap versus lifitegrast. METHODS: Two formulations of topical ocular reproxalap 0.25% were evaluated versus lifitegrast ophthalmic solution 5% in patients with DED in a single-center, double-masked, active-comparator, single-dose crossover clinical trial. Nineteen patients had test article topically administered to both eyes. Treatments were administered 2 to 4 days apart. Comfort assessments, including ocular discomfort, blurry vision, and dysgeusia assessments; ocular descriptive assessments; quality of life assessments; and overall experience questions were completed after each treatment over one hour, beginning at 90 seconds. RESULTS: Both reproxalap formulations scored better in ocular discomfort score (ODS), blurry vision, and dysgeusia assessments than lifitegrast at each timepoint and cumulatively over all time points after instillation. There were lower rates of negative responses for both reproxalap formulations compared to lifitegrast across ocular discomfort, blurry vision, and dysgeusia assessments, and the durations of negative responses were shorter with reproxalap than with lifitegrast. The reproxalap groups experienced fewer quality of life impacts. No significant safety findings were observed following reproxalap or lifitegrast administration. CONCLUSION: The reproxalap eye drop experience over 1 hour after instillation was superior to that of lifitegrast. There were no statistically significant differences between reproxalap groups for ODS, blurry vision, or dysgeusia. The improved performance of reproxalap with regard to the most commonly reported side effects of lifitegrast (ie, ocular discomfort, blurry vision, and dysgeusia) may result in greater patient adherence and lower discontinuation rates.

8.
J Basic Microbiol ; 61(8): 745-756, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34228381

RESUMO

Antagonistic bacteria can act as biocontrol agents against various phytopathogens. Recently, Arthrobacter spp. demonstrated antifungal activity, but were not further characterized. In this study, the antimicrobial activity of Arthrobacter humicola strains M9-1A, M9-2, and M9-8, and Arthrobacter psychrophenolicus strain M9-17 were evaluated against nine plant pathogens in vitro, and their cell-free filtrates were additionally assessed for inhibition of Alternaria alternata and suppression of black mold disease on tomato fruit. Results indicated that A. humicola M9-1A and A. psychrophenolicus M9-17 were the most inhibitory, reducing growth of seven of the pathogens studied. Cell-free filtrates of A. psychrophenolicus M9-17 reduced the growth of most pathogens. All cell-free bacterial filtrates, except those from A. humicola M9-2, suppressed black mold on tomato fruit. Disk diffusion assays with ethyl acetate soluble culture filtrate extracts of all bacteria reduced the mycelial growth of A. alternata. Clear inhibition zones were observed for A. psychrophenolicus M9-17 extracts using drop bioassays. The antifungal compound N-acetyltryptamine was purified and characterized from the A. psychrophenolicus M9-17 cell-free ethyl acetate soluble extract. This study suggests that antibiosis may play a key role in the antimicrobial activity of Arthrobacter spp.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Arthrobacter/isolamento & purificação , Arthrobacter/metabolismo , Compostagem , Alternaria/efeitos dos fármacos , Antibiose/efeitos dos fármacos , Antifúngicos/química , Antifúngicos/farmacologia , Frutas/microbiologia , Solanum lycopersicum/microbiologia , Micrococcaceae , Doenças das Plantas/microbiologia
9.
Neurology ; 97(2): e203-e214, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-33986139

RESUMO

OBJECTIVE: To determine the influence of patent foramen ovale (PFO) closure on circulatory biomarkers. METHODS: Consecutive patients with PFO-related stroke were prospectively enrolled and followed with serial sampling of cardiac atrial and venous blood pre- and post-PFO closure over time. Candidate biomarkers were identified by mass spectrometry in a discovery cohort first, and lead candidates were validated in an independent cohort. RESULTS: Patients with PFO-related stroke (n = 254) were recruited and followed up to 4 years (median 2.01; interquartile range 0.77-2.54). Metabolite profiling in the discovery cohort (n = 12) identified homocysteine as the most significantly decreased factor in intracardiac plasma after PFO closure (false discovery rate 0.001). This was confirmed in a validation cohort (n = 181), where intracardiac total homocysteine (tHcy) was immediately reduced in patients with complete closure, but not in those with residual shunting, suggesting association of PFO shunting with tHcy elevation (ß 0.115; 95% confidence interval [CI] 0.047-0.183; p = 0.001). tHcy reduction was more dramatic in left atrium than right (p < 0.001), suggesting clearance through pulmonary circulation. Long-term effect of PFO closure was also monitored and compared to medical treatment alone (n = 61). Complete PFO closure resulted in long-term tHcy reduction in peripheral blood, whereas medical therapy alone showed no effect (ß -0.208; 95% CI -0.375∼-0.058; p = 0.007). Residual shunting was again independently associated with persistently elevated tHcy (ß 0.184; 95% CI 0.051-0.316; p = 0.007). CONCLUSIONS: PFO shunting may contribute to circulatory tHcy elevation, which is renormalized by PFO closure. PFO is not just a door for clots, but may itself enhance clot formation and injure neurovasculature by clot-independent mechanisms. Biomarkers such as tHcy can potentially serve as cost-effective measures of residual shunting and neurovascular risk for PFO stroke.


Assuntos
Forame Oval Patente/sangue , Forame Oval Patente/complicações , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/complicações , Adulto , Biomarcadores/sangue , Feminino , Homocisteína/sangue , Humanos , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Estudos Prospectivos
10.
Environ Toxicol Chem ; 40(4): 1087-1097, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33238037

RESUMO

Cyanobacteria are ubiquitous photosynthetic prokaryotes that produce structurally diverse bioactive metabolites. Although microcystins are extensively studied, other cyanopeptides produced by common bloom-forming species have received little attention. Cyanopeptolins are a large cyanopeptide group that contain a characteristic 3-amino-6-hydroxy-2-piperidone (Ahp) moiety. In the present study we used diagnostic fragmentation filtering (DFF), a semitargeted liquid chromatography-tandem mass spectrometry (MS/MS) product ion filtering approach, to investigate cyanopeptolin diversity from 5 Microcystis strains and 4 bloom samples collected from lakes in Ontario and Quebec, Canada. Data processing by DFF was used to search MS/MS data sets for pairs of diagnostic product ions corresponding to cyanopeptolin partial sequences. For example, diagnostic product ions at m/z 150.0912 and 215.1183 identified cyanopeptolins with the NMe-Tyr-Phe-Ahp partial sequence. Forty-eight different cyanopeptolins, including 35 new variants, were detected from studied strains and bloom samples. Different cyanopeptolin profiles were identified from each sample. We detected a new compound, cyanopeptolin 1143, from a bloom and elucidated its planar structure from subsequent targeted MS/MS experiments. Diagnostic fragmentation filtering is a rapid, easy-to-perform postacquisition metabolomics strategy for inferring structural features and prioritizing new compounds for further study and dereplication. More work on cyanopeptolin occurrence and toxicity is needed because their concentrations in freshwater lakes after blooms can be similar to those of microcystins. Environ Toxicol Chem 2021;40:1087-1097. © 2020 SETAC.


Assuntos
Cianobactérias , Depsipeptídeos , Microcistinas , Lagos , Ontário , Espectrometria de Massas em Tandem
11.
JACC Cardiovasc Interv ; 13(23): 2745-2752, 2020 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-33303111

RESUMO

OBJECTIVES: The aim of this study was to investigate the effect of management on the risk for recurrent events among patients with cryptogenic ischemic stroke or transient ischemic attack. BACKGROUND: The combination of patent foramen ovale (PFO) and hypercoagulability may greatly increase the risk for paradoxical embolism. However, previous randomized controlled trials evaluating the efficacy of PFO closure excluded these potential high-risk patients. METHODS: Patients diagnosed with PFO attributable cryptogenic embolism were prospectively, without randomization, recruited from January 2005 to March 2018. The relationship between thrombophilia and recurrent events was evaluated in overall patients. Multivariate Cox regression was conducted to assess the relative risk for recurrence in PFO closure and medical therapy groups. RESULTS: A total of 591 patients with cryptogenic embolism with PFO were identified. The median duration of follow-up was 53 months, and thrombophilia significantly increased the risk for recurrent events (hazard ratio [HR]: 1.85; 95% confidence interval [CI]: 1.09 to 3.16; p = 0.024). PFO closure was superior to medical therapy in overall patients (HR: 0.16; 95% CI: 0.09 to 0.30; p < 0.001). Of the 134 patients (22.7%) with thrombophilia, there was a difference in the risk for recurrence events between the PFO closure (6 of 89) and medical therapy (15 of 45) groups (HR: 0.25; 95% CI: 0.08 to 0.74; p = 0.012). There was no potential heterogeneity in the further subgroup analysis. CONCLUSIONS: Patients with cryptogenic stroke with PFO and hypercoagulable state had increased risk for recurrent stroke or transient ischemic attack. PFO closure provided a lower risk for recurrent events compared with medical therapy alone.


Assuntos
Embolia , Forame Oval Patente , Trombofilia , Humanos , Ataque Isquêmico Transitório , Recidiva , Prevenção Secundária , Dispositivo para Oclusão Septal , Acidente Vascular Cerebral , Resultado do Tratamento
13.
Ann Intern Med ; 172(11): 717-725, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32422058

RESUMO

BACKGROUND: Residual shunt is observed in up to 25% of patients after patent foramen ovale (PFO) closure, but its long-term influence on stroke recurrence currently is unknown. OBJECTIVE: To investigate the association of residual shunt after PFO closure with the incidence of recurrent stroke and transient ischemic attack (TIA). DESIGN: Prospective cohort study comparing stroke or TIA recurrence in patients with and without residual shunt after PFO closure. SETTING: Single hospital center. PARTICIPANTS: 1078 consecutive patients (mean age, 49.3 years) with PFO-attributable cryptogenic stroke who were undergoing percutaneous PFO closure were followed for up to 11 years. MEASUREMENTS: Residual shunt was evaluated by transthoracic echocardiography with saline contrast. Primary outcome was a composite of the first recurrent ischemic stroke or TIA after PFO closure. RESULTS: Compared with complete closure, the presence of residual shunt after PFO closure was associated with an increased incidence of recurrent stroke or TIA: 2.32 versus 0.75 events per 100 patient-years (hazard ratio [HR], 3.05 [95% CI, 1.65 to 5.62]; P < 0.001). This result remained robust after adjustment for important covariates, namely age; study period; device; presence of atrial septal aneurysm, hypertension, hyperlipidemia, diabetes, hypercoagulability, or hypermobile septum; and medication use (HR, 3.01 [CI, 1.59 to 5.69]; P < 0.001). Further stratification based on shunt size revealed that moderate or large residual shunts were associated with a higher risk for stroke or TIA recurrence (HR, 4.50 [CI, 2.20 to 9.20]; P < 0.001); the result for small residual shunts was indeterminate (HR, 2.02 [CI, 0.87 to 4.69]; P = 0.102). LIMITATION: Nonrandomized study with potential unmeasured confounding. CONCLUSION: Among patients undergoing PFO closure to prevent future stroke, the presence of residual shunt, particularly a moderate or large residual shunt, was associated with an increased risk for stroke or TIA recurrence. PRIMARY FUNDING SOURCE: National Institutes of Health.


Assuntos
Forame Oval Patente/complicações , Acidente Vascular Cerebral/etiologia , Ecocardiografia , Feminino , Forame Oval Patente/diagnóstico por imagem , Forame Oval Patente/cirurgia , Humanos , Ataque Isquêmico Transitório/epidemiologia , Ataque Isquêmico Transitório/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Recidiva , Acidente Vascular Cerebral/epidemiologia
14.
J Vis Exp ; (147)2019 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-31205310

RESUMO

Natural products are often biosynthesized as mixtures of structurally similar compounds, rather than a single compound. Due to their common structural features, many compounds within the same class undergo similar MS/MS fragmentation and have several identical product ions and/or neutral losses. The purpose of diagnostic fragmentation filtering (DFF) is to efficiently detect all compounds of a given class in a complex extract by screening non-targeted LC-MS/MS datasets for MS/MS spectra that contain class specific product ions and/or neutral losses. This method is based on a DFF module implemented within the open-source MZmine platform that requires sample extracts be analyzed by data-dependent acquisition on a high-resolution mass spectrometer such as quadrupole Orbitrap or quadrupole time-of-flight mass analyzers. The main limitation of this approach is the analyst must first define which product ions and/or neutral losses are specific for the targeted class of natural products. DFF allows for the subsequent discovery of all related natural products within a complex sample, including new compounds. In this work, we demonstrate the effectiveness of DFF by screening extracts of Microcystis aeruginosa, a prominent harmful algal bloom causing cyanobacteria, for the production of microcystins.


Assuntos
Produtos Biológicos/análise , Cromatografia Líquida/métodos , Descoberta de Drogas , Microcistinas/análise , Espectrometria de Massas em Tandem/métodos , Cianobactérias/química , Íons , Microcistinas/química , Microcystis/química
15.
Rapid Commun Mass Spectrom ; 33(1): 133-139, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30325552

RESUMO

RATIONALE: Microbial natural products are often biosynthesized as classes of structurally related compounds that have similar tandem mass spectrometry (MS/MS) fragmentation patterns. Mining MS/MS datasets for precursor ions that share diagnostic or common features enables entire chemical classes to be identified, including novel derivatives that have previously been unreported. Analytical data analysis tools that can facilitate a class-targeted approach to rapidly dereplicate known compounds and identify structural variants within complex matrices would be useful for the discovery of new natural products. METHODS: A diagnostic fragmentation filtering (DFF) module was developed for MZmine to enable the efficient screening of MS/MS datasets for class-specific product ions(s) and/or neutral loss(es). This approach was applied to series of the structurally related chaetoglobosin and cytochalasin classes of compounds. These were identified from the culture filtrates of three fungal genera: Chaetomium globosum, a putative new species of Penicillium (called here P. cf. discolor: closely related to P. discolor), and Xylaria sp. Extracts were subjected to LC/MS/MS analysis under positive electrospray ionization and operating in a data-dependent acquisition mode, performed using a Thermo Q-Exactive mass spectrometer. All MS/MS datasets were processed using the DFF module and screened for diagnostic product ions at m/z 130.0648 and 185.0704 for chaetoglobosins, and m/z 120.0808 and 146.0598 for cytochalasins. RESULTS: Extracts of C. globosum and P. cf. discolor strains revealed different mixtures of chaetoglobosins, whereas the Xylaria sp. produced only cytochalasins; none of the strains studied produced both classes of compounds. The dominant chaetoglobosins produced by both C. globosum and P. cf. discolor were chaetoglobosins A, C, and F. Tetrahydrochaetoglobosin A was identified from P. cf. discolor extracts and is reported here for the first time as a natural product. The major cytochalasins produced by the Xylaria sp. were cytochalasin D and epoxy cytochalasin D. A larger unknown "cytochalasin-like" molecule with the molecular formula C38 H47 NO10 was detected from Xylaria sp. culture filtrate extracts and is a current target for isolation and structural characterization. CONCLUSIONS: DFF is an effective LC/MS data analysis approach for rapidly identifying entire classes of compounds from complex mixtures. DFF has proved useful in the identification of new natural products and allowing for their partial characterization without the need for isolation.


Assuntos
Citocalasinas/química , Descoberta de Drogas/métodos , Alcaloides Indólicos/química , Software , Espectrometria de Massas em Tandem/métodos , Chaetomium/química , Chaetomium/metabolismo , Cromatografia Líquida , Citocalasinas/análise , Avaliação Pré-Clínica de Medicamentos/métodos , Fermentação , Alcaloides Indólicos/análise , Metabolômica/métodos , Penicillium/química , Penicillium/metabolismo , Xylariales/química , Xylariales/metabolismo
16.
PLoS One ; 13(6): e0198321, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29949590

RESUMO

Surveys of foliar endophytes from the Acadian forest region over the past three decades have identified numerous phylogenetically diverse fungi producing natural products toxic to forest pests and diseases. The life histories of some conifer endophytes can be restricted to plant foliage or may include saprotrophic phases on other plants tissues or even alternate hosts. Considering the potentially broad host preferences of conifer endophytes we explored fungi isolated from understory species and their metabolites as part of an ongoing investigation of fungal biodiversity from the Acadian forest. We report a hitherto unidentified Xylariomycetidae species isolated from symptomatic Labrador tea (Rhododendron groenlandicum) leaves and mountain laurel (Kalmia latifolia) collected in coastal southern New Brunswick, Canada. Morphological and phylogenetic evidence demonstrated the unknown species was a novel Synnemapestaloides (Sporocadaceae) species, described here as Syn. ericacearum. A preliminary screening assay indicated that the culture filtrate extract of the new species was potently antifungal towards the biotrophic pathogen Microbotryum violaceum, warranting an investigation of its natural products. Two natural products possessing a rare 1,3-benzodioxin-4-one scaffold, synnemadoxins A-B (1-2), and their postulated precursor, synnemadiacid A (3), were characterized as new structures and assessed for antimicrobial activity. All isolated compounds elicited in vitro inhibitory antifungal activity towards M. violaceum at 2.3 µg mL-1 and moderate antibiotic activity. Further, the characterization of synnemadoxins A-B provided a perspective on the biosynthesis of some related 1,3-benzodioxin-4-ones produced by other fungi within the Xylariales.


Assuntos
Dioxóis/isolamento & purificação , Ericaceae/microbiologia , Ledum/microbiologia , Xylariales/química , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Dioxóis/química , Dioxóis/farmacologia , Estrutura Molecular , Novo Brunswick , Filogenia , Folhas de Planta/microbiologia , Xylariales/classificação , Xylariales/isolamento & purificação
17.
Transl Stroke Res ; 9(1): 64-73, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28812241

RESUMO

Therapeutic hypothermia (TH) is a neuroprotective treatment post-cardiac arrest but is grossly underutilized. After TH induction, traditional biomarkers and parameters can no long predict clinical outcome due to a lack of understanding of hypothermic response. Innovative approaches to better understand the clinical effect of TH will help to prognosticate outcome and expand beneficial population. Protein glycosylation is an important extracellular post-translational modification, regulating various extracellular signaling pathways. Here, we used glycoproteomics to investigate the association of plasma glycoproteins with the prognosis of TH-treated cardiac arrest patients. Using lectin affinity chromatography and mass spectrometry, we identified 640 glycoproteins in the plasma of cardiac arrest patients undergoing TH treatment, of which 23 were up-regulated and 14 were down-regulated in good outcome patients as compared with poor outcome ones. Notably, two glycoproteins with antioxidant activity, ceruloplasmin (CP) and haptoglobin (HP), were found to be associated with favorable neurologic outcome. This was further supported by ELISA assay in a large patients cohort, in which glycosylated CP and HP enriched by concanavilin A (ConA) and wheat germ agglutinin (WGA) lectins were significantly increased in patients developing good outcome (ConA-CP: p = 0.033; ConA-HP: p = 0.04; WGA-HP: p = 0.021). Furthermore, ROC analysis demonstrated the predictive potential of ConA-CP, ConA-HP, and WGA-HP (ConA-CP: AUC = 0.732, p = 0.031; ConA-HP: AUC = 0.746, p = 0.022; WGA-HP: AUC = 0.714, p = 0.046) and combination of them improved the predictive power (AUC = 0.830, p = 0.002). Our results suggested that glycosylated CP and HP as well as other glycoproteins may play critical roles in neuroprotection and serve as sensitive prognostic markers for TH treatments.


Assuntos
Glicoproteínas/sangue , Parada Cardíaca , Hipotermia Induzida/métodos , Doenças do Sistema Nervoso , Resultado do Tratamento , Adulto , Idoso , Ceruloplasmina/metabolismo , Feminino , Haptoglobinas/metabolismo , Parada Cardíaca/sangue , Parada Cardíaca/complicações , Parada Cardíaca/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/sangue , Doenças do Sistema Nervoso/etiologia , Doenças do Sistema Nervoso/terapia , Exame Neurológico , Avaliação de Resultados em Cuidados de Saúde , Proteômica , Curva ROC
18.
J Chromatogr A ; 1508: 65-72, 2017 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-28619584

RESUMO

Several moderately pathogenic Fusarium species produce enniatins, a family of cyclohexadepsipeptides with insecticidal and phytotoxic activities. A semi-targeted LC-MS/MS approach utilizing reversed-phase C8 UHPLC column chromatography that combines both product ion and neutral loss filtering was developed to detect enniatins and structurally-related compounds in a sample. Using this methodology, resolution of all major enniatins was achieved with a 6-min LC run. From extracts of F. avenaceum, F. acuminatum and F. subglutinans, 23 enniatins and 16 previously unreported bassianolide-like cyclooctadepsipeptides were detected. Enniatins B, B1, A1 and A were the most frequently detected enniatins from silage and inoculated maize. The newly discovered bassianolide compounds were also detected, in lesser amounts on inoculated maize and in naturally contaminated silage.


Assuntos
Cromatografia Líquida/métodos , Depsipeptídeos/química , Fusarium/química , Peptídeos Cíclicos/química , Espectrometria de Massas em Tandem/métodos , Depsipeptídeos/metabolismo , Fusarium/metabolismo , Espectrometria de Massas , Peptídeos Cíclicos/metabolismo , Zea mays/química , Zea mays/microbiologia
19.
Toxicol In Vitro ; 43: 16-20, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28535995

RESUMO

Most fungi that grow on damp building materials produce low molecular weight compounds, some of which are known to be toxic. In this study, we tested the hypothesis that exposure to some metabolites of fungi common on damp building materials would result in time-, dose-, and compound-specific responses in the production of various chemokines by RAW 264.7 cells. Cell cultures were exposed to a 10-7M or 10-8M metabolite dose for 2, 4, 8 or 24h. Metabolite concentrations used were based on those that might be expected in alveolar macrophages due to inhalation exposure from living or working in a damp building. Compared to controls, exposure provoked significant time-, dose- and compound-specific responses manifest as differentially elevated secretion of three of nine cytokines tested in culture supernatant of treated cells. The greatest number of cytokines produced in response to the metabolites tested were in andrastin A-treated cells (GM-CSF, TGFß1, Tnf-α) followed by koninginin A (TGFß1 and Tnf-α) and phomenone (GM-CSF, TGFß1). Chaetoglobosin A, chaetomugilin D and walleminone exposures each resulted in significant time-specific production of Tnf-α only. This investigation adds to a body of evidence supporting the role of low molecular weight compounds from damp building materials as pathogen associated molecular patterns (PAMPs). Along with fungal glucan and chitin, these compounds contribute to the non-allergy based respiratory outcomes for people living and working in damp buildings.


Assuntos
Materiais de Construção/microbiologia , Citocinas/metabolismo , Macrófagos/efeitos dos fármacos , Micotoxinas/toxicidade , Animais , Fungos/metabolismo , Inflamação/genética , Inflamação/metabolismo , Macrófagos/metabolismo , Camundongos , Células RAW 264.7 , Transcrição Gênica/efeitos dos fármacos
20.
Can J Microbiol ; 63(7): 621-632, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28384416

RESUMO

Buildings that have been flooded often have high concentrations of Trichoderma spores in the air while drying. Inhaled spores and spore and mycelial fragments contain large amounts of fungal glucan and natural products that contribute to the symptoms associated with indoor mould exposures. In this study, we considered both small molecules and peptaibol profiles of T. atroviride, T. koningiopsis, T. citrinoviride, and T. harzianum strains obtained from damp buildings in eastern Canada. Twenty-residue peptaibols and sorbicillin-derived metabolites (1-6) including a new structure, (R)-vertinolide (1), were characterized from T. citrinoviride. Trichoderma koningiopsis produced several koninginins (7-10), trikoningin KA V, and the 11-residue lipopeptaibols trikoningin KB I and trikoningin KB II. Trichoderma atroviride biosynthesized a mixture of 19-residue trichorzianine-like peptaibols, whereas T. harzianum produced 18-residue trichokindin-like peptaibols and the 11-residue harzianin HB I that was subsequently identified from the studied T. citrinoviride strain. Two α-pyrones, 6-pentyl-pyran-2-one (11) and an oxidized analog (12), were produced by both T. atroviride and T. harzianum. Aside from exposure to low molecular weight natural products, inhalation of Trichoderma spores and mycelial fragments may result in exposure to membrane-disrupting peptaibols. This investigation contributes to a more comprehensive understanding of the biologically active natural products produced by fungi commonly found in damp buildings.


Assuntos
Peptaibols/metabolismo , Trichoderma/metabolismo , Sequência de Aminoácidos , Materiais de Construção/microbiologia , Microbiologia Ambiental , Nova Escócia , Ontário , Peptaibols/química , Peptaibols/isolamento & purificação , Quebeque , Trichoderma/química , Trichoderma/isolamento & purificação
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