RESUMO
N6-methyladenosine (6mA) is a DNA modification that has recently been found to play regulatory roles during mammalian early embryo development and mitochondrial transcription. We found that a dioxygenase CcTet from the fungus Coprinopsis cinerea is also a dsDNA 6mA demethylase. It oxidizes 6mA to the intermediate N6-hydroxymethyladenosine (6hmA) with robust activity of 6mA-containing duplex DNA (dsDNA) as well as isolated genomics DNA. Structural characterization revealed that CcTet utilizes three flexible loop regions and two key residues-D337 and G331-in the active pocket to preferentially recognize substrates on dsDNA. A CcTet D337F mutant protein retained the catalytic activity on 6mA but lost activity on 5-methylcytosine. Our findings uncovered a 6mA demethylase that works on dsDNA, suggesting potential 6mA demethylation in fungi and elucidating 6mA recognition and the catalytic mechanism of CcTet. The CcTet D337F mutant protein also provides a chemical biology tool for future functional manipulation of DNA 6mA in vivo.
Assuntos
Dioxigenases , Eucariotos , 5-Metilcitosina/metabolismo , Animais , DNA/metabolismo , Metilação de DNA , Dioxigenases/metabolismo , Eucariotos/metabolismo , Mamíferos/genética , Proteínas Mutantes/genéticaRESUMO
BACKGROUND: Natural tetramates are a family of hybrid polyketides bearing tetramic acid (pyrrolidine-2,4-dione) moiety exhibiting a broad range of bioactivities. Biosynthesis of tetramates in microorganisms is normally directed by hybrid polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) machineries, which form the tetramic acid ring by recruiting trans- or cis-acting thioesterase-like Dieckmann cyclase in bacteria. There are a group of tetramates with unique skeleton of 3-(2H-pyran-2-ylidene)pyrrolidine-2,4-dione, which remain to be investigated for their biosynthetic logics. RESULTS: Herein, the tetramate type compounds bripiodionen (BPD) and its new analog, featuring the rare skeleton of 3-(2H-pyran-2-ylidene)pyrrolidine-2,4-dione, were discovered from the sponge symbiotic bacterial Streptomyces reniochalinae LHW50302. Gene deletion and mutant complementation revealed the production of BPDs being correlated with a PKS-NRPS biosynthetic gene cluster (BGC), in which a Dieckmann cyclase gene bpdE was identified by sit-directed mutations. According to bioinformatic analysis, the tetramic acid moiety of BPDs should be formed on an atypical NRPS module constituted by two discrete proteins, including the C (condensation)-A (adenylation)-T (thiolation) domains of BpdC and the A-T domains of BpdD. Further site-directed mutagenetic analysis confirmed the natural silence of the A domain in BpdC and the functional necessities of the two T domains, therefore suggesting that an unusual aminoacyl transthiolation should occur between the T domains of two NRPS subunits. Additionally, characterization of a LuxR type regulator gene led to seven- to eight-fold increasement of BPDs production. The study presents the first biosynthesis case of the natural molecule with 3-(2H-pyran-2-ylidene)pyrrolidine-2,4-dione skeleton. Genomic mining using BpdD as probe reveals that the aminoacyl transthiolation between separate NRPS subunits should occur in a certain population of NRPSs in nature.
Assuntos
Vias Biossintéticas , Policetídeo Sintases , Pirrolidinonas , Policetídeo Sintases/metabolismo , Bactérias/metabolismo , Piranos/metabolismo , Esqueleto/metabolismo , Peptídeo Sintases/genéticaRESUMO
Six new sesquiterpene quinone/hydroquinone meroterpenoids, arenarialins A-F (1-6), were isolated from the marine sponge Dysidea arenaria collected from the South China Sea. Their chemical structures and absolute configurations were determined by HRMS and NMR data analyses coupled with DP4+ and ECD calculations. Arenarialin A (1) features an unprecedented tetracyclic 6/6/5/6 carbon skeleton, whereas arenarialins B-D (2-4) possess two rare secomeroterpene scaffolds. Arenarialins A-F showed inhibitory activity on the production of inflammatory cytokines TNF-α and IL-6 in LPS-induced RAW264.7 macrophages with arenarialin D regulating the NF-κB/MAPK signaling pathway.
Assuntos
Dysidea , Poríferos , Sesquiterpenos , Animais , Dysidea/química , Poríferos/química , Sesquiterpenos/farmacologia , Sesquiterpenos/química , Anti-Inflamatórios/farmacologia , NF-kappa B , Estrutura MolecularRESUMO
Two new cytochalasans, marcytoglobosins A (1) and B (2) were isolated from the marine sponge associated fungus Chaetomium globosum 162105, along with six known compounds (3-8). The complete structures of two new compounds were determined based on 1D/2D NMR and HR-MS spectroscopic analyses coupled with ECD calculations. All eight isolates were evaluated for their antibacterial activity. Among them, compounds 3-8 displayed antibacterial effects against Staphylococcus epidermidis, Bacillus thuringiensis, Pseudomonas syringae pv. Actinidiae, Vibrio alginolyticus, and Edwardsiella piscicida with minimum inhibitory concentration (MIC) values ranging from 10 to 25â µg/mL.
Assuntos
Antibacterianos , Chaetomium , Testes de Sensibilidade Microbiana , Poríferos , Chaetomium/química , Animais , Poríferos/microbiologia , Poríferos/química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Citocalasinas/farmacologia , Citocalasinas/química , Citocalasinas/isolamento & purificação , Conformação MolecularRESUMO
Covering: 2010 to 2021Sesquiterpene quinone/quinols (SQs) are characterized by a C15-sesquiterpenoid unit incorporating a C6-benzoquinone/quinol moiety. Numerous unprecedented carbon skeletons have been constructed with various connection patterns between the two parts. The potent anti-cancer, anti-inflammatory, anti-microbial, anti-viral, and fibrinolytic activities of SQs are associated with their diverse structures. The representative avarol has even entered the stage of clinical phase II research as an anti-HIV agent, and was developed as paramedic medicine against psoriasis. This review provides an overall summary of 558 new natural SQs discovered between 2010 and 2021, including seven groups and sixteen structure-type subgroups, which comprehensively recapitulates their chemical structures, spectral characteristics, source organisms, biological activities, synthesis, and biosynthesis, aiming to expand the application scope of this unique natural product resource.
Assuntos
Hidroquinonas , Sesquiterpenos , Sesquiterpenos/farmacologia , Quinonas/farmacologia , BenzoquinonasRESUMO
Background: Venous thromboembolism (VTE) is a common cardiovascular disease that seriously threatens human lives. Anticoagulant therapy is considered to be the cornerstone of VTE treatment. An increasing number of studies has been updated in the VTE anticoagulation field. However, no bibliometric analyses have assessed these publications comprehensively. Therefore, our study aimed to analyze the global status, hotspots, and trends of anticoagulant therapy for VTE. Methods: The relevant literature on VTE anticoagulation published between 2012 and 2021 was retrieved and collected from the Web of Science Core Collection database. VOSviewer, Cooccurrence Matrix Builder, gCLUTO, and some online visualization tools were adopted for bibliometric analysis. Results: A total of 15,152 related articles were retrieved. In recent years, the research output of VTE anticoagulation gradually increased. The United States was the most productive country. International cooperation is concentrated in North America and Europe; the most influential documents, journals, authors, and organizations were also from these two continents. Research hotspots mainly focus on clinical guidelines, VTE in special populations, non-vitamin K oral anticoagulants (NOACs), and parenteral anticoagulation. The research frontiers and trends include the assessment of NOACs and the antithrombotic management of VTE complicated with coronavirus disease 2019 (COVID-19). Conclusion: This bibliometric analysis provides a systematic overview of the VTE anticoagulation research, which will facilitate researchers to better understand the situation of VTE anticoagulation. Future studies should be dedicated to NOACs application and VTE-combined COVID-19 patients.
Assuntos
COVID-19 , Tromboembolia Venosa , Humanos , Administração Oral , Anticoagulantes/uso terapêutico , COVID-19/complicações , Tromboembolia Venosa/tratamento farmacológico , Tromboembolia Venosa/prevenção & controle , Tromboembolia Venosa/etiologia , Vitamina K/uso terapêutico , BibliometriaRESUMO
BACKGROUND: Direct oral anticoagulants (DOACs) are increasingly recommended over warfarin in stroke prevention for patients with non-valvular atrial fibrillation (AF). However, there is an important evidence gap in choosing the most appropriate DOAC for Chinese patients in clinical practice. METHODS: A multi-criteria decision analysis (MCDA) was adopted to build a scoring framework. Attributes and criteria were identified and determined by a scoping literature review, two rounds of Delphi surveys, and a consensus meeting. Weights of each attribute and criterion in the framework were determined using analytic hierarchy process (AHP). Evidence was collected based on the domestic or at least Asian data. Scoring methods for each criterion were developed depended on their characteristics and determined with an expert consensus meeting. Comprehensive scores of each DOAC were calculated based on the utility scores of each criterion and their corresponding weights. RESULTS: A total of 5 attributes, including safety, efficacy, costs/cost-effectiveness, suitability, and accessibility, were determined, and 16 criteria were under the 5 attributes. The safety and efficacy were ranked as the top two important attributes with the weights of 38.8% and 35.9%, respectively, while the suitability received the lowest weight of 7.9%. The comprehensive score for edoxaban was the highest (72.3), followed by dabigatran (49.7), rivaroxaban (37.9), and apixaban (35.8). CONCLUSIONS: This study provided a scoring framework developed for comprehensive evaluation of DOACs in China. The ranking of DOACs could help to support the decision-making in clinical practice. The framework could provide a reference for comprehensive evaluation of other drugs.
Assuntos
Fibrilação Atrial , Acidente Vascular Cerebral , Humanos , Fibrilação Atrial/complicações , Fibrilação Atrial/tratamento farmacológico , Anticoagulantes/uso terapêutico , Acidente Vascular Cerebral/prevenção & controle , Acidente Vascular Cerebral/tratamento farmacológico , Varfarina/uso terapêutico , Rivaroxabana/uso terapêutico , Dabigatrana/uso terapêutico , Piridonas/uso terapêutico , Administração OralRESUMO
Phyllospongianes A-E (1-5), five new scalarane derivatives featuring an unprecedented 6/6/6/5 tetracyclic dinorscalarane scaffold, along with the known probable biogenetic precursor, 12-deacetylscalaradial (6), were isolated from the marine sponge Phyllospongia foliascens. The structures of the isolated compounds were determined by analysis of spectroscopic data and electronic circular dichroism experiments. Compounds 1-5 are the first 6/6/6/5 tetracyclic scalarane derivatives to be reported within the scalarane family. Compounds 1, 2, and 4 exhibited antibacterial activity against Vibrio vulnificus, Vibrio parahemolyticus, Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, and Pseudomonas aeruginosa with MIC values ranging from 1 to 8 µg/mL. Furthermore, compound 3 exhibited significant cytotoxic activity on MDA-MB-231, HepG2, C4-2-ENZ, MCF-7, H460, and HT-29 cancer cell lines with IC50 values in the range between 0.7 and 13.2 µM.
Assuntos
Antineoplásicos , Poríferos , Animais , Sesterterpenos/química , Poríferos/química , Antineoplásicos/química , Antibacterianos/farmacologia , Bacillus subtilis , Escherichia coli , Estrutura MolecularRESUMO
Burkitt's lymphoma (BL) has a particularly extremely poor prognosis and the fastest growth rate among human tumors, and the development of new drugs for the treatment of BL is urgently needed. In this study, the cytotoxic properties of 3,7-bis(3,5-dimethylphenyl)-aaptamine (AP-51), a new semisynthetic alkaloid derived from the marine natural product aapatamine, were investigated using BL cell lines. Our results showed that AP-51 inhibited the proliferation of Daudi and Raji cells with IC50 values of 3.48 and 2.07 µM, respectively. Flow cytometry and Western blot analyses showed that AP-51 initiated G0/G1 phase arrest by modulating the expression of cyclin-dependent kinases (CDKs). AP-51 also induced apoptosis, as demonstrated by nuclear fragmentation, downregulation of BCL-XL and Mcl-1, and upregulation of cleaved caspase-9, cleaved caspase-3, cleaved-PARP, and cytochrome c, the markers of apoptosis regulated via the mitochondrial pathway. When it comes to mitochondria, AP-51 treatment also significantly increased the levels of intracellular mitochondrial superoxide, decreased ATP content, and reduced the expression of ATP synthase, as well as the expression of the mitochondrial respiratory chain complexes. Finally, AP-51 treatment significantly inhibited the PI3K/AKT/mTOR signaling pathway, which was shown to be associated with the induction of apoptosis. Collectively, these findings indicated that AP-51 initiated cell cycle arrest, induced apoptosis, caused mitochondrial dysfunction, and decreased the phosphorylation of PI3K/AKT/mTOR signaling pathway-related proteins and the protein levels of C-MYC, suggesting that AP-51 has therapeutic potential as a possible treatment for Burkitt's lymphoma.
Assuntos
Alcaloides , Antineoplásicos , Linfoma de Burkitt , Poríferos , Animais , Humanos , Trifosfato de Adenosina , Alcaloides/farmacologia , Alcaloides/uso terapêutico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose , Linfoma de Burkitt/tratamento farmacológico , Linfoma de Burkitt/metabolismo , Linfoma de Burkitt/patologia , Linhagem Celular Tumoral , Proliferação de Células , Mitocôndrias/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Poríferos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismoRESUMO
Cyanogripeptides A-C (1-3), three new cyclolipopeptides with unusual ß-methyl-leucine residues, were identified from an Actinoalloteichus cyanogriseus LHW52806 using an LC-MS-guided strategy. The structures of compounds 1-3 were elucidated by 1D/2D NMR, HR-MS/MS, and the advanced Marfey's method. The absolute configuration of the ß-methyl-leucine residue was determined by a combination of stereoselective biosynthesis of (2S,3R)-ß-methyl-leucine, racemization to its epimer (2R,3R)-ß-methyl-leucine, and the advanced Marfey's method. The biosynthetic pathway of cyanogripeptides was deduced by analyzing the genome of A. cyanogriseus LHW52806. Compound 3 exhibited antibacterial activity against Helicobacter pylori G27, Helicobacter pylori 26695, and Mycolicibacterium smegmatis ATCC607 with MIC values of 32 µg/mL.
Assuntos
Actinobacteria , Actinomycetales , Cromatografia Líquida , Espectrometria de Massas em Tandem , Leucina , Estrutura MolecularRESUMO
A chemical investigation of the marine sponge Phakellia sp. from the South China Sea yielded five new cyclopeptides, phakellisins A-E (1-5). Structures of these compounds were determined by comprehensive analysis of 1D/2D NMR, HRESIMS/MS spectroscopic data and the advanced Marfey's method. All compounds were evaluated for their cytotoxic activity. Compound 1 showed a strong inhibitory activity against WSU-DLCL-2 cells with an IC50 value of 5.25 ± 0.2 µM by induction of G0/G1 cell cycle arrest and apoptosis.
Assuntos
Peptídeos Cíclicos , Poríferos , Animais , Cromatografia Líquida , Peptídeos Cíclicos/farmacologia , Peptídeos Cíclicos/química , Espectrometria de Massas em Tandem , Poríferos/química , Espectroscopia de Ressonância Magnética , Estrutura MolecularRESUMO
Eight new scalarane sesterterpenes, phyllofenones F-M (1-8), together with two known analogues, carteriofenones B and A (9-10), were isolated from the marine sponge Phyllospongia foliascens collected from the South China Sea. The structures of these compounds were determined based on extensive spectroscopic and quantum chemical calculation analysis. The antibacterial and cytotoxic activity of these compounds was evaluated. Among them, only compounds 4 and 6 displayed weak inhibitory activity against Staphylococcus aureus and Escherichia coli, with MIC values of 16 µg/mL and 8 µg/mL, respectively. Compounds 1-10 exhibited cytotoxic activity against the HeLa, HCT-116, H460, and SW1990 cancer cell lines, with IC50 values ranging from 3.4 to 19.8 µM.
Assuntos
Antineoplásicos , Poríferos , Animais , Humanos , Sesterterpenos/química , Poríferos/química , Espectroscopia de Ressonância Magnética , Antineoplásicos/química , Células HeLa , Escherichia coli , Estrutura MolecularRESUMO
Aspergetherins A-D (1-4), four new chlorinated biphenyls, were isolated from the rice fermentation of a marine sponge symbiotic fungus Aspergillus terreus 164018, along with seven known biphenyl derivatives (5-11). The structures of four new compounds were determined by a comprehensive analysis of the spectroscopic data, including HR-ESI-MS and 2D NMR data. All 11 isolates were evaluated for their anti-bacterial activity against two strains of methicillin-resistant Staphylococcus aureus (MRSA). Among them, compounds 1, 3, 8 and 10 showed anti-MRSA activity with MIC values of 1.0-128â µg/mL. Preliminary structure-activity relationship analysis unveiled that both chlorinated substitution and esterification of 2-carboxylic acid could impact the antibacterial activity of biphenyls.
Assuntos
Antibacterianos , Aspergillus , Compostos de Bifenilo , Poríferos , Animais , Antibacterianos/química , Aspergillus/química , Staphylococcus aureus Resistente à Meticilina/metabolismo , Testes de Sensibilidade Microbiana , Estrutura Molecular , Poríferos/microbiologia , Compostos de Bifenilo/química , Compostos de Bifenilo/farmacologiaRESUMO
Four new PKS-NRPS-derived macrolide lactams with three unique ring fusion types were discovered from the Arctic sponge associated actinomycete Streptomyces somaliensis 1107 using a genome mining strategy. Their structures were elucidated by a combination of MS, NMR spectroscopic analysis, and single-crystal X-ray diffraction. Biosynthetically, a novel gene cluster sml consisting of three polyketide synthases and one hybrid polyketide synthase-nonribosomal peptide synthetase together with cytochrome P450s and flavin-containing monooxygenases and oxidoreductases was demonstrated to assemble the unique skeleton. Pharmacological studies revealed that compound 1 displayed a potent anti-inflammatory effect without cytotoxicity. It inhibited IL-6 and TNF-α release in the serum of LPS-stimulated RAW264.7 macrophage cells with IC50 values of 5.76 and 0.18â µM, respectively, and modulated the MAPK pathway. Moreover, compound 1 alleviated LPS-induced systemic inflammation in our transgenic fluorescent zebrafish model.
Assuntos
Lactamas , Macrolídeos , Animais , Macrolídeos/farmacologia , Lactamas/farmacologia , Lipopolissacarídeos/farmacologia , Peixe-Zebra/metabolismo , Antibacterianos , Policetídeo Sintases/metabolismo , Anti-Inflamatórios/farmacologia , Peptídeo Sintases/metabolismo , Família MultigênicaRESUMO
Background: The best anticoagulation choice for patients undergoing transcatheter aortic valve replacement (TAVR) with indications of oral anticoagulation (OAC) remains uncertain. We carried out a comprehensive analysis adopting updated evidence that investigated the efficacy and safety of direct oral anticoagulants (DOACs) versus vitamin K antagonists (VKAs) in this population. Methods: A systematic search has been conducted through PubMed, Embase, and Cochrane Library to collect randomized controlled trials (RCTs) and real-world studies comparing the therapy outcomes of DOACs with VKAs in patients undergoing TAVR with indications of OAC up to Dec 2021. Included studies reported all-cause mortality, bleeding, stroke, or composite endpoint. A random-effects model was used and followed a sensitivity analysis based on the heterogeneity. In addition, five scenario analyses were performed to robust our findings. Results: Our analysis included 11 articles enrolling a total of 8934 patients undergone TAVR with indications of OAC (DOACs group = 3890, VKAs group = 5044). Pooled analysis revealed no significant different risk of all-cause mortality (aHR: 0.95, 95% CI: 0.65-1.39, I 2 : 90.6%), stroke (aHR: 0.86, 95% CI: 0.55-1.35, I 2 : 44.3%), bleeding (aHR: 0.83, 95% CI: 0.61-1.13, I 2 : 76.3%), and composite endpoint (aHR: 1.05, 95% CI: 0.88-1.24, I 2 : 11.7%) in the DOACs and VKAs groups. Various forms of death, stroke and bleeding, including cardiovascular death (aHR: 0.92, 95% CI: 0.64-1.33, I 2 : 34.1%), hemorrhagic stroke (aHR: 0.63, 95% CI: 0.23-1.75, I 2 : 22.7%), ischemic stroke (aHR: 0.79, 95% CI: 0.56-1.15, I 2 : 0.0%), transient ischemic attack (aHR: 0.75, 95% CI: 0.40-1.41, I 2 : 0.0%), major or life-threatening bleeding (aHR: 0.96, 95% CI: 0.74-1.24, I 2 : 27.9%), and minor bleeding (aHR: 0.90, 95% CI: 0.52-1.57, I 2 : 54.3%), also showed similar rates among DOACs and VKAs groups. The results based on five scenarios confirmed the said findings. Conclusions: Compared with VKAs, the efficacy and safety of DOACs were comparable for treating TAVR patients combined with anticoagulation indications. Further large-scale RCTs investigating more detailed scenarios are still needed to confirm the optimal anticoagulation strategy.
RESUMO
A novel actinomycete strain, named LHW52907T, was isolated from a marine sponge (Leucetta chagosensis) collected in the South China Sea. The strain developed branched mycelia without fragmentation and short spore chains in hook-and- spiral form with wrinkled surfaces, bearing no more 10 spores. The cell-wall hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid. The sugars in whole-cell hydrolysates consisted of mannose, ribose, glucose, galactose and madurose. The major fatty acids of the strain were C16â:â0, C17â:â0 and C18â:â1 ω9c. The predominant menaquinone was MK-9(H6). The strain had the highest 16S rRNA gene sequence similarity of 99.72â% to Actinomadura pelletieri DSM 43383T. However, the average nucleotide identity and in silico DNA-DNA hybridization values between them were 93.6 and 52.6â%, respectively, readily distinguishing them as two different species. The results indicate that strain LHW52907T represents a novel species of the genus Actinomadura, for which we propose the name Actinomadura spongiicola sp. nov, with the type strain LHW52907T (=DSM 106571T=CGMCC 4.7596T).
Assuntos
Actinomadura , Poríferos , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos/química , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/químicaRESUMO
PURPOSE: Appropriate prescription of oral anticoagulants (OACs) and good patient adherence are essential to ensure optimal anticoagulation in patients with atrial fibrillation (AF). The aim of this study is to develop a mobile health tool to aid both clinicians and patients with AF in anticoagulation therapy. METHODS: In this study, a novel anticoagulation management model integrating decision support and patient follow-up, the I-Anticoagulation, was developed based on a WeChat Mini Program. With this tool, the risks of stroke and bleeding in AF patients can automatically be calculated according to their characteristics. Anticoagulation regimens were recommended based on a trade-off analysis that balances stroke and bleeding risks according to recent clinical guidelines. A shared decision can be made with full communication between medical professionals and patients. Moreover, follow-up was also conducted using I-Anticoagulation. RESULTS: A total of 120 AF patients receiving anticoagulants (40 received warfarin and 80 received non-vitamin K antagonist oral anticoagulants [NOACs]) were included in the pilot study. The incidence of thromboembolic events was 2.5% and 1.3%, and the rates of bleeding events were 22.5% and 13.8% in the warfarin and NOAC groups, respectively. Generally, self-reported adherence was high, and the satisfaction with anticoagulation was good in all patients with AF. CONCLUSION: Overall, the anticoagulation management model developed in this study could be involved in the full process of anticoagulation therapy in AF patients to improve rationality, adherence, and satisfaction in both medical professionals and patients. However, the usability, feasibility, and acceptability of the I-Anticoagulant-based anticoagulation management model need to be further assessed through well-designed random clinical trials.
Assuntos
Anticoagulantes/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Sistemas de Apoio a Decisões Clínicas/instrumentação , Hemorragia/induzido quimicamente , Acidente Vascular Cerebral/prevenção & controle , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Comunicação , Comorbidade , Estudos de Viabilidade , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Participação do Paciente , Projetos Piloto , Relações Profissional-Paciente , Medição de Risco , TelemedicinaRESUMO
Three new spiro-sesquiterpenoids, myrmekiones A-C (1-3), were isolated from the marine sponge Myrmekioderma sp. collected from the South China Sea. The structures of 1-3 were experimentally illuminated though comprehensive NMR spectra, X-ray diffraction analysis and calculated ECD. These three compounds possessed a special spiro skeleton. Compound 1 was characterized by a chamigrane-type structure, it is the first time to obtain the single-crystal of this type of oil compounds. 2 and 3 were a pair of diastereoisomers that possessed an acorane skeleton. This study expands the chemical diversity of marine origin spiro-metabolites.
Assuntos
Poríferos , Sesquiterpenos , Animais , China , Cristalografia por Raios X , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Poríferos/química , Sesquiterpenos/químicaRESUMO
Mesophotic coral ecosystems (MCEs) represent an underexplored source of intriguing natural products. Efforts to discover bioactive metabolites from sponge-associated fungi in MCEs identified a new steroid, acremocholone (1) and its three known analogs (2-4), from Acremonium sp. NBUF150. The Acremonium sp. NBUF150 was isolated from a Ciocalypta sponge located 70â m deep within the South China Sea. The planar structures and absolute configuration of 1-4 were determined from NMR-derived spectroscopic data, HR-ESI-MS, and X-ray crystallography. Compound 1 exhibited antimicrobial inhibition against Vibrio scophthalmi, V.â shilonii and V.â brasiliensis at minimum inhibitory concentrations of 8 µg/mL; compound 2 inhibited V.â shilonii and V.â brasiliensis at 8 and 32â µg/mL, respectively, and compound 4 inhibited growth of V.â brasiliensis at 16â µg/mL. Sponge associated fungi from MCEs represent a promising resource of anti-Vibrio drug leads for aquaculture use.
Assuntos
Acremonium , Antozoários , Poríferos , Animais , Ecossistema , Fungos , Esteroides/farmacologiaRESUMO
Neoantimycins are anticancer compounds of 15-membered ring antimycin-type depsipeptides. They are biosynthesized by a hybrid multimodular protein complex of nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS), typically from the starting precursor 3-formamidosalicylate. Examining fermentation extracts of Streptomyces conglobatus, here we discovered four new neoantimycin analogs, unantimycins B-E, in which 3-formamidosalicylates are replaced by an unusual 3-hydroxybenzoate (3-HBA) moiety. Unantimycins B-E exhibited levels of anticancer activities similar to those of the chemotherapeutic drug cisplatin in human lung cancer, colorectal cancer, and melanoma cells. Notably, they mostly displayed no significant toxicity toward noncancerous cells, unlike the serious toxicities generally reported for antimycin-type natural products. Using site-directed mutagenesis and heterologous expression, we found that unantimycin productions are correlated with the activity of a chorismatase homolog, the nat-hyg5 gene, from a type I PKS gene cluster. Biochemical analysis confirmed that the catalytic activity of Nat-hyg5 generates 3-HBA from chorismate. Finally, we achieved selective production of unantimycins B and C by engineering a chassis host. On the basis of these findings, we propose that unantimycin biosynthesis is directed by the neoantimycin-producing NRPS-PKS complex and initiated with the starter unit of 3-HBA. The elucidation of the biosynthetic unantimycin pathway reported here paves the way to improve the yield of these compounds for evaluation in oncotherapeutic applications.