RESUMO
Bacteria have evolved various strategies to combat heavy metal stress, including the secretion of small molecules, known as metallophores. These molecules hold a potential role in the mitigation of toxic metal contamination from the environment (bioremediation). Herein, we employed combined comparative metabolomic and genomic analyses to study the metallophores excreted by Delftia lacustris DSM 21246. LCMS-metabolomic analysis of this bacterium cultured under iron limitation led to a suite of lipophilic metallophores exclusively secreted in response to iron starvation. Additionally, we conducted genome sequencing of the DSM 21246 strain using nanopore sequencing technology and employed antiSMASH to mine the genome, leading to the identification of a biosynthetic gene cluster (BGC) matching the known BGC responsible for delftibactin A production. The isolated suite of amphiphilic metallophores, termed delftibactins C-F (1-4), was characterized using various chromatographic, spectroscopic, and bioinformatic techniques. The planar structure of these compounds was elucidated through 1D and 2D NMR analyses, as well as LCMS/MS-based fragmentation studies. Notably, their structures differed from previously known delftibactins due to the presence of a lipid tail. Marfey's and bioinformatic analyses were employed to determine the absolute configuration of the peptide scaffold. Delftibactin A, a previously identified metallophore, has exhibited a gold biomineralizing property; compound 1 was tested for and also demonstrated this property.
Assuntos
Delftia , Delftia/metabolismo , Delftia/genética , Estrutura Molecular , Metabolômica/métodos , Genoma Bacteriano , Família MultigênicaRESUMO
The tropical marine cyanobacterium Moorena producens JHB is a prolific source of secondary metabolites with potential biomedical utility. Previous studies on this strain led to the discovery of several novel compounds such as hectochlorins and jamaicamides. However, bioinformatic analyses of its genome indicate the presence of numerous cryptic biosynthetic gene clusters that have yet to be characterized. To potentially stimulate the production of novel compounds from this strain, it was cocultured with Candida albicans. From this experiment, we observed the increased production of a new compound that we characterize here as hectoramide B. Bioinformatic analysis of the M. producens JHB genome enabled the identification of a putative biosynthetic gene cluster responsible for hectoramide B biosynthesis. This work demonstrates that coculture competition experiments can be a valuable method to facilitate the discovery of novel natural products from cyanobacteria.
Assuntos
Cianobactérias , Depsipeptídeos , Candida albicans/genética , Técnicas de Cocultura , Cianobactérias/química , Depsipeptídeos/metabolismo , Família MultigênicaRESUMO
Constructed treatment wetlands are commonly used to enhance surface water nutrient removal following traditional wastewater treatment. However, the constant inflow may necessitate continuous wetland inundation, leading to persistent anaerobic conditions and the accumulation of organic matter (OM) as suspended detrital flocculent (floc) and soil OM. This study investigated if temporary water level draw-down (WLDD) could promote OM consolidation and oxidation without impacting nutrient removal efficiency. A large-scale, 2-y, before-after-control-impact field experiment at the Orlando Easterly Wetland (Christmas, FL, USA) was complemented by an intact soil core laboratory experiment with varied WLDD regimes. Changes in floc thickness, soil elevation, and surface water and soil nutrients were quantified. Field experiment results demonstrated an average floc thickness reduction of 60 % and soil elevation decline of 2.7 cm persisted after return to normal flow operation. This reduction was achieved with one â¼3-week dry event for two consecutive years and removed an estimated 7.5 years' worth of accumulated floc. Intact soil core results showed a direct relationship (R2 = 0.93) between days of WLDD and cumulative CO2-C loss, despite oxidation only accounting for 4-5 % of OM loss (and consolidation accounting for the remaining 95-96 %). While soil nitrogen (N) and phosphorus (P) concentrations did tend to increase during WLDD, outflow surface water N was not affected by the WLDD. Soluble reactive P increased for â¼36 days following reflooding, then returned to baseline. Incorporating WLDD into wetland management every few years could significantly reduce the frequency of costly cell renovation projects aimed at removing accumulated OM.
RESUMO
Cupriavidus necator H16 is known to be a rich source of linear lipopeptide siderophores when grown under iron-depleted conditions; prior literature termed these compounds cupriachelins. These small molecules bear ß-hydroxyaspartate moieties that contribute to a photoreduction of iron when bound as ferric cupriachelin. Here, we present structural assignment of cupriachelins from C. necator B-4383 grown under iron limitation. The characterization of B-4383 cupriachelins is based on MS/MS fragmentation analysis, which was confirmed by 1D- and 2D-NMR for the most abundant analog (1). The cupriachelin congeners distinguish these two strains with differences in the preferred lipid tail; however, our rigorous metabolomic investigation also revealed minor analogs with changes in the peptide core, hinting at a potential mechanism by which these siderophores may reduce biologically unavailable ferric iron (4-6). Antifungal screening of the C. necator B-4383 supernatant extract and the isolated cupriachelin analog (1) revealed inhibitory activity against Cryptococcus neoformans, with IC50 values of 16.6 and 3.2 µg/mL, respectively. This antifungal activity could be explained by the critical role of the iron acquisition pathway in the growth and pathogenesis of the C. neoformans fungal pathogen.
RESUMO
The tropical marine cyanobacterium Moorena producens JHB is a prolific source of secondary metabolites with potential biomedical utility. Previous studies of this strain led to the discovery of several novel compounds such as the hectochlorins and jamaicamides; however, bioinformatic analyses of its genome suggested that there were many more cryptic biosynthetic gene clusters yet to be characterized. To potentially stimulate the production of novel compounds from this strain, it was co-cultured with Candida albicans. From this experiment, we observed the increased production of a new compound that we characterize here as hectoramide B. Bioinformatic analysis of the M. producens JHB genome enabled the identification of a putative biosynthetic gene cluster responsible for hectoramide B biosynthesis. This work demonstrates that co-culture competition experiments can be a valuable method to facilitate the discovery of novel natural products from cyanobacteria.
RESUMO
Luquilloamides A-G (1-7) were isolated from a small environmental collection of a marine cyanobacterium found growing on eelgrass (Zostera sp.) near Luquillo, Puerto Rico. Structure elucidation of the luquilloamides was accomplished via detailed NMR and MS analyses, and absolute configurations were determined using a combination of advanced Mosher's method, J-based configuration analysis, semisynthetic fragment analysis derived from ozonolysis, methylation, Baeyer-Villiger oxidation, Mosher's esterification, specific rotations, and ECD data. Except for 2, the luquilloamides share a characteristic tert-butyl-containing polyketide fragment, ß-alanine, and a proposed highly modified polyketide extension. While compound 1 is a linear lipopeptide with two α-methyl branches and a vinyl chloride functionality in the polyketide portion, compounds 4, 6, and 7 possess a cyclohexanone structure with methylation on the α- or ß-positions of the polyketide as well as an acetyl group. Interestingly, the absolute configuration at C-5 and C-6 on the cyclohexanone unit in 7 is opposite to that of 4-6. Compound 3 was revealed to have a tert-butyl-containing polyketide, ß-alanine, and a PKS/NRPS-derived γ-isopropyl pyrrolinone. Compound 2 may be a hydrolysis product of 3. Of the seven new compounds, 1 showed the most potent cytotoxicity to human H-460 lung cancer cells.
Assuntos
Lipopeptídeos/farmacologia , Oscillatoria , Linhagem Celular Tumoral , Humanos , Biologia Marinha , Estrutura Molecular , Oscillatoria/química , Porto RicoRESUMO
Vegetation transitions occur globally, altering ecosystem processing of organic matter and changing rates of soil biogeochemical cycling. In coastal marshes, more salt- and inundation-tolerant herbaceous species are encroaching on less tolerant species, concomitant with sea level rise. These species shifts could disrupt ecosystem services such as soil organic matter storage and the cycling of carbon (C), nitrogen (N), and phosphorus (P). To determine how these ecosystem processes were affected by encroachment, we characterized biogeochemical properties and functions along a transect of encroaching Distichlis spicata L. Greene (saltgrass) on Spartina bakeri Merr. (cordgrass), two herbaceous species. During both the wet and dry season, nine soil cores were obtained from three community types: saltgrass end member, transition zone, and cordgrass end member. Total soil C, N, and organic matter were greatest within the saltgrass and transition zones. The saltgrass and transition zone soils also supported higher rates of enzyme activity and potentially mineralizable N and P than cordgrass soils during the dry season, and greater potential CO2 production and microbial biomass C during the wet season. Generally, the transition zone functioned similarly to the saltgrass zone and the encroachment gradient coincided with a 33 cm elevation change. Seasonally, low extractable nutrient availability (nitrate and soluble reactive phosphorus) during the dry season was correlated with overall greater enzyme activity (N-acetyl-ß-D-glucosidase, alkaline phosphatase, ß-glucosidase, xylosidase, and cellobiosidase) and potentially mineralizable N and phosphorus (P) rates. This study demonstrates that shifts in dominant herbaceous species and accompanying abiotic gradients alters biogeochemical processing of organic matter within coastal marshes.
Assuntos
Solo , Áreas Alagadas , Ecossistema , Nitrogênio , FósforoRESUMO
Gallinamide A, originally isolated with a modest antimalarial activity, was subsequently reisolated and characterized as a potent, selective, and irreversible inhibitor of the human cysteine protease cathepsin L. Molecular docking identified potential modifications to improve binding, which were synthesized as a suite of analogs. Resultingly, this current study produced the most potent gallinamide analog yet tested against cathepsin L (10, Ki = 0.0937 ± 0.01 nM and kinact/Ki = 8â¯730â¯000). From a protein structure and substrate preference perspective, cruzain, an essential Trypanosoma cruzi cysteine protease, is highly homologous. Our investigations revealed that gallinamide and its analogs potently inhibit cruzain and are exquisitely toxic toward T. cruzi in the intracellular amastigote stage. The most active compound, 5, had an IC50 = 5.1 ± 1.4 nM, but was relatively inactive to both the epimastigote (insect stage) and the host cell, and thus represents a new candidate for the treatment of Chagas disease.
Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Catepsina L/antagonistas & inibidores , Inibidores de Cisteína Proteinase/química , Inibidores de Cisteína Proteinase/farmacologia , Desenho de Fármacos , Proteínas de Protozoários/antagonistas & inibidores , Trypanosoma cruzi/enzimologia , Cisteína Endopeptidases , Humanos , Cinética , Simulação de Acoplamento MolecularRESUMO
Certain commensal and pathogenic bacteria produce colibactin, a small-molecule genotoxin that causes interstrand cross-links in host cell DNA. Although colibactin alkylates DNA, the molecular basis for cross-link formation is unclear. Here, we report that the colibactin biosynthetic enzyme ClbL is an amide bond-forming enzyme that links aminoketone and ß-keto thioester substrates in vitro and in vivo. The substrate specificity of ClbL strongly supports a role for this enzyme in terminating the colibactin NRPS-PKS assembly line and incorporating two electrophilic cyclopropane warheads into the final natural product scaffold. This proposed transformation was supported by the detection of a colibactin-derived cross-linked DNA adduct. Overall, this work provides a biosynthetic explanation for colibactin's DNA cross-linking activity and paves the way for further study of its chemical structure and biological roles.
Assuntos
Amidoidrolases/metabolismo , DNA Bacteriano/metabolismo , Proteínas de Escherichia coli/metabolismo , Peptídeos/metabolismo , Policetídeos/metabolismo , Amidoidrolases/química , Domínio Catalítico , Ciclopropanos/química , Ciclopropanos/metabolismo , DNA Bacteriano/química , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Mutação , Peptídeo Hidrolases/genética , Peptídeo Hidrolases/metabolismo , Especificidade por SubstratoRESUMO
Certain Escherichia coli strains residing in the human gut produce colibactin, a small-molecule genotoxin implicated in colorectal cancer pathogenesis. However, colibactin's chemical structure and the molecular mechanism underlying its genotoxic effects have remained unknown for more than a decade. Here we combine an untargeted DNA adductomics approach with chemical synthesis to identify and characterize a covalent DNA modification from human cell lines treated with colibactin-producing E. coli Our data establish that colibactin alkylates DNA with an unusual electrophilic cyclopropane. We show that this metabolite is formed in mice colonized by colibactin-producing E. coli and is likely derived from an initially formed, unstable colibactin-DNA adduct. Our findings reveal a potential biomarker for colibactin exposure and provide mechanistic insights into how a gut microbe may contribute to colorectal carcinogenesis.
Assuntos
Carcinogênese/metabolismo , Neoplasias Colorretais/microbiologia , Ciclopropanos/metabolismo , Adutos de DNA/metabolismo , Dano ao DNA , Escherichia coli/metabolismo , Microbioma Gastrointestinal , Mutagênicos/metabolismo , Peptídeos/metabolismo , Policetídeos/metabolismo , Alquilantes , Alquilação , Animais , Carcinogênese/genética , Neoplasias Colorretais/genética , Ciclopropanos/química , Escherichia coli/patogenicidade , Vida Livre de Germes , Células HT29 , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Mutagênicos/toxicidade , Peptídeos/química , Peptídeos/toxicidade , Policetídeos/química , Policetídeos/toxicidadeRESUMO
The cyanobacterial marine natural product honaucin A inhibits mammalian innate inflammation in vitro and in vivo. To decipher its mechanism of action, RNA sequencing was used to evaluate differences in gene expression of cultured macrophages following honaucin A treatment. This analysis led to the hypothesis that honaucin A exerts its anti-inflammatory activity through activation of the cytoprotective nuclear erythroid 2-related factor 2 (Nrf2)-antioxidant response element/electrophile response element (ARE/EpRE) signaling pathway. Activation of this pathway by honaucin A in cultured human MCF7 cells was confirmed using an Nrf2 luciferase reporter assay. In vitro alkylation experiments with the natural product and N-acetyl-l-cysteine suggest that honaucin A activates this pathway through covalent interaction with the sulfhydryl residues of the cytosolic repressor protein Keap1. Honaucin A presents a potential therapeutic lead for diseases with an inflammatory component modulated by Nrf2-ARE.
Assuntos
Anti-Inflamatórios/farmacologia , Organismos Aquáticos/química , Produtos Biológicos/farmacologia , Inflamação/tratamento farmacológico , Fator 2 Relacionado a NF-E2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Alquilação/efeitos dos fármacos , Animais , Anti-Inflamatórios/química , Antioxidantes/metabolismo , Produtos Biológicos/química , Linhagem Celular , Linhagem Celular Tumoral , Citoproteção/efeitos dos fármacos , Feminino , Humanos , Inflamação/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Células MCF-7 , Camundongos , Células RAW 264.7RESUMO
Integrating LC-MS/MS molecular networking and bioassay-guided fractionation enabled the targeted isolation of a new and bioactive cyclic octapeptide, samoamide A (1), from a sample of cf. Symploca sp. collected in American Samoa. The structure of 1 was established by detailed 1D and 2D NMR experiments, HRESIMS data, and chemical degradation/chromatographic (e.g., Marfey's analysis) studies. Pure compound 1 was shown to have in vitro cytotoxic activity against several human cancer cell lines in both traditional cell culture and zone inhibition bioassays. Although there was no particular selectivity between the cell lines tested for samoamide A, the most potent activity was observed against H460 human non-small-cell lung cancer cells (IC50 = 1.1 µM). Molecular modeling studies suggested that one possible mechanism of action for 1 is the inhibition of the enzyme dipeptidyl peptidase (CD26, DPP4) at a reported allosteric binding site, which could lead to many downstream pharmacological effects. However, this interaction was moderate when tested in vitro at up to 10 µM and only resulted in about 16% peptidase inhibition. Combining bioassay screening with the cheminformatics strategy of LC-MS/MS molecular networking as a discovery tool expedited the targeted isolation of a natural product possessing both a novel chemical structure and a desired biological activity.
Assuntos
Cianobactérias/química , Peptídeos Cíclicos/isolamento & purificação , Peptídeos Cíclicos/farmacologia , Samoa Americana , Carcinoma Pulmonar de Células não Pequenas , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Neoplasias Pulmonares , Biologia Marinha , Modelos Moleculares , Estrutura Molecular , Peptídeos Cíclicos/químicaRESUMO
The potential of the diverse chemistries present in natural products (NP) for biotechnology and medicine remains untapped because NP databases are not searchable with raw data and the NP community has no way to share data other than in published papers. Although mass spectrometry (MS) techniques are well-suited to high-throughput characterization of NP, there is a pressing need for an infrastructure to enable sharing and curation of data. We present Global Natural Products Social Molecular Networking (GNPS; http://gnps.ucsd.edu), an open-access knowledge base for community-wide organization and sharing of raw, processed or identified tandem mass (MS/MS) spectrometry data. In GNPS, crowdsourced curation of freely available community-wide reference MS libraries will underpin improved annotations. Data-driven social-networking should facilitate identification of spectra and foster collaborations. We also introduce the concept of 'living data' through continuous reanalysis of deposited data.
Assuntos
Produtos Biológicos/química , Produtos Biológicos/classificação , Curadoria de Dados/métodos , Bases de Dados de Compostos Químicos , Disseminação de Informação/métodos , Espectrometria de Massas/estatística & dados numéricos , Sistemas de Gerenciamento de Base de Dados , Armazenamento e Recuperação da Informação/métodos , InternacionalidadeRESUMO
A two-stage "tandem strategy" for the regiocontrolled synthesis of very highly substituted quinolines is described. Benzannulation based on the reaction of cyclobutenones or diazo ketones with N-propargyl-substituted ynamides proceeds via a cascade of several pericyclic reactions to generate multiply substituted aniline derivatives. In the second stage of the tandem strategy, triflate derivatives of the phenolic benzannulation products undergo Larock cyclization upon exposure to iodine to form products that are further elaborated by methods such as palladium-catalyzed coupling to generate quinolines that can be substituted at every position of the bicyclic system.
Assuntos
Derivados de Benzeno/química , Quinolinas/síntese química , Catálise , Ciclização , Estrutura Molecular , Quinolinas/químicaRESUMO
Moorea producens JHB, a Jamaican strain of tropical filamentous marine cyanobacteria, has been extensively studied by traditional natural products techniques. These previous bioassay and structure guided isolations led to the discovery of two exciting classes of natural products, hectochlorin (1) and jamaicamides A (2) and B (3). In the current study, mass spectrometry-based 'molecular networking' was used to visualize the metabolome of Moorea producens JHB, and both guided and enhanced the isolation workflow, revealing additional metabolites in these compound classes. Further, we developed additional insight into the metabolic capabilities of this strain by genome sequencing analysis, which subsequently led to the isolation of a compound unrelated to the jamaicamide and hectochlorin families. Another approach involved stimulation of the biosynthesis of a minor jamaicamide metabolite by cultivation in modified media, and provided insights about the underlying biosynthetic machinery as well as preliminary structure-activity information within this structure class. This study demonstrated that these orthogonal approaches are complementary and enrich secondary metabolomic coverage even in an extensively studied bacterial strain.
Assuntos
Produtos Biológicos/química , Cianobactérias/metabolismo , Genoma Bacteriano , Redes e Vias Metabólicas/genética , Metaboloma , Metabolômica/métodos , Cianobactérias/genética , Cianobactérias/crescimento & desenvolvimento , DNA Bacteriano/genética , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Biologia Marinha , Espectrometria de Massas , Dados de Sequência Molecular , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Análise de Sequência de DNA , Fluxo de TrabalhoRESUMO
Bastimolide A (1), a polyhydroxy macrolide with a 40-membered ring, was isolated from a new genus of the tropical marine cyanobacterium Okeania hirsuta. This novel macrolide was defined by spectroscopy and chemical reactions to possess one 1,3-diol, one 1,3,5-triol, six 1,5-diols, and one tert-butyl group; however, the relationships of these moieties to one another were obscured by a highly degenerate (1)H NMR spectrum. Its complete structure and absolute configuration were therefore unambiguously determined by X-ray diffraction analysis of the nona-p-nitrobenzoate derivative (1d). Pure bastimolide A (1) showed potent antimalarial activity against four resistant strains of Plasmodium falciparum with IC50 values between 80 and 270 nM, although with some toxicity to the control Vero cells (IC50 = 2.1 µM), and thus represents a potentially promising lead for antimalarial drug discovery. Moreover, rigorous establishment of its molecular arrangement gives fresh insight into the structures and biosynthesis of cyanobacterial polyhydroxymacrolides.
Assuntos
Antimaláricos/farmacologia , Cianobactérias/química , Macrolídeos/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Antimaláricos/química , Antimaláricos/isolamento & purificação , Resistência a Medicamentos , Macrolídeos/química , Macrolídeos/isolamento & purificação , Conformação Molecular , Testes de Sensibilidade Parasitária , Relação Estrutura-AtividadeRESUMO
Coral reefs are intricate ecosystems that harbor diverse organisms, including 25% of all marine fish. Healthy corals exhibit a complex symbiosis between coral polyps, endosymbiotic alga, and an array of microorganisms, called the coral holobiont. Secretion of specialized metabolites by coral microbiota is thought to contribute to the defense of this sessile organism against harmful biotic and abiotic factors. While few causative agents of coral diseases have been unequivocally identified, fungi have been implicated in the massive destruction of some soft corals worldwide. Because corals are nocturnal feeders, they may be more vulnerable to fungal infection at night, and we hypothesized that the coral microbiota would have the capability to enhance their defenses against fungi in the dark. A Pseudoalteromonas sp. isolated from a healthy octocoral displayed light-dependent antifungal properties when grown adjacent to Penicillium citrinum (P. citrinum) isolated from a diseased Gorgonian octocoral. Microbial MALDI-imaging mass spectrometry (IMS) coupled with molecular network analyses revealed that Pseudoalteromonas produced higher levels of antifungal polyketide alteramides in the dark than in the light. The alteramides were inactivated by light through a photoinduced intramolecular cyclization. Further NMR studies led to a revision of the stereochemical structure of the alteramides. Alteramide A exhibited antifungal properties and elicited changes in fungal metabolite distributions of mycotoxin citrinin and citrinadins. These data support the hypothesis that coral microbiota use abiotic factors such as light to regulate the production of metabolites with specialized functions to combat opportunistic pathogens at night.
Assuntos
Antozoários/microbiologia , Antifúngicos/farmacologia , Fungos/efeitos dos fármacos , Luz , Microbiota , Pseudoalteromonas/isolamento & purificação , Simbiose/fisiologia , Animais , Antifúngicos/isolamento & purificação , Dados de Sequência Molecular , Pseudoalteromonas/crescimento & desenvolvimento , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
A collection of the tropical marine cyanobacterium Symploca sp., collected near Kimbe Bay, Papua New Guinea, previously yielded several new metabolites including kimbeamides A-C, kimbelactone A, and tasihalide C. Investigations into a more polar cytotoxic fraction yielded three new lipopeptides, tasiamides C-E (1-3). The planar structures were deduced by 2D NMR spectroscopy and tandem mass spectrometry, and their absolute configurations were determined by a combination of Marfey's and chiral-phase GC-MS analysis. These new metabolites are similar to several previously isolated compounds, including tasiamide (4), grassystatins (5, 6), and symplocin A, all of which were isolated from similar filamentous marine cyanobacteria.
Assuntos
Cianobactérias/química , Lipopeptídeos/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Lipopeptídeos/química , Biologia Marinha , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Oligopeptídeos , Papua Nova GuinéRESUMO
Most (75%) of the anti-infectives that save countless lives and enormously improve quality of life originate from microbes found in nature. Herein, we described a global visualization of the detectable molecules produced from a single microorganism, which we define as the 'molecular network' of that organism, followed by studies to characterize the cellular effects of antibacterial molecules. We demonstrate that Streptomyces roseosporus produces at least four non-ribosomal peptide synthetase-derived molecular families and their gene subnetworks (daptomycin, arylomycin, napsamycin and stenothricin) were identified with different modes of action. A number of previously unreported analogs involving truncation, glycosylation, hydrolysis and biosynthetic intermediates and/or shunt products were also captured and visualized by creation of a map through MS/MS networking. The diversity of antibacterial compounds produced by S. roseosporus highlights the importance of developing new approaches to characterize the molecular capacity of an organism in a more global manner. This allows one to more deeply interrogate the biosynthetic capacities of microorganisms with the goal to streamline the discovery pipeline for biotechnological applications in agriculture and medicine. This is a contribution to a special issue to honor Chris Walsh's amazing career.
Assuntos
Antibacterianos/biossíntese , Genoma Bacteriano , Genômica/métodos , Streptomyces/genética , Espectrometria de Massas em Tandem/métodos , Biotecnologia/métodos , Mineração de Dados , Glicosilação , Hidrólise , Família MultigênicaRESUMO
A major goal in natural product discovery programs is to rapidly dereplicate known entities from complex biological extracts. We demonstrate here that molecular networking, an approach that organizes MS/MS data based on chemical similarity, is a powerful complement to traditional dereplication strategies. Successful dereplication with molecular networks requires MS/MS spectra of the natural product mixture along with MS/MS spectra of known standards, synthetic compounds, or well-characterized organisms, preferably organized into robust databases. This approach can accommodate different ionization platforms, enabling cross correlations of MS/MS data from ambient ionization, direct infusion, and LC-based methods. Molecular networking not only dereplicates known molecules from complex mixtures, it also captures related analogues, a challenge for many other dereplication strategies. To illustrate its utility as a dereplication tool, we apply mass spectrometry-based molecular networking to a diverse array of marine and terrestrial microbial samples, illustrating the dereplication of 58 molecules including analogues.