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1.
Int J Biol Macromol ; 264(Pt 1): 130458, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38423421

RESUMO

The PD-1/PD-L1 protein-protein interaction (PPI) controls an adaptive immune resistance mechanism exerted by tumor cells to evade immune responses. The large-molecule nature of current commercial monoclonal antibodies against this PPI hampers their effectiveness by limiting tumor penetration and inducing severe immune-related side effects. Synthetic small-molecule inhibitors may overcome such limitations and have demonstrated promising clinical translation, but their design is challenging. Microbial natural products (NPs) are a source of small molecules with vast chemical diversity that have proved anti-tumoral activities, but which immunotherapeutic properties as PD-1/PD-L1 inhibitors had remained uncharacterized so far. Here, we have developed the first cell-based PD-1/PD-L1 blockade reporter assay to screen NPs libraries. In this study, 6000 microbial extracts of maximum biosynthetic diversity were screened. A secondary metabolite called alpha-cyclopiazonic acid (α-CPA) of a bioactive fungal extract was confirmed as a new PD-1/PD-L1 inhibitor with low micromolar range in the cellular assay and in an additional cell-free competitive assay. Thermal denaturation experiments with PD-1 confirmed that the mechanism of inhibition is based on its stabilization upon binding to α-CPA. The identification of α-CPA as a novel PD-1 stabilizer proves the unprecedented resolution of this methodology at capturing specific PD-1/PD-L1 PPI inhibitors from chemically diverse NP libraries.


Assuntos
Antígeno B7-H1 , Neoplasias , Humanos , Antígeno B7-H1/metabolismo , Receptor de Morte Celular Programada 1/metabolismo , Anticorpos Monoclonais
2.
Molecules ; 29(2)2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38257340

RESUMO

Cancer is one of the leading causes of death worldwide, with breast cancer being the second cause of cancer-related mortality among women. Natural Products (NPs) are one of the main sources for drug discovery. During a screening campaign focused on the identification of extracts from Fundación MEDINA's library inhibiting the proliferation of cancer cell lines, a significant bioactivity was observed in extracts from cultures of the fungus Angustimassarina populi CF-097565. Bioassay-guided fractionation of this extract led to the identification and isolation of herbarin (1), 1-hydroxydehydroherbarin (4) plus other three naphthoquinone derivatives of which 3 and 5 are new natural products and 2 is herein described from a natural source for the first time. Four of these compounds (1, 3, 4 and 5) confirmed a specific cytotoxic effect against the human breast cancer cell line MCF-7. To evaluate the therapeutic potential of the compounds isolated, their efficacy was validated in 3D cultures, a cancer model of higher functionality. Additionally, an in-depth study was carried out to test the effect of the compounds in terms of cell mortality, sphere disaggregation, shrinkage, and morphology. The cell profile of the compounds was also compared to that of known cytotoxic compounds with the aim to distinguish the drug mode of action (MoA). The profiles of 1, 3 and 4 showed more biosimilarity between them, different to 5, and even more different to other known cytotoxic agents, suggesting an alternative MoA responsible for their cytotoxicity in 3D cultures.


Assuntos
Ascomicetos , Medicamentos Biossimilares , Neoplasias da Mama , Feminino , Humanos , Neoplasias da Mama/tratamento farmacológico , Bioensaio
3.
Biomed Pharmacother ; 170: 116056, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38159372

RESUMO

Duchenne muscular dystrophy (DMD) is a devastating degenerative disease of skeletal muscles caused by loss of dystrophin, a key protein that maintains muscle integrity, which leads to progressive muscle degeneration aggravated by chronic inflammation, muscle stem cells' (MuSCs) reduced regenerative capacity and replacement of muscle with fibroadipose tissue. Previous research has shown that pharmacological GSK-3ß inhibition favors myogenic differentiation and plays an important role in modulating inflammatory processes. Isolecanoric acid (ILA) is a natural product isolated from a fungal culture displaying GSK-3ß inhibitory properties. The present study aimed to investigate the proregenerative and anti-inflammatory properties of this natural compound in the DMD context. Our results showed that ILA markedly promotes myogenic differentiation of myoblasts by increasing ß-Catenin signaling and boosting the myogenic potential of mouse and human stem cells. One important finding was that the GSK-3ß/ß-Catenin pathway is altered in dystrophic mice muscle and ILA enhances the myofiber formation of dystrophic MuSCs. Treatment with this natural compound improves muscle regeneration of dystrophic mice by, in turn, improving functional performance. Moreover, ILA ameliorates the inflammatory response in both muscle explants and the macrophages isolated from dystrophic mice to, thus, mitigate fibrosis after muscle damage. Overall, we show that ILA modulates both inflammation and muscle regeneration to, thus, contribute to improve the dystrophic phenotype.


Assuntos
Distrofia Muscular de Duchenne , Animais , Camundongos , Humanos , Distrofia Muscular de Duchenne/tratamento farmacológico , Distrofia Muscular de Duchenne/metabolismo , beta Catenina/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Camundongos Endogâmicos mdx , Músculo Esquelético , Inflamação/metabolismo , Modelos Animais de Doenças
4.
J Fungi (Basel) ; 9(9)2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37754991

RESUMO

Fungal phytopathogens are the major agents responsible for causing severe damage to and losses in agricultural crops worldwide. Botrytis cinerea, Colletotrichum acutatum, Fusarium proliferatum, and Magnaporthe grisea are included in the top ten fungal phytopathogens that impose important plant diseases on a broad range of crops. Microbial natural products can be an attractive alternative for the biological control of phytopathogens. The objective of this work was to develop and validate a High-throughput Screening (HTS) platform to evaluate the antifungal potential of chemicals and natural products against these four important plant pathogens. Several experiments were performed to establish the optimal assay conditions that provide the best reproducibility and robustness. For this purpose, we have evaluated two media formulations (SDB and RPMI-1640), several inoculum concentrations (1 × 106, 5 × 105 and 5 × 106 conidia/mL), the germination curves for each strain, each strain's tolerance to dimethyl sulfoxide (DMSO), and the Dose Response Curves (DRC) of the antifungal control (Amphotericin B). The assays were performed in 96-well plate format, where absorbance at 620 nm was measured before and after incubation to evaluate growth inhibition, and fluorescence intensity at 570 nm excitation and 615 nm emission was monitored after resazurin addition for cell viability evaluation. Quality control parameters (RZ' Factors and Signal to Background (S/B) ratios) were determined for each assay batch. The assay conditions were finally validated by titrating 40 known relevant antifungal agents and testing 2400 microbial natural product extracts from the MEDINA Library through both HTS agar-based and HTS microdilution-based set-ups on the four phytopathogens.

5.
J Fungi (Basel) ; 9(9)2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37754995

RESUMO

In a survey to evaluate the potential of lichens associated with gypsum areas as sources of new antifungal metabolites, six species of lichens were collected in the gypsum outcrops of the Sorbas Desert (Diploschistes ocellatus and Seirophora lacunosa) and the Tabernas Desert (Cladonia foliacea, Acarospora placodiformis, Squamarina lentigera and Xanthoparmelia pokornyi) in southern Spain. Raw lichen acetone extracts were tested against a panel of seven phytopathogenic fungi, including Botrytis cinerea, Colletotrichum acutatum, Fusarium oxysporum f.sp cubense TR4, Fusarium ploriferaum, Magnaporthe grisea, Verticillium dahliae and Zymoseptoria tritici. Active extracts of Cladonia foliacea, Xanthoparmelia pokornyi and Squamarina lentigera were analyzed by HPLC-MS/MS and Molecular Networking to identify possible metabolites responsible for the antifungal activity. A total of ten depside-like metabolites were identified by MS/MS dereplication and NMR experiments, of which one was a new derivative of fumaroprotocetraric acid. The compounds without previously described biological activity were purified and tested against the panel of fungal phytopathogens. Herein, the antifungal activity against fungal phytopathogens of 4'-O-methylpaludosic acid, divaricatic acid and stenosporic acid is reported for the first time. Stenosporic and divaricatic acids displayed a broad antifungal spectrum against seven relevant fungal phytopathogens in a micromolar range, including the extremely resistant fungus F. oxysporum f. sp. cubense Tropical Race 4 (TR4). 4'-O-methylpaludosic acid exhibited specific antifungal activity against the wheat pathogen Z. tritici, with an IC50 of 38.87 µg/mL (87.1 µM) in the absorbance-based assay and 24.88 µg/mL (55.52 µM) in the fluorescence-based assay.

6.
Pharmaceutics ; 15(2)2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36839814

RESUMO

Memnoniella is a fungal genus from which a wide range of diverse biologically active compounds have been isolated. A Memnoniella dichroa CF-080171 extract was identified to exhibit potent activity against Plasmodium falciparum 3D7 and Trypanosoma cruzi Tulahuen whole parasites in a high-throughput screening (HTS) campaign of microbial extracts from the Fundación MEDINA's collection. Bioassay-guided isolation of the active metabolites from this extract afforded eight new meroterpenoids of varying potencies, namely, memnobotrins C-E (1-3), a glycosylated isobenzofuranone (4), a tricyclic isobenzofuranone (5), a tetracyclic benzopyrane (6), a tetracyclic isobenzofuranone (7), and a pentacyclic isobenzofuranone (8). The structures of the isolated compounds were established by (+)-ESI-TOF high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy. Compounds 1, 2, and 4 exhibited potent antiparasitic activity against P. falciparum 3D7 (EC50 0.04-0.243 µM) and T. cruzi Tulahuen (EC50 0.266-1.37 µM) parasites, as well as cytotoxic activity against HepG2 tumoral liver cells (EC50 1.20-4.84 µM). The remaining compounds (3, 5-8) showed moderate or no activity against the above-mentioned parasites and cells.

7.
Int J Mol Sci ; 23(11)2022 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-35682786

RESUMO

Sleeping sickness or African trypanosomiasis is a serious health concern with an added socio-economic impact in sub-Saharan Africa due to direct infection in both humans and their domestic livestock. There is no vaccine available against African trypanosomes and its treatment relies only on chemotherapy. Although the current drugs are effective, most of them are far from the modern concept of a drug in terms of toxicity, specificity and therapeutic regime. In a search for new molecules with trypanocidal activity, a high throughput screening of 2000 microbial extracts was performed. Fractionation of one of these extracts, belonging to a culture of the fungus Amesia sp., yielded a new member of the curvicollide family that has been designated as curvicollide D. The new compound showed an inhibitory concentration 50 (IC50) 16-fold lower in Trypanosoma brucei than in human cells. Moreover, it induced cell cycle arrest and disruption of the nucleolar structure. Finally, we showed that curvicollide D binds to DNA and inhibits transcription in African trypanosomes, resulting in cell death. These results constitute the first report on the activity and mode of action of a member of the curvicollide family in T. brucei.


Assuntos
Tripanossomicidas , Trypanosoma brucei brucei , Tripanossomíase Africana , Animais , Fungos , Humanos , Tripanossomicidas/química , Tripanossomicidas/farmacologia , Tripanossomíase Africana/tratamento farmacológico
8.
Sci Rep ; 12(1): 1649, 2022 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-35102193

RESUMO

As part of our screening program for the discovery of molecules of microbial origin with skin-whitening activity, 142 diverse fungal endophytes from a wide variety of Andalusia arid plants were screened, applying the OSMAC approach. The fungal strains CF-090361 and CF-090766, isolated from xerophytic plants, were selected as the most promising, while phylogenetic analysis revealed that both strains could represent a new species within the genus Comoclathris. The effect of different fermentation conditions on the production of tyrosinase inhibitory activity was examined, in order to identify the optimum cultivation conditions. LCMS based metabolomics was applied to determine significant differences between the strains and fermentation conditions, and to identify potential bioactive secondary metabolites. Bioassay-guided purification of the main active components led to the isolation of three new compounds (1-3), along with the known compounds graphostrin B (4) and brevianamide M (5). Compound 1 (Comoclathrin) demonstrated the strongest anti-tyrosinase activity (IC50 0.16 µΜ), which was 90-times higher than kojic acid (IC50 14.07 µΜ) used as positive control. Additionally, comoclathrin showed no significant cytotoxicity against a panel of cancer cell lines (HepG2, A2058, A549, MCF-7 and MIA PaCa-2) and normal BJ fibroblasts. These properties render comoclathrin an excellent development candidate as whitening agent.


Assuntos
Ascomicetos/metabolismo , Endófitos/metabolismo , Inibidores Enzimáticos/farmacologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Plantas/microbiologia , Preparações Clareadoras de Pele/farmacologia , Células A549 , Ascomicetos/genética , Sobrevivência Celular/efeitos dos fármacos , Clima Desértico , Endófitos/genética , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/toxicidade , Células Hep G2 , Humanos , Células MCF-7 , Metaboloma , Metabolômica , Monofenol Mono-Oxigenase/metabolismo , Filogenia , Preparações Clareadoras de Pele/isolamento & purificação , Preparações Clareadoras de Pele/toxicidade
9.
J Nat Prod ; 85(1): 25-33, 2022 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-35045259

RESUMO

The number of species in Aspergillus section Flavi has recently increased to 36 and includes some of the most important and well-known species in the genus Aspergillus. Numerous secondary metabolites, especially mycotoxins, have been reported from species such as A. flavus; however many of the more recently described species are less studied from a chemical point of view. This paper describes the use of MS/MS-based molecular networking to investigate the metabolome of A. caelatus leading to the discovery of several new diketopiperazine dimers and aspergillicins. An MS-guided isolation procedure yielded six new compounds, including asperazines D-H (1-5) and aspergillicin H (6). Asperazines G and H are artifacts derived from asperazines E and F formed during the separation process by formic acid. Two known compounds, aspergillicins A and C (7 and 8), were isolated from the same strain. Structures were elucidated by analyzing their HR-MS/MS and NMR spectroscopic data. The absolute configuration of asperazines D-F and aspergillicin H were deduced from the combination of NMR, Marfey's method, and ECD analyses.


Assuntos
Aspergillus/química , Depsipeptídeos/química , Dicetopiperazinas/química , Dimerização , Micotoxinas/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas em Tandem
10.
Nat Prod Res ; 36(6): 1668-1671, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33706628

RESUMO

Three known compounds were isolated from Virgaria nigra CF-231658; 2,7-dihydroxy naphthalene (1), virgaricin B (2) and virgaricin (3). The isolated compounds was obtained from liquid-state and agar-supported fermentation using Amberlite XAD-16 solid-phase extraction during the cultivation step. Their structures were elucidated on the basis of 1D and 2D NMR as well as HRMS spectroscopic analyses. The isolated compounds were examined for their ability to inhibit elastase using normal human diploid fibroblasts. Compound 2 displayed the most potent activity with 76.7 ± 2.12% inhibition of the enzyme activity at 5 µM concentration.


Assuntos
Ascomicetos , Ascomicetos/química , Fermentação , Humanos , Lactamas/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Elastase Pancreática/antagonistas & inibidores
11.
Malar J ; 20(1): 457, 2021 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-34865639

RESUMO

BACKGROUND: Malaria is a global health problem for which novel therapeutic compounds are needed. To this end, a recently published novel family of antiplasmodial macrolides, strasseriolides A-D, was herein subjected to in vivo efficacy studies and preclinical evaluation in order to identify the most promising candidate(s) for further development. METHODS: Preclinical evaluation of strasseriolides A-D was performed by MTT-based cytotoxicity assay in THLE-2 (CRL-2706) liver cells, cardiotoxicity screening using the FluxOR™ potassium assay in hERG expressed HEK cells, LC-MS-based analysis of drug-drug interaction involving CYP3A4, CYP2D6 and CYP2C9 isoforms inhibition and metabolic stability assays in human liver microsomes. Mice in vivo toxicity studies were also accomplished by i.v. administration of the compounds (vehicle: 0.5% HPMC, 0.5% Tween 80, 0.5% Benzyl alcohol) in mice at 25 mg/kg dosage. Plasma were prepared from mice blood samples obtained at different time points (over a 24-h period), and analysed by LC-MS to quantify compounds. The most promising compounds, strasseriolides C and D, were subjected to a preliminary in vivo efficacy study in which transgenic GFP-luciferase expressing Plasmodium berghei strain ANKA-infected Swiss Webster female mice (n = 4-5) were treated 48 h post-infection with an i.p. dosage of strasseriolide C at 50 mg/kg and strasseriolide D at 22 mg/kg for four days after which luciferase activity was quantified on day 5 in an IVIS® Lumina II imager. RESULTS: Strasseriolides A-D showed no cytotoxicity, no carditoxicity and no drug-drug interaction problems in vitro with varying intrinsic clearance (CLint). Only strasseriolide B was highly toxic to mice in vivo (even at 1 mg/kg i.v. dosage) and, therefore, discontinued in further in vivo studies. Strasseriolide D showed statistically significant activity in vivo giving rise to lower parasitaemia levels (70% lower) compared to the controls treated with vehicle. CONCLUSIONS: Animal efficacy and preclinical evaluation of the recently discovered potent antiplasmodial macrolides, strasseriolides A-D, led to the identification of strasseriolide D as the most promising compound for further development. Future studies dealing on structure optimization, formulation and establishment of optimal in vivo dosage explorations of this novel compound class could enhance their clinical potency and allow for progress to later stages of the developmental pipeline.


Assuntos
Antimaláricos , Ascomicetos/química , Macrolídeos , Malária/tratamento farmacológico , Plasmodium berghei/efeitos dos fármacos , Animais , Antimaláricos/química , Antimaláricos/farmacologia , Antimaláricos/toxicidade , Avaliação Pré-Clínica de Medicamentos , Feminino , Macrolídeos/química , Macrolídeos/farmacologia , Macrolídeos/toxicidade , Camundongos
12.
Molecules ; 26(14)2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34299537

RESUMO

Microbial natural products are an invaluable resource for the biotechnological industry. Genome mining studies have highlighted the huge biosynthetic potential of fungi, which is underexploited by standard fermentation conditions. Epigenetic effectors and/or cultivation-based approaches have successfully been applied to activate cryptic biosynthetic pathways in order to produce the chemical diversity suggested in available fungal genomes. The addition of Suberoylanilide Hydroxamic Acid to fermentation processes was evaluated to assess its effect on the metabolomic diversity of a taxonomically diverse fungal population. Here, metabolomic methodologies were implemented to identify changes in secondary metabolite profiles to determine the best fermentation conditions. The results confirmed previously described effects of the epigenetic modifier on the metabolism of a population of 232 wide diverse South Africa fungal strains cultured in different fermentation media where the induction of differential metabolites was observed. Furthermore, one solid-state fermentation (BRFT medium), two classic successful liquid fermentation media (LSFM and YES) and two new liquid media formulations (MCKX and SMK-II) were compared to identify the most productive conditions for the different populations of taxonomic subgroups.


Assuntos
Epigênese Genética/genética , Fungos/genética , Folhas de Planta/microbiologia , Produtos Biológicos/metabolismo , Vias Biossintéticas/genética , Biotecnologia/métodos , Meios de Cultura/metabolismo , Fermentação/genética , Genoma Fúngico/genética , Metabolômica/métodos , África do Sul
13.
Pharmaceuticals (Basel) ; 14(3)2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33809512

RESUMO

A novel cyclic antimalarial and antitrypanosome hexapeptide, pipecolisporin (1), was isolated from cultures of Nigrospora oryzae CF-298113, a fungal endophyte isolated from roots of Triticum sp. collected in a traditional agricultural land of Montefrío, Granada, Spain. The structure of this compound, including its absolute configuration, was elucidated by HRMS, 1-D and 2-D NMR spectroscopy, and Marfey's analysis. This metabolite displayed interesting activity against Plasmodium falciparum and Trypanosoma cruzi, with IC50 values in the micromolar range, and no significant cytotoxicity against the human cancer cell lines A549, A2058, MCF7, MIA PaCa-2, and HepG2.

14.
Org Lett ; 22(17): 6709-6713, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32808790

RESUMO

A novel family of four potent antimalarial macrolides, strasseriolides A-D (1-4), has been isolated from cultures of Strasseria geniculata CF-247251, a fungal strain obtained from plant tissues. The structures of these compounds, including their absolute configurations, were elucidated by HRMS, NMR spectroscopy, and X-ray single-crystal diffraction. The four compounds gave respective IC50 values of 9.810, 0.013, 0.123, and 0.128 µM against Plasmodium falciparum 3D7 parasites with no significant cytotoxicity against the HepG2 cell line.


Assuntos
Antibacterianos/farmacologia , Antimaláricos/farmacologia , Macrolídeos/farmacologia , Inibidores da Síntese de Proteínas/análise , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antimaláricos/química , Antimaláricos/isolamento & purificação , Ascomicetos , Fungos , Macrolídeos/química , Macrolídeos/isolamento & purificação , Estrutura Molecular , Inibidores da Síntese de Proteínas/química
15.
Antibiotics (Basel) ; 9(6)2020 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-32466351

RESUMO

An antifungal lipodepsipeptide was obtained from cultures of the fungus Foliophoma fallens CF-236885. Its structure, elucidated by HRMS and NMR spectroscopy, contained Gly, Thr, Asn, ß-Ala, Orn, Ala, two Ser residues, and 3-hydroxy-4-methylhexadecanoic acid. The absolute configuration of its amino acid residues was determined using Marfey's analysis and J-based configuration analysis helped to establish the relative configuration of the 3-hydroxy-4-methylhexadecanoic acid moiety. A literature search retrieved a patent describing antibiotic TKR2999 (1), whose non-disclosed structure was confirmed to be identical to that found for our compound, according to its physicochemical properties and NMR spectra. Compound 1 displayed potent antifungal activity against Aspergillus fumigatus and a panel of Candida strains.

16.
Molecules ; 25(3)2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32033190

RESUMO

Abstract: A main cellular functional module that becomes dysfunctional during aging is the proteostasis network. In the present study, we show that benzoic acid derivatives isolated from Bjerkandera adusta promote the activity of the two main protein degradation systems, namely the ubiquitin-proteasome (UPP) and especially the autophagy-lysosome pathway (ALP) in human foreskin fibroblasts. Our findings were further supported by in silico studies, where all compounds were found to be putative binders of both cathepsins B and L. Among them, compound 3 (3-chloro-4-methoxybenzoic acid) showed the most potent interaction with both enzymes, which justifies the strong activation of cathepsins B and L (467.3 ± 3.9%) on cell-based assays. Considering that the activity of both the UPP and ALP pathways decreases with aging, our results suggest that the hydroxybenzoic acid scaffold could be considered as a promising candidate for the development of novel modulators of the proteostasis network, and likely of anti-aging agents.


Assuntos
Autofagia/fisiologia , Coriolaceae/química , Hidroxibenzoatos/farmacologia , Lisossomos/fisiologia , Proteostase/efeitos dos fármacos , Ácido Benzoico/farmacologia , Catepsinas/metabolismo , Extratos Celulares/farmacologia , Linhagem Celular , Coriolaceae/metabolismo , Humanos , Hidroxibenzoatos/química , Simulação de Acoplamento Molecular , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Ubiquitina-Proteína Ligases/metabolismo
17.
Metabolites ; 9(10)2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31546616

RESUMO

Fungi are one of the most prolific sources of microbial secondary metabolites. The production of new metabolites can be achieved using multiple fermentation conditions and by adding small-molecule effectors, including epigenetic modifiers. In the framework of our Natural Product screening programme targeting the discovery of new antimicrobial compounds, we applied multiple fermentation conditions and adsorptive polymeric resins on a large collection of fungal endophytes, to increase and stimulate their fungal secondary metabolite production. During this work the endophytic fungus Dimorphosporicola tragani CF-090383 showed antimicrobial activity only when grown in presence of adsorptive polymeric resins. In addition, seven epigenetic modifiers were added to fermentations of this endophytic fungus, in an attempt to activate its cryptic pathways as well as to analyse the metabolites produced under these conditions. D. tragani was seen to produce three different mycotoxin dendrodolides when the epigenetic modifiers 5-azacytidine and valproic acid were added to the fermentations, and these compounds were further characterized. However, the fungus produced the fatty acid synthesis inhibitor cerulenin, a molecule not previously described to be produced by this fungal species, only when cultivated in presence of the XAD-16 resin. We have found that the addition of XAD-16 resin resulted in four-fold higher titers in the production of cerulenin when compared to the best production conditions described in literature for the original fungal producer strain, Cephalosporium caerulens KF-140 (=Sarocladium oryzae), in a zeolite-based fermentation, used as an ammonium ion-trapping agent. The production of cerulenin by this strain of D. tragani, represents an alternative source for the improved production of cerulenin with better yields.

18.
J Biotechnol ; 301: 88-96, 2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-31152756

RESUMO

From a large screening of microbial extracts for the discovery of proteasome modulating natural products, the fungal strain Cercospora sp. (CF-223709) was selected as the most promising for further investigation. Different liquid cultures of the strain were initially screened for their anti-oxidant activity (DPPH, ABTS) and for their cytotoxicity against the A2058, HepG2 and CCD25sk cell lines. A detailed chemical analysis and evaluation of the capacity to activate 26S-proteasome was followed for the most active extract. Three main polyketides were isolated and characterized by extensive analysis of NMR and HRMS spectra data as penialidine F (1), fulvic acid (2), and SB238569 (3). Fulvic acid showed the most significant anti-oxidant activity. Its IC50 value (8.16 µM) against the ABTS radical resulted 3-fold lower than the standard trolox. Fulvic acid also demonstrated a significant effect on proteasome by enhancing the chymotrypsin- and caspase-like activities of the 26S proteasome of human fibroblasts by 71.43% and 37.5% at 1 µM, respectively. Furthermore by scaling up the culture in a 30 L submerged bioreactor, Cercospora sp. produced up to 162.6 ±â€¯1.3 mg of fulvic acid/L. Our findings suggest that CF-223709 can be a promising source of proteasome activating natural compounds.


Assuntos
Ascomicetos/metabolismo , Produtos Biológicos , Reatores Biológicos/microbiologia , Policetídeos , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Antioxidantes , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Complexo de Endopeptidases do Proteassoma/metabolismo
19.
BMC Syst Biol ; 12(Suppl 5): 99, 2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30458793

RESUMO

BACKGROUND: Spatial localization of natural products or proteins during microbial interactions can help to identify new antimicrobials both as offensive or defensive agents. Visible spatial interactions have been used for decades to enhance Drug Discovery processes both in industry and academia. RESULTS: Herein we describe an automated micro-extraction methodology, that coupled with the previously described HPLC-Studio 2.0 software and the new development, the MASS-Studio 1.0 software, can combine multiple chemical analyses to generate ultraviolet (UV) and mass spectrometry (MS) images from traditional affordable analytical equipment. As a proof of concept, we applied this methodology on two microbial antagonisms observed among co-habitant endophytes isolated from endemic plants of arid areas of the south of Europe. CONCLUSIONS: The use of UV and MS images highlighted interacting naturals products and allowed clear identification of induced molecules of interest not produced by the strains when cultured individually.


Assuntos
Anti-Infecciosos/química , Descoberta de Drogas/métodos , Interações Microbianas , Anti-Infecciosos/metabolismo , Bactérias/crescimento & desenvolvimento , Técnicas de Cocultura , Espectrometria de Massas , Estudo de Prova de Conceito , Raios Ultravioleta
20.
Sci Rep ; 8(1): 9729, 2018 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-29950656

RESUMO

Native plant communities from arid areas present distinctive characteristics to survive in extreme conditions. The large number of poorly studied endemic plants represents a unique potential source for the discovery of novel fungal symbionts as well as host-specific endophytes not yet described. The addition of adsorptive polymeric resins in fungal fermentations has been seen to promote the production of new secondary metabolites and is a tool used consistently to generate new compounds with potential biological activities. A total of 349 fungal strains isolated from 63 selected plant species from arid ecosystems located in the southeast of the Iberian Peninsula, were characterized morphologically as well as based on their ITS/28S ribosomal gene sequences. The fungal community isolated was distributed among 19 orders including Basidiomycetes and Ascomycetes, being Pleosporales the most abundant order. In total, 107 different genera were identified being Neocamarosporium the genus most frequently isolated from these plants, followed by Preussia and Alternaria. Strains were grown in four different media in presence and absence of selected resins to promote chemical diversity generation of new secondary metabolites. Fermentation extracts were evaluated, looking for new antifungal activities against plant and human fungal pathogens, as well as, cytotoxic activities against the human liver cancer cell line HepG2. From the 349 isolates tested, 126 (36%) exhibited significant bioactivities including 58 strains with exclusive antifungal properties and 33 strains with exclusive activity against the HepG2 hepatocellular carcinoma cell line. After LCMS analysis, 68 known bioactive secondary metabolites could be identified as produced by 96 strains, and 12 likely unknown compounds were found in a subset of 14 fungal endophytes. The chemical profiles of the differential expression of induced activities were compared. As proof of concept, ten active secondary metabolites only produced in the presence of resins were purified and identified. The structures of three of these compounds were new and herein are elucidated.


Assuntos
Antifúngicos/metabolismo , Antineoplásicos/metabolismo , Plantas/microbiologia , Alternaria/metabolismo , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Ascomicetos/metabolismo , Ascomicetos/fisiologia , Basidiomycota/metabolismo , Basidiomycota/fisiologia , Ecossistema , Células Hep G2 , Humanos , Testes de Sensibilidade Microbiana , Filogenia
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