RESUMEN
OBJECTIVES: To update the EULAR recommendations for the management of systemic lupus erythematosus (SLE) based on emerging new evidence. METHODS: An international Task Force formed the questions for the systematic literature reviews (January 2018-December 2022), followed by formulation and finalisation of the statements after a series of meetings. A predefined voting process was applied to each overarching principle and recommendation. Levels of evidence and strengths of recommendation were assigned, and participants finally provided their level of agreement with each item. RESULTS: The Task Force agreed on 5 overarching principles and 13 recommendations, concerning the use of hydroxychloroquine (HCQ), glucocorticoids (GC), immunosuppressive drugs (ISDs) (including methotrexate, mycophenolate, azathioprine, cyclophosphamide (CYC)), calcineurin inhibitors (CNIs, cyclosporine, tacrolimus, voclosporin) and biologics (belimumab, anifrolumab, rituximab). Advice is also provided on treatment strategies and targets of therapy, assessment of response, combination and sequential therapies, and tapering of therapy. HCQ is recommended for all patients with lupus at a target dose 5 mg/kg real body weight/day, considering the individual's risk for flares and retinal toxicity. GC are used as 'bridging therapy' during periods of disease activity; for maintenance treatment, they should be minimised to equal or less than 5 mg/day (prednisone equivalent) and, when possible, withdrawn. Prompt initiation of ISDs (methotrexate, azathioprine, mycophenolate) and/or biological agents (anifrolumab, belimumab) should be considered to control the disease and facilitate GC tapering/discontinuation. CYC and rituximab should be considered in organ-threatening and refractory disease, respectively. For active lupus nephritis, GC, mycophenolate or low-dose intravenous CYC are recommended as anchor drugs, and add-on therapy with belimumab or CNIs (voclosporin or tacrolimus) should be considered. Updated specific recommendations are also provided for cutaneous, neuropsychiatric and haematological disease, SLE-associated antiphospholipid syndrome, kidney protection, as well as preventative measures for infections, osteoporosis, cardiovascular disease. CONCLUSION: The updated recommendations provide consensus guidance on the management of SLE, combining evidence and expert opinion.
Asunto(s)
Azatioprina , Lupus Eritematoso Sistémico , Humanos , Azatioprina/uso terapéutico , Tacrolimus/uso terapéutico , Rituximab/uso terapéutico , Metotrexato/uso terapéutico , Lupus Eritematoso Sistémico/complicaciones , Inmunosupresores/uso terapéutico , Ciclofosfamida/uso terapéutico , Hidroxicloroquina/uso terapéutico , Glucocorticoides/uso terapéutico , Inhibidores Enzimáticos/uso terapéuticoRESUMEN
SLE presents significant challenges for patients and health-care professionals (HCPs), both across Europe and worldwide. Improving health-care outcomes for patients with SLE requires a comprehensive understanding of patient disease pathways. In particular, the geographical distance between SLE patients and specialized care centres, combined with the scarcity of rheumatologists, exacerbates delays in diagnosis and management. Also, the initial SLE symptoms can often be non-specific, and providing guidelines for primary HCPs and other non-specialists is extremely important. Improvement in access to treatment is also important, with several recently approved therapies for SLE not being available in several European countries and many low- and middle-income countries (LMICs). Furthermore, in the LMICs in which these treatments are available, they are not always covered by the health-care system, making their access almost impossible for those of lower socio-economic status. A number of provisions are already in place within the European Union, to improve access to care for patients with rare and complex diseases, including those with SLE. In particular, European Reference Networks (ERNs), such the ERN for Autoimmune Diseases ReCONNET, are virtual networks involving HCPs across Europe with the aim of improving the care of patients with rare and complex diseases that require highly specialized treatment and a concentration of knowledge and resources. In addition, lupus patient organizations such as Lupus Europe play a crucial role in raising awareness of SLE and advocating for improved access to care. Together, we can work towards a future where all people living with lupus receive the comprehensive and timely care they deserve.
Asunto(s)
Accesibilidad a los Servicios de Salud , Lupus Eritematoso Sistémico , Humanos , Lupus Eritematoso Sistémico/terapia , Europa (Continente) , Salud GlobalRESUMEN
Recent studies have shown that people who are immunocompromised may inadvertently play a role in spurring the mutations of the virus that create new variants. This is because some immunocompromised individuals remain at risk of getting COVID-19 despite vaccination, experience more severe disease, are susceptible to being chronically infected and remain contagious for longer if they become infected and considering that immunocompromised individuals represent approximately 2% of the overall population, this aspect should be carefully considered. So far, some autoimmune rheumatic disease (ARD) patients with COVID-19 have been treated with antiviral therapies or anti-SARS-CoV-2 antibody products. However, there is no homogeneous approach to these treatment strategies. This issue was addressed within the European Reference Network (ERN) on Rare and Complex Connective Tissue and Musculoskeletal Diseases (ReCONNET) in a discussion among experts and patient's representatives in the context of the rare and complex connective tissue diseases (rCTDs) covered by the Network. ERN ReCONNET is one of the 24 ERNs launched by the European Commission in 2017 with the aim of tackling low prevalence and rare diseases that require highly specialised treatment and promoting concentration of knowledge and resources through virtual networks involving healthcare providers (HCPs) across the European Union (EU). Considering the urgent need to provide guidance not only to the rCTDs community, but also to the whole ARDs community, a multidisciplinary Task Force, including expert clinicians and European Patient Advocacy Group (ePAG) Advocates, was created in the framework of ERN ReCONNET with the aim of developing overarching principles (OP) and points-to-consider (PtC) on a homogenous approach to treat immunocompromised patients with ARDs (with a particular focus on CTDs) affected by COVID-19 using antiviral therapies and anti-SARS-CoV-2 antibody products. The present work reports the final OP and PtC agreed by the Task Force.
Asunto(s)
Enfermedades Autoinmunes , COVID-19 , Síndrome de Dificultad Respiratoria , Enfermedades Reumáticas , Humanos , Enfermedades Autoinmunes/tratamiento farmacológico , Enfermedades Reumáticas/tratamiento farmacológico , Enfermedades Reumáticas/epidemiología , Antivirales/uso terapéuticoRESUMEN
Treatment options for infections caused by antimicrobial-resistant bacteria are rendered ineffective, and drug alternatives are needed-either from new chemical classes or drugs with new modes of action. Historically, natural products have been important contributors to drug discovery. In a recent study, the dimeric naphthopyrone lulworthinone produced by an obligate marine fungus in the family Lulworthiaceae was discovered. The observed potent antibacterial activity against Gram-positive bacteria, including several clinical methicillin-resistant Staphylococcus aureus (MRSA) isolates, prompted this follow-up mode of action investigation. This paper aimed to characterize the antibacterial mode of action (MOA) of lulworthinone by combining in vitro assays, NMR experiments and microscopy. The results point to a MOA targeting the bacterial membrane, leading to improper cell division. Treatment with lulworthinone induced an upregulation of genes responding to cell envelope stress in Bacillus subtilis. Analysis of the membrane integrity and membrane potential indicated that lulworthinone targets the bacterial membrane without destroying it. This was supported by NMR experiments using artificial lipid bilayers. Fluorescence microscopy revealed that lulworthinone affects cell morphology and impedes the localization of the cell division protein FtsZ. Surface plasmon resonance and dynamic light scattering assays showed that this activity is linked with the compound's ability to form colloidal aggregates. Antibacterial agents acting at cell membranes are of special interest, as the development of bacterial resistance to such compounds is deemed more difficult to occur.
Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Antibacterianos/química , Bacterias , Hongos , Bacterias Grampositivas , Pruebas de Sensibilidad Microbiana , Polímeros/farmacologíaRESUMEN
Bacterial symbionts of marine invertebrates are rich sources of novel, pharmaceutically relevant natural products that could become leads in combatting multidrug-resistant pathogens and treating disease. In this study, the bioactive potential of the marine invertebrate symbiont Thalassomonas actiniarum was investigated. Bioactivity screening of the strain revealed Gram-positive specific antibacterial activity as well as cytotoxic activity against a human melanoma cell line (A2058). The dereplication of the active fraction using HPLC-MS led to the isolation and structural elucidation of cholic acid and 3-oxo cholic acid. T. actiniarum is one of three type species belonging to the genus Thalassomonas. The ability to generate cholic acid was assessed for all three species using thin-layer chromatography and was confirmed by LC-MS. The re-sequencing of all three Thalassomonas type species using long-read Oxford Nanopore Technology (ONT) and Illumina data produced complete genomes, enabling the bioinformatic assessment of the ability of the strains to produce cholic acid. Although a complete biosynthetic pathway for cholic acid synthesis in this genus could not be determined based on sequence-based homology searches, the identification of putative penicillin or homoserine lactone acylases in all three species suggests a mechanism for the hydrolysis of conjugated bile acids present in the growth medium, resulting in the generation of cholic acid and 3-oxo cholic acid. With little known currently about the bioactivities of this genus, this study serves as the foundation for future investigations into their bioactive potential as well as the potential ecological role of bile acid transformation, sterol modification and quorum quenching by Thalassomonas sp. in the marine environment.
Asunto(s)
Antibacterianos , Humanos , Ácido Cólico , Filogenia , ADN Bacteriano , Antibacterianos/farmacología , Análisis de Secuencia de ADNRESUMEN
"One strain many compounds" (OSMAC) based approaches have been widely used in the search for bioactive compounds. Introducing stress factors like nutrient limitation, UV-light or cocultivation with competing organisms has successfully been used in prokaryote cultivation. It is known that diatom physiology is affected by changed cultivation conditions such as temperature, nutrient concentration and light conditions. Cocultivation, though, is less explored. Hence, we wanted to investigate whether grazing pressure can affect the metabolome of the marine diatom Porosira glacialis, and if the stress reaction could be detected as changes in bioactivity. P. glacialis cultures were mass cultivated in large volume bioreactor (6000 L), first as a monoculture and then as a coculture with live zooplankton. Extracts of the diatom biomass were screened in a selection of bioactivity assays: inhibition of biofilm formation, antibacterial and cell viability assay on human cells. Bioactivity was found in all bioassays performed. The viability assay towards normal lung fibroblasts revealed that P. glacialis had higher bioactivity when cocultivated with zooplankton than in monoculture. Cocultivation with diatoms had no noticeable effect on the activity against biofilm formation or bacterial growth. The metabolic profiles were analyzed showing the differences in diatom metabolomes between the two culture conditions. The experiment demonstrates that grazing stress affects the biochemistry of P. glacialis and thus represents a potential tool in the OSMAC toolkit.
Asunto(s)
Biomasa , Diatomeas/metabolismo , Zooplancton/metabolismo , Animales , Biopelículas/crecimiento & desarrollo , Supervivencia Celular/fisiología , Diatomeas/aislamiento & purificación , Células HT29 , Humanos , Metaboloma/fisiología , Zooplancton/aislamiento & purificaciónRESUMEN
The marine environment is potentially a prolific source of small molecules with significant biological activities. In recent years, the development of new chromatographic phases and the progress in cell and molecular techniques have facilitated the search for marine natural products (MNPs) as novel pharmacophores and enhanced the success rate in the selection of new potential drug candidates. However, most of this exploration has so far been driven by anticancer research and has been limited to a reduced number of taxonomic groups. In this article, we report a test study on the screening potential of an in-house library of natural small molecules composed of 285 samples derived from 57 marine organisms that were chosen from among the major eukaryotic phyla so far represented in studies on bioactive MNPs. Both the extracts and SPE fractions of these organisms were simultaneously submitted to three different bioassays-two phenotypic and one enzymatic-for cytotoxic, antidiabetic, and antibacterial activity. On the whole, the screening of the MNP library selected 11 potential hits, but the distribution of the biological results showed that SPE fractionation increased the positive score regardless of the taxonomic group. In many cases, activity could be detected only in the enriched fractions after the elimination of the bulky effect due to salts. On a statistical basis, sponges and molluscs were confirmed to be the most significant source of cytotoxic and antimicrobial products, but other phyla were found to be effective with the other therapeutic targets.
Asunto(s)
Antineoplásicos/farmacología , Organismos Acuáticos , Animales , Antineoplásicos/química , Fraccionamiento Químico , Descubrimiento de Drogas , Moluscos , PoríferosRESUMEN
As part of our search for bioactive metabolites from understudied marine microorganisms, the new chlorinated metabolite chlovalicin B (1) was isolated from liquid cultures of the marine basidiomycete Digitatispora marina, which was collected and isolated from driftwood found at Vannøya, Norway. The structure of the novel compound was elucidated by spectroscopic methods including 1D and 2D NMR and analysis of HRMS data, revealing that 1 shares its molecular scaffold with a previously isolated compound, chlovalicin. This represents the first compound isolated from the Digitatispora genus, and the first reported fumagillin/ovalicin-like compound isolated from Basidiomycota. Compound 1 was evaluated for antibacterial activities against a panel of five bacteria, its ability to inhibit bacterial biofilm formation, for antifungal activity against Candida albicans, and for cytotoxic activities against malignant and non-malignant human cell lines. Compound 1 displayed weak cytotoxic activity against the human melanoma cell line A2058 (~50% survival at 50 µM). No activity was detected against biofilm formation or C. albicans at 50 µM, or against bacterial growth at 100 µM nor against the production of cytokines by the human acute monocytic leukemia cell line THP-1 at 50 µM.
Asunto(s)
Antibacterianos , Antifúngicos , Bacterias/crecimiento & desarrollo , Basidiomycota/química , Candida albicans/crecimiento & desarrollo , Sesquiterpenos , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Antifúngicos/química , Antifúngicos/aislamiento & purificación , Antifúngicos/farmacología , Ciclohexanonas/química , Ciclohexanonas/aislamiento & purificación , Ciclohexanonas/farmacología , Compuestos Epoxi/química , Compuestos Epoxi/aislamiento & purificación , Compuestos Epoxi/farmacología , Sesquiterpenos/química , Sesquiterpenos/aislamiento & purificación , Sesquiterpenos/farmacologíaRESUMEN
The Lacinutrix genus was discovered in 2005 and includes 12 Gram-negative bacterial species. To the best of our knowledge, the secondary metabolite production potential of this genus has not been explored before, and examination of Lacinutrix species may reveal novel chemistry. As part of a screening project of Arctic marine bacteria, the Lacinutrix sp. strain M09B143 was cultivated, extracted, fractionated and tested for antibacterial and cytotoxic activities. One fraction had antibacterial activity and was subjected to mass spectrometry analysis, which revealed two compounds with elemental composition that did not match any known compounds in databases. This resulted in the identification and isolation of two novel isobranched lyso-ornithine lipids, whose structures were elucidated by mass spectrometry and NMR spectroscopy. Lyso-ornithine lipids consist of a 3-hydroxy fatty acid linked to the alpha amino group of an ornithine amino acid through an amide bond. The fatty acid chains were determined to be iso-C15:0 (1) and iso-C16:0 (2). Compound 1 was active against the Gram-positive S. agalactiae, while 2 showed cytotoxic activity against A2058 human melanoma cells.
Asunto(s)
Flavobacteriaceae/metabolismo , Lípidos/química , Ornitina/química , Regiones Árticas , Espectroscopía de Resonancia MagnéticaRESUMEN
A series of novel quinoline-based tetracyclic ring-systems were synthesized and evaluated in vitro for their antiplasmodial, antiproliferative and antimicrobial activities. The novel hydroiodide salts 10 and 21 showed the most promising antiplasmodial inhibition, with compound 10 displaying higher selectivity than the employed standards. The antiproliferative assay revealed novel pyridophenanthridine 4b to be significantly more active against human prostate cancer (IC50 = 24 nM) than Puromycin (IC50 = 270 nM) and Doxorubicin (IC50 = 830 nM), which are used for clinical treatment. Pyridocarbazoles 9 was also moderately effective against all the employed cancer cell lines and moreover showed excellent biofilm inhibition (9a: MBIC = 100 µM; 9b: MBIC = 100 µM).
Asunto(s)
Alcaloides Indólicos/farmacología , Quinolinas/síntesis química , Quinolinas/farmacología , Antiinfecciosos/farmacología , Antimaláricos/farmacología , Antineoplásicos/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos , Alcaloides Indólicos/metabolismo , Plasmodium falciparum/efectos de los fármacos , Quinolinas/metabolismo , Relación Estructura-ActividadRESUMEN
Dehydroalanine (Dha) and dehydrobutyrine (Dhb) display considerable flexibility in a variety of chemical and biological reactions. Natural products containing Dha and/or Dhb residues are often found to display diverse biological activities. While the (Z) geometry is predominant in nature, only a handful of metabolites containing (E)-Dhb have been found thus far. Here we report discovery of a new antimicrobial peptide, albopeptide, through NMR analysis and chemical synthesis, which contains two contiguous unsaturated residues, Dha-(E)-Dhb. It displays narrow-spectrum activity against vancomycin-resistant Enterococcusâ faecium. In-vitro biochemical assays show that albopeptide originates from a noncanonical NRPS pathway featuring dehydration processes and catalysed by unusual condensation domains. Finally, we provide evidence of the occurrence of a previously untapped group of short unsaturated peptides in the bacterial kingdom, suggesting an important biological function in bacteria.
Asunto(s)
Antibacterianos/biosíntesis , Péptidos Catiónicos Antimicrobianos/química , Alanina/análogos & derivados , Alanina/química , Aminobutiratos/química , Antibacterianos/química , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/biosíntesis , Péptidos Catiónicos Antimicrobianos/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Evaluación Preclínica de Medicamentos , Farmacorresistencia Bacteriana/efectos de los fármacos , Enterococcus faecium/efectos de los fármacos , Familia de Multigenes , Resonancia Magnética Nuclear Biomolecular , Biosíntesis de Péptidos Independientes de Ácidos Nucleicos , Péptido Sintasas/genética , Péptido Sintasas/metabolismo , Estereoisomerismo , Streptomyces/enzimología , Streptomyces/metabolismoRESUMEN
Microalgae have been shown to be excellent producers of lipids, pigments, carbohydrates, and a plethora of secondary metabolites with possible applications in the pharmacological, nutraceutical, and cosmeceutical sectors. Recently, various microalgal raw extracts have been found to have anti-inflammatory properties. In this study, we performed the fractionation of raw extracts of the diatom Cylindrotheca closterium, previously shown to have anti-inflammatory properties, obtaining five fractions. Fractions C and D were found to significantly inhibit tumor necrosis factor alpha (TNF-âº) release in LPS-stimulated human monocyte THP-1 cells. A dereplication analysis of these two fractions allowed the identification of their main components. Our data suggest that lysophosphatidylcholines and a breakdown product of chlorophyll, pheophorbide a, were probably responsible for the observed anti-inflammatory activity. Pheophorbide a is known to have anti-inflammatory properties. We tested and confirmed the anti-inflammatory activity of 1-palmitoyl-sn-glycero-3-phosphocholine, the most abundant lysophosphatidylcholine found in fraction C. This study demonstrated the importance of proper dereplication of bioactive extracts and fractions before isolation of compounds is commenced.
Asunto(s)
Antiinflamatorios/farmacología , Clorofila/farmacología , Diatomeas , Lisofosfatidilcolinas/farmacología , Factor de Necrosis Tumoral alfa/efectos de los fármacos , Antiinflamatorios/química , Clorofila/química , Humanos , Lisofosfatidilcolinas/química , Océanos y Mares , Células THP-1/efectos de los fármacos , Células THP-1/metabolismoRESUMEN
Turgencin A, a potent antimicrobial peptide isolated from the Arctic sea squirt Synoicum turgens, consists of 36 amino acid residues and three disulfide bridges, making it challenging to synthesize. The aim of the present study was to develop a truncated peptide with an antimicrobial drug lead potential based on turgencin A. The experiments consisted of: (1) sequence analysis and prediction of antimicrobial potential of truncated 10-mer sequences; (2) synthesis and antimicrobial screening of a lead peptide devoid of the cysteine residues; (3) optimization of in vitro antimicrobial activity of the lead peptide using an amino acid replacement strategy; and (4) screening the synthesized peptides for cytotoxic activities. In silico analysis of turgencin A using various prediction software indicated an internal, cationic 10-mer sequence to be putatively antimicrobial. The synthesized truncated lead peptide displayed weak antimicrobial activity. However, by following a systematic amino acid replacement strategy, a modified peptide was developed that retained the potency of the original peptide. The optimized peptide StAMP-9 displayed bactericidal activity, with minimal inhibitory concentrations of 7.8 µg/mL against Staphylococcus aureus and 3.9 µg/mL against Escherichia coli, and no cytotoxic effects against mammalian cells. Preliminary experiments indicate the bacterial membranes as immediate and primary targets.
Asunto(s)
Péptidos Catiónicos Antimicrobianos/farmacología , Productos Biológicos/química , Proteínas Citotóxicas Formadoras de Poros/farmacología , Secuencia de Aminoácidos/genética , Animales , Péptidos Catiónicos Antimicrobianos/síntesis química , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/genética , Organismos Acuáticos/genética , Productos Biológicos/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/patogenicidad , Humanos , Pruebas de Sensibilidad Microbiana , Proteínas Citotóxicas Formadoras de Poros/síntesis química , Proteínas Citotóxicas Formadoras de Poros/química , Proteínas Citotóxicas Formadoras de Poros/genética , Análisis de Secuencia de Proteína , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/patogenicidadRESUMEN
Streptomyces remains one of the prolific sources of structural diversity, and a reservoir to mine for novel natural products. Continued screening for new Streptomyces strains in our laboratory led to the isolation of Streptomyces sp. RK44 from the underexplored areas of Kintampo waterfalls, Ghana, Africa. Preliminary screening of the metabolites from this strain resulted in the characterization of a new 2-alkyl-4-hydroxymethylfuran carboxamide (AHFA) 1 together with five known compounds, cyclo-(L-Pro-Gly) 2, cyclo-(L-Pro-L-Phe) 3, cyclo-(L-Pro-L-Val) 4, cyclo-(L-Leu-Hyp) 5, and deferoxamine E 6. AHFA 1, a methylenomycin (MMF) homolog, exhibited anti-proliferative activity (EC50 = 89.6 µM) against melanoma A2058 cell lines. This activity, albeit weak is the first report amongst MMFs. Furthermore, the putative biosynthetic gene cluster (ahfa) was identified for the biosynthesis of AHFA 1. DFO-E 6 displayed potent anti-plasmodial activity (IC50 = 1.08µM) against P. falciparum 3D7. High-resolution electrospray ionization mass spectrometry (HR ESIMS) and molecular network assisted the targeted-isolation process, and tentatively identified six AHFA analogues, 7-12 and six siderophores 13-18.
Asunto(s)
Streptomyces/metabolismo , Antimaláricos/efectos adversos , Antineoplásicos/efectos adversos , Línea Celular Tumoral , Humanos , Familia de Multigenes/genética , Péptidos/efectos adversos , Péptidos/metabolismo , Transducción de Señal/efectos de los fármacos , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
The marine environment remains a rich source for the discovery and development of novel bioactive compounds. The present paper describes the design, synthesis and biological evaluation of a library of small molecule heterocyclic mimetics of the marine 2,5-diketopiperazine barettin which is a powerful natural antioxidant. By mainly focusing on the influence from the brominated indole and heterocyclic core of barettin, a library of 19 compounds was prepared. The compounds comprised a heterocyclic core, either a 2,5 diketopiperazine, an imidazolidinedione or a thioxothiazolidinone, which were mainly monosubstituted with ranging bulky substituents. The prepared compounds were screened for activity in a cellular lipid peroxidation assay using HepG2 cells. Several of the synthetic compounds showed antioxidant properties superior to the positive control barettin. Two of the prepared compounds displayed inhibitory activity similar to commercial antioxidants with significant inhibition at low µg/mL concentrations. The toxicity of the compounds was also investigated against MRC-5 lung fibroblasts and none of the included compounds displayed any toxicity at 50⯵g/mL.
Asunto(s)
Antioxidantes/farmacología , Compuestos Heterocíclicos/farmacología , Peroxidación de Lípido/efectos de los fármacos , Péptidos Cíclicos/química , Bibliotecas de Moléculas Pequeñas/farmacología , Antioxidantes/química , Antioxidantes/aislamiento & purificación , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Fibroblastos/efectos de los fármacos , Células Hep G2 , Compuestos Heterocíclicos/química , Compuestos Heterocíclicos/aislamiento & purificación , Humanos , Estructura Molecular , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/aislamiento & purificación , Relación Estructura-ActividadRESUMEN
Two bacterial isolates from the Barents Sea, both belonging to the genus Algibacter, were found to yield extracts with anti-bacterial bioactivity. Mass spectrometry guided dereplication and purification of the active extracts lead to the isolation of the same active principle in both extracts. The structure of the bioactive compound was identified via mass spectrometry and nuclear resonance spectroscopy and it turned out to be the known lipopeptide Lipid 430. We discovered and determined its previously unknown anti-bacterial activity against Streptococcus agalactiae and revealed a cytotoxic effect against the A2058 human melanoma cell line at significantly lower concentrations compared to its anti-bacterial concentration. Flow cytometry and microscopy investigations of the cytotoxicity against the melanoma cell line indicated that Lipid 430 did not cause immediate cell lysis. The experiments with melanoma cells suggest that the compound functions trough more complex pathways than acting as a simple detergent.
Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Citotoxinas/química , Citotoxinas/farmacología , Flavobacteriaceae/química , Lípidos/química , Lípidos/farmacología , Línea Celular Tumoral , Células HT29 , Humanos , Espectroscopía de Resonancia Magnética/métodos , Espectrometría de Masas/métodos , Melanoma/tratamiento farmacológico , Streptococcus agalactiae/efectos de los fármacosRESUMEN
The marine environment is a rich source of biodiversity, including microorganisms that have proven to be prolific producers of bioactive secondary metabolites. Arctic seas are less explored than warmer, more accessible areas, providing a promising starting point to search for novel bioactive compounds. In the present work, an Arctic marine Pseudomonas sp. belonging to the Pseudomonas (P.) fluorescence group was cultivated in four different media in an attempt to activate biosynthetic pathways leading to the production of antibacterial and anticancer compounds. Culture extracts were pre-fractionated and screened for antibacterial and anticancer activities. One fraction from three of the four growth conditions showed inhibitory activity towards bacteria and cancer cells. The active fractions were dereplicated using molecular networking based on MS/MS fragmentation data, indicating the presence of a cluster of related rhamnolipids. Six compounds were isolated using HPLC and mass-guided fractionation, and by interpreting data from NMR and high-resolution MS/MS analysis; the structures of the compounds were determined to be five mono-rhamnolipids and the lipid moiety of one of the rhamnolipids. Molecular networking proved to be a valuable tool for dereplication of these related compounds, and for the first time, five mono-rhamnolipids from a bacterium within the P. fluorescence group were characterized, including one new mono-rhamnolipid.
Asunto(s)
Antibacterianos/farmacología , Antineoplásicos/farmacología , Organismos Acuáticos/metabolismo , Decanoatos/farmacología , Pseudomonas/metabolismo , Ramnosa/análogos & derivados , Antibacterianos/biosíntesis , Antibacterianos/aislamiento & purificación , Antineoplásicos/aislamiento & purificación , Antineoplásicos/metabolismo , Regiones Árticas , Vías Biosintéticas , Fraccionamiento Químico , Decanoatos/aislamiento & purificación , Ensayos de Selección de Medicamentos Antitumorales , Pruebas de Sensibilidad Microbiana , Ramnosa/biosíntesis , Ramnosa/aislamiento & purificación , Ramnosa/farmacologíaRESUMEN
A new ecdysteroid, ponasterone F (1) and the previously reported compound ponasterone A (2) were isolated from specimens of the Arctic marine bryozoan Alcyonidium gelatinosum collected at Hopenbanken, off the coast of Edgeøya, Svalbard. The structure of 1 was elucidated, and the structure of 2 confirmed by spectroscopic methods including 1D and 2D NMR and analysis of HR-MS data. The compounds were evaluated for their ability to affect bacterial survival and cell viability, as well as their agonistic activities towards the estrogen receptors α and ß. The compounds were not active in these assays. Compound 2 is an arthropod hormone controlling molting and are known to act as an allelochemical when produced by plants. Even though its structure has been previously reported, this is the first time a ponasterone has been isolated from a bryozoan. A. gelatinosum produced 1 and 2 in concentrations surpassing those expected of hormonal molecules, indicating their function as defence molecules against molting predators. This work adds to the chemical diversity reported from marine bryozoans and expanded our knowledge of the chemical modifications of the ponasterones.
Asunto(s)
Antibacterianos , Organismos Acuáticos/química , Bacterias/crecimiento & desarrollo , Briozoos/química , Ecdisterona/análogos & derivados , Animales , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Regiones Árticas , Ecdisterona/química , Ecdisterona/aislamiento & purificación , Ecdisterona/farmacología , Estructura Molecular , Resonancia Magnética Nuclear BiomolecularRESUMEN
A library of 28 small cationic 1,4-substituted 1,2,3-triazoles was prepared for studies of antimicrobial activity. The structures addressed the pharmacophore model of small antimicrobial peptides and an amphipathic motif found in marine antimicrobials. Eight compounds showed promising antimicrobial activity, of which the most potent compound 10b displayed minimum inhibitory concentrations of 4-8µg/mL against Streptococcus agalacticae, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus faecalis. The simple syntheses and low degree of functionalization make these 1,4-substituted 1,2,3-triazoles interesting for further optimizations.
Asunto(s)
Antibacterianos/síntesis química , Antibacterianos/farmacología , Triazoles/síntesis química , Triazoles/farmacología , Antibacterianos/química , Cationes , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Peso Molecular , Triazoles/químicaRESUMEN
A library of 29 small 1,4-substituted 1,2,3-triazoles was prepared for studies of antimicrobial activity. The pharmacophore model investigated with these substrates was based on small peptidomimetics of antimicrobial peptides and antimicrobials isolated from marine organisms from sub-arctic regions. Using methyl 1,2,3-triazole-carboxylates and 1,2,3-triazole methyl ketones prepared through "click" chemistry we were able to synthesize the different cationic amphiphiles through three steps or less. Several structural modifications to the lipopohilic side and hydrophilic sides of the amphiphiles were investigated and compared with regards to antimicrobial activity and cytotoxicity in particular. The most promising amphiphile 10f displayed minimum inhibitory concentrations (MICs) between 4-16µg/mL against Gram-positive Enterococcus faecalis, Staphylococcus aureus, Streptococcus agalacticae, and Gram-negative Escherichia coli and Pseudomonas aeruginosa. The decent level of antimicrobial activity and biofilm inhibition, short synthesis, and accessible reagents, makes this type of amphiphilic mimics interesting leads for further development.