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1.
J Chem Phys ; 158(9): 094201, 2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36889980

RESUMO

We present the first experimental application of coherent Raman spectroscopy (CRS) on the ro-vibrational ν2 mode spectrum of methane (CH4). Ultrabroadband femtosecond/picosecond (fs/ps) CRS is performed in the molecular fingerprint region from 1100 to 2000 cm-1, employing fs laser-induced filamentation as the supercontinuum generation mechanism to provide the ultrabroadband excitation pulses. We introduce a time-domain model of the CH4 ν2 CRS spectrum, including all five ro-vibrational branches allowed by the selection rules Δv = 1, ΔJ = 0, ±1, ±2; the model includes collisional linewidths, computed according to a modified exponential gap scaling law and validated experimentally. The use of ultrabroadband CRS for in situ monitoring of the CH4 chemistry is demonstrated in a laboratory CH4/air diffusion flame: CRS measurements in the fingerprint region, performed across the laminar flame front, allow the simultaneous detection of molecular oxygen (O2), carbon dioxide (CO2), and molecular hydrogen (H2), along with CH4. Fundamental physicochemical processes, such as H2 production via CH4 pyrolysis, are observed through the Raman spectra of these chemical species. In addition, we demonstrate ro-vibrational CH4 v2 CRS thermometry, and we validate it against CO2 CRS measurements. The present technique offers an interesting diagnostics approach to in situ measurement of CH4-rich environments, e.g., in plasma reactors for CH4 pyrolysis and H2 production.

2.
Phytochem Anal ; 34(1): 48-55, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36191930

RESUMO

INTRODUCTION: Data Fusion-based Discovery (DAFdiscovery) is a pipeline designed to help users combine mass spectrometry (MS), nuclear magnetic resonance (NMR), and bioactivity data in a notebook-based application to accelerate annotation and discovery of bioactive compounds. It applies Statistical Total Correlation Spectroscopy (STOCSY) and Statistical HeteroSpectroscopy (SHY) calculation in their data using an easy-to-follow Jupyter Notebook. METHOD: Different case studies are presented for benchmarking, and the resultant outputs are shown to aid natural products identification and discovery. The goal is to encourage users to acquire MS and NMR data from their samples (in replicated samples and fractions when available) and to explore their variance to highlight MS features, NMR peaks, and bioactivity that might be correlated to accelerated bioactive compound discovery or for annotation-identification studies. RESULTS: Different applications were demonstrated using data from different research groups, and it was shown that DAFdiscovery reproduced their findings using a more straightforward method. CONCLUSION: DAFdiscovery has proven to be a simple-to-use method for different situations where data from different sources are required to be analyzed together.


Assuntos
Produtos Biológicos , Espectroscopia de Ressonância Magnética/métodos , Espectrometria de Massas/métodos
3.
Opt Express ; 30(20): 35232-35245, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36258479

RESUMO

Time-resolved spectroscopy can provide valuable insights in hydrogen chemistry, with applications ranging from fundamental physics to the use of hydrogen as a commercial fuel. This work represents the first-ever demonstration of in-situ femtosecond laser-induced filamentation to generate a compressed supercontinuum behind a thick optical window, and its in-situ use to perform femtosecond/picosecond coherent Raman spectroscopy (CRS) on molecular hydrogen (H2). The ultrabroadband coherent excitation of Raman active molecules in measurement scenarios within an enclosed space has been hindered thus far by the window material imparting temporal stretch to the pulse. We overcome this challenge and present the simultaneous single-shot detection of the rotational H2 and the non-resonant CRS spectra in a laminar H2/air diffusion flame. Implementing an in-situ referencing protocol, the non-resonant spectrum measures the spectral phase of the supercontinuum pulse and maps the efficiency of the ultrabroadband coherent excitation achieved behind the window. This approach provides a straightforward path for the implementation of ultrabroadband H2 CRS in enclosed environment such as next-generation hydrogen combustors and reforming reactors.

4.
Rev. colomb. quím. (Bogotá) ; 51(1): 24-39, Jan.-Apr. 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1408079

RESUMO

Abstract Marine Natural Products (MNPs) isolated from samples collected in Colombia have been an object of study since the early 1980's; however, this information is neither integrated nor compiled. This systematic review describes the articles published in scientific journals up to December 2019. 173 papers met the inclusion criteria of focusing on MNPs obtained from specimens collected from Colombian seas; all original papers written in English, Portuguese or Spanish. The selected papers were mostly authored by researchers from Colombian groups, with low interaction amongst themselves. 99.4% of the papers studied samples collected from the Caribbean Sea; 183 species were studied, mainly sponges and octocorals. In this study, 1,690 compounds (238 new ones) were reviewed, mainly diterpenes and sterol derivatives. Of the selected papers, 76.8% measured various biological activities, including antibiotic (34%) and anticancer (30%). These papers were published in 51 journals (74.6% were international). In conclusion, scientific work on natural marine products of Colombian origin has incremented over time. The most relevant opportunities to address and fill existing gaps comprise: exploring Pacific Ocean organisms and several of the misrepresented taxa; promoting strong interactions amongst the MNPs research groups, and accordingly with other areas of knowledge; and having the productive sector participate in MNPs research.


Resumen Los productos naturales marinos (PNM) aislados de muestras recolectadas en Colombia han sido estudiados desde principios de los años 1980, mas esta información no está integrada, ni recopilada. Esta revisión sistemática describe los artículos publicados hasta diciembre de 2019. 173 artículos cumplieron los criterios de inclusión de enfoque en PNM obtenidos de especímenes recolectados en mares colombianos; trabajos originales escritos en inglés, portugués o español. La mayoría de los artículos fueron escritos por investigadores de grupos colombianos, con poca interacción entre ellos. El 99,4% de los artículos estudiaban muestras recolectadas del mar Caribe. Se estudiaron 183 especies, especialmente esponjas y octocorales. Se identificaron 1690 compuestos (238 nuevos), principalmente diterpenos y derivados de esteroles. En el 76,8% de los artículos se midió alguna actividad biológica, principalmente antibiótica (34%) y anticancerígena (30%). Los artículos se publicaron en 51 revistas (74,6% internacionales). En conclusión, la investigación sobre los PNM de origen colombiano ha crecido con el tiempo. Algunas oportunidades para abordar las lagunas encontradas comprenden: explorar los organismos del océano Pacífico y los taxa poco estudiados; promover interacciones entre los grupos de investigación de los PNM y de otras áreas del conocimiento; e involucrar al sector productivo en la investigación de los PMN.


Resumo Os Produtos Naturais Marinhos (PNMs) isolados de amostras coletadas na Colômbia têm sido objeto de estudo desde a década de 1980; porém, esta informação não está integrada nem compilada. Esta revisão sistemática descreve os artigos publicados em revistas científicas até dezembro de 2019. 173 artigos atenderam aos critérios de inclusão de foco em PNMs obtidos de espécimes coletados em mares colombianos; artigos originais escritos em inglês, português ou espanhol. A maioria dos autores dos artigos eram pesquisadores de grupos colombianos, com baixa interação entre eles. 99,4% dos artigos estudavam amostras coletadas no Mar do Caribe. Foram estudadas 183 espécies, especialmente esponjas e octocorais. Nesta revisão, identificaram-se 1690 compostos (238 novos), principalmente diterpenos e derivados de esterol. 76,8% dos artigos mediram algumas atividades biológicas, incluindo antibiótica (34%) e anticancerígena (30%). Os artigos analisados foram publicados em 51 periódicos (74,6% internacionais). Em conclusão, o trabalho científico sobre PNM de origem colombiana cresceu ao longo do tempo. As oportunidades mais relevantes para preencher as lacunas existentes incluem: explorar organismos do Oceano Pacífico e os taxa pouco estudados; promover interação entre os grupos de pesquisa de PNMs e com grupos de outras áreas do conhecimento; e envolver o setor produtivo na pesquisa de PNMs.

5.
Opt Lett ; 47(23): 6105-6108, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37219183

RESUMO

We report on the generation of coherent emission from femtosecond (fs) laser-induced filaments mediated by ultrabroadband coherent Raman scattering (CRS), and we investigate its application for high-resolution gas-phase thermometry. Broadband 35-fs, 800-nm pump pulses generate the filament through photoionization of the N2 molecules, while narrowband picosecond (ps) pulses at 400 nm seed the fluorescent plasma medium via generation of an ultrabroadband CRS signal, resulting in a narrowband and highly spatiotemporally coherent emission at 428 nm. This emission satisfies the phase-matching for the crossed pump-probe beams geometry, and its polarization follows the CRS signal polarization. We perform spectroscopy on the coherent N2 + signal to investigate the rotational energy distribution of the N2 + ions in the excited B2Σu + electronic state and demonstrate that the ionization mechanism of the N2 molecules preserves the original Boltzmann distribution to within the experimental conditions tested.

6.
J Pharm Pharmacol ; 73(11): 1530-1538, 2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34436599

RESUMO

OBJECTIVES: The objective of this work was to evaluate the anti-inflammatory activity of the aqueous extract, fractions and major compounds, which are isolated and identified from Passiflora edulis f. edulis (purple passion fruit) leaves extract. METHODS: For the isolation of the major compounds, reversed-phase chromatography and normal phase countercurrent chromatography were used. The separation was followed by thin layer chromatography and HPLC-DAD-ELSD. One-dimensional and two-dimensional NMR and ESI-TOF-MS/MS were used for structural elucidation. The anti-inflammatory activity was evaluated on a TPA multiple dose model of skin chronic inflammation in mice. Additionally, myeloperoxidase (MPO) and nitric oxide synthase (NOS) activity assays were performed as possible mechanisms of action studies. KEY FINDINGS AND CONCLUSIONS: The study of the butanolic fraction mainly showed the presence of saponins and flavonoids. Three minor flavonoids were detected; and three known saponins, cyclopassiflosides IX, XI and III were isolated and identified. This is the first unequivocal report of the presence of these compounds in P. edulis f. edulis leaves. The most favourable results of anti-inflammatory activity were obtained for the flavonoid-rich fraction. All the fractions and isolated compounds evaluated, presented high percentages of inhibition of nitric oxide synthase activity.


Assuntos
Anti-Inflamatórios/uso terapêutico , Flavonoides/uso terapêutico , Inflamação/prevenção & controle , Passiflora/química , Fitoterapia , Saponinas/uso terapêutico , Pele/efeitos dos fármacos , Animais , Anti-Inflamatórios/farmacologia , Cromatografia Líquida de Alta Pressão , Feminino , Flavonoides/análise , Flavonoides/farmacologia , Inflamação/induzido quimicamente , Inflamação/metabolismo , Camundongos Endogâmicos ICR , Óxido Nítrico Sintase/antagonistas & inibidores , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Folhas de Planta/química , Saponinas/isolamento & purificação , Saponinas/farmacologia , Dermatopatias/metabolismo , Dermatopatias/prevenção & controle , Espectrometria de Massas em Tandem , Acetato de Tetradecanoilforbol/análogos & derivados
7.
Chem Biol Drug Des ; 98(4): 507-521, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34143939

RESUMO

Among the compounds of natural origin, diterpenes have proved useful as drugs for the treatment of cancer. Marine organisms, such as soft corals and algae, are a promising source of diterpenes, being a rich and unexplored source of cytotoxic agents. This study evaluated a library of 32 natural and semisynthetic marine diterpenes, including briarane, cembrane, and dolabellane nuclei, with the aim of determining their cytotoxicity against three human cancer cell lines (A549, MCF7, and PC3). The three most active compounds were submitted to a flow cytometry analysis in order to determine induction of apoptosis against the A549 cell line. An NMR analysis was conducted to determine and evaluate the interactions between active diterpenes and tubulin. These interactions were characterized by a computational study using molecular docking and MD simulations. With these results, two cembrane and one chlorinated briarane diterpenes were active against the three human cancer cell lines, induced apoptosis in the A549 cell line, and showed interactions with tubulin preferably at the taxane-binding site. This study is a starting point for the identification and optimization of the marine diterpenes selected for better antitumor activities. It also highlights the power of integrating NMR studies, computational predictions, and in vitro assays in the search for compounds with antitumor activity.


Assuntos
Antozoários/química , Antineoplásicos/química , Produtos Biológicos/química , Misturas Complexas/química , Diterpenos/química , Bibliotecas de Moléculas Pequenas/química , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Produtos Biológicos/farmacologia , Linhagem Celular Tumoral , Misturas Complexas/farmacologia , Biologia Computacional , Diterpenos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Halogenação , Humanos , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Bibliotecas de Moléculas Pequenas/farmacologia , Relação Estrutura-Atividade
8.
J Nat Prod ; 84(4): 1373-1384, 2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33822611

RESUMO

Brown algae and soft corals represent the main marine sources of dolabellane diterpenes. The antiviral activity of dolabellanes has been studied for those isolated from algae, whereas dolabellanes isolated from soft corals have been barely studied. In this work, a collection of dolabellane diterpenes consisting of five natural and 21 semisynthetic derivatives was constructed, and their antiviral activities against Zika (ZIKV) and Chikungunya (CHIKV) viruses were tested. Dolabellatrienone (1) and (1R,7R,8R,11S)-7,8-epoxy-13-keto-dolabella-3,12(18)-diene (2), isolated from Eunicea genus soft corals, were employed to obtain 21 dolabellane and dolastane diterpenes by reactions such as allylic oxidations, reductions, acid-catalyzed epoxide ring opening, and acetylations. All of the compounds were identified by a combination of one- and two-dimensional NMR, mass spectrometry, and X-ray diffraction experiments. The cytotoxicites against Vero cells and the antiviral activities against ZIKV and CHIKV was tested to calculate the half-maximal effective concentration (EC50) and selectivity indexes (SIs). In general, the addition of oxygen-containing functional groups improved the bioactivity of dolabellane and dolastane diterpenes against ZIKV and CHIKV replication. Compound 9 showed an EC50 = 0.92 ± 0.08 µM and SI = 820 against ZIKV.


Assuntos
Antozoários/química , Antivirais/farmacologia , Vírus Chikungunya/efeitos dos fármacos , Diterpenos/farmacologia , Zika virus/efeitos dos fármacos , Animais , Antivirais/síntese química , Região do Caribe , Chlorocebus aethiops , Colômbia , Diterpenos/síntese química , Estrutura Molecular , Oxigênio/química , Células Vero
9.
J Agric Food Chem ; 69(9): 2919-2931, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33621072

RESUMO

The leaves of Passiflora ligularis Juss (known as sweet granadilla for its edible fruits) are a crop byproduct that is discarded. With the aim of contributing to give value-added products from these crop by-side products to farmers of Colombian Andes, we carried out a 1H-NMR-metabolomics analysis of polar extracts from leaves collected in three locations and stored in two conditions in order to identify glucosyl-hydrolase inhibitors. Variations in the metabolic profile and the bioactivity among samples were analyzed by orthogonal partial least square discriminant analysis. Thus, 1H-NMR signals related to polyphenolic compounds, saponins, and amino acids were correlated with higher inhibitory activities. Moreover, a targeted NMR and HPLC-MS/MS analysis allowed the identification of 14 polyphenolic compounds and the structural characterization of a new triterpenoid saponin, ligularoside A. The measurements of IC50 values for α-amylase and α-glycosidase inhibitors allowed the identification of quercetin-3-O-ß-glucoside, kaempferol-3-O-ß-glucoside, and ligularoside A as the most active compounds. These results suggest that P. ligularis leaves are a source of glucosyl-hydrolase inhibitors and lay the foundation for exploring additional applications.


Assuntos
Passiflora , Saponinas , Triterpenos , Inibidores de Glicosídeo Hidrolases , Espectroscopia de Ressonância Magnética , Metabolômica , Extratos Vegetais , Folhas de Planta , Espectrometria de Massas em Tandem , alfa-Amilases
10.
Opt Lett ; 45(17): 4662-4665, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32870825

RESUMO

We report spatiotemporal pure-rotational coherent anti-Stokes Raman spectroscopy (CARS) in a one-dimensional imaging arrangement obtained with a single ultrafast regenerative amplifier system. The femtosecond pump/Stokes photon pairs, used for impulsive excitation, are delivered by an external compressor operating on a ∼35% beam split of the uncompressed amplifier output (2.5 mJ/pulse). The picosecond 1.2 mJ probe pulse is produced via the second-harmonic bandwidth compression (SHBC) of the ∼65% remainder of the amplifier output (4.5 mJ/pulse), which originates from the internal compressor. The two pump/Stokes and probe pulses are spatially, temporally, and repetition-wise correlated at the measurement, and the signal generation plane is relayed by a wide-field coherent imaging spectrometer onto the detector plane, which is refreshed at the same repetition rate as the ultrafast regenerative amplifier system. We demonstrate 1 kHz cinematographic 1D-CARS gas-phase thermometry across an unstable premixed methane/air flame-front, achieved with a single-shot precision <1% and accuracy <3%, 1.4 mm field of view, and an excellent <20µm line-spread function.

11.
Microbiol Res ; 239: 126507, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32563122

RESUMO

Actinobacteria are the major source of bioactive secondary metabolites and are featured in the search for antimicrobial compounds. We used nuclear magnetic resonance (RMN)-metabolic profiling and multivariate data analysis (MVDA) to correlate the metabolites' production of Streptomyces sp. PNM-9 from the algae Dictyota sp. and their biological activity against the rice phytopathogenic bacteria Burkholderia spp. The compounds 2-methyl-N-(2'-phenylethyl)-butanamide (1) and 3-methyl-N-(2'-phenylethyl)-butanamide (2) were identified through MVDA and 2D NMR experiments in the organic extract of a 15-days LB media culture of Streptomyces sp. PNM-9. Compounds 1 and 2 were isolated and their structures confirmed by one- and two-dimensional NMR and mass spectrometry (MS) data. Compounds 1 and 2 were active against the rice pathogenic bacteria Burkholderia glumae (ATCC 33,617) displaying minimal inhibitory concentration (MIC) values of 2.43 mM and 1.21 mM, respectively. The metabolomics-guided approach employing NMR-metabolic profiling was useful for marine microbial bioprospecting and suggested Streptomyces sp. PNM-9 strain and its compounds as a potential control against phytopathogenic bacteria.


Assuntos
Antibacterianos/farmacologia , Burkholderia/efeitos dos fármacos , Meios de Cultura/farmacologia , Metabolômica/métodos , Streptomyces/química , Amidas/química , Amidas/farmacologia , Antibacterianos/isolamento & purificação , Organismos Aquáticos/química , Bioprospecção , Burkholderia/patogenicidade , Meios de Cultura/química , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle
12.
Phytochemistry ; 172: 112272, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32032827

RESUMO

Banana passion fruit of the Passiflora genus, are commercially cultivated on a small to medium scale, mainly as edible fruits or as components of traditional herbal medicines. This subgenus comprises several species and hybrid specimens that grow readily in the wild. Due to their taxonomical complexity, many of these species have recently been reclassified (Ocampo Pérez and Coppens d'Eeckenbrugge, 2017), and their chemical profile has still to be determined. In this study, an 1H NMR-based platform was applied to the chemical profiling of seven wild species of the Passiflora subgenus, and UHPLC-DAD-MS was additionally used for the identification of phenolic compounds. A total of 59 compounds were detected including 26 O- and C-glycosidated flavonoids and polyphenols, nine organic acids, seven amino acids, GABA, sucrose, glucose, myo-inositol, and five other non-identified compounds. Two of the identified compounds are the previously undescribed C-glycosyl flavonoids, apigenin-4'-O-ß-glucopyranosyl, 8-C-ß-(6″acetyl)-glucopyranoside and apigenin-4-O-ß-glucopyranosyl-8-C-ß-neohesperidoside. These C-glycosyl flavonoids were isolated to confirm their proposed structures by NMR and LCMS analysis. The PCA score plots obtained from the 1H NMR data of the studied Passiflora samples showed P. cumbalensis and P. uribei as the species with the most distinguishable chemical profile. In addition, a correlation analysis using OPLS-DA was conducted between 1H-NMR data and the quorum quenching activity (QQ) of Chromobacterium violaceum ATCC 31532. This analysis revealed P. lehmannii, and P. uribei extracts to be the most active, and apigenin-4'-O-ß-glucopyranosyl, 8-C-ß-(6″acetyl)-glucopyranoside and apigenin-4-O-ß-glucopyranosyl-8-C-ß-neohesperidoside were identified as possibly responsible for the QQ activity. To confirm this, QQ activity of both compounds was tested against C. violaceum ATCC 3153. An inhibition of violacein production of 0.135 mM (100 µg/mL) and 0.472 mM (300 µg/mL) was observed for apigenin-4'-O-ß-glucopyranosyl,8-C-ß-(6″acetyl)-glucopyranoside and apigenin-4-O-ß-glucopyranosyl-8-C-ß-neohesperidoside respectively, while bacterial growth was unaffected in both cases. Furthermore, both compounds showed the ability to inhibit the production of the toxoflavin of the phytopathogen Burkholderia glumae ATCC 33617.


Assuntos
Musa , Passiflora , Flavonoides , Frutas , Percepção de Quorum
13.
Mar Drugs ; 18(1)2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31861453

RESUMO

The Caribbean soft coral Erythropodium caribaeorum is a rich source of erythrolides-chlorinated briarane diterpenoids. These compounds have an ecological role as feeding deterrents, with a wide variation in their composition depending on the location where the sample is collected. In Colombia, this soft coral can be found at different locations in the Caribbean Sea including Santa Marta, Islas del Rosario, and Providencia-three environmentally different coral reef areas in the south and southwest Caribbean Sea. In order to evaluate differences in erythrolide composition, the metabolic profiles of samples from each of these locations were analyzed by HPLC-MS. Principal component analysis showed changes in the diterpene composition according to the sample origin. Diterpenes from samples collected at each location were isolated to describe the three chemotypes. The chemotype from Santa Marta was highly diverse, with the new erythrolides W and X together with eight known erythrolides. The sample from Islas del Rosario showed a low diversity chemotype constituted by high amounts of erythrolide A and B. The chemotype from Providencia showed low chemical diversity with only two main compounds-erythrolide V and R. Evaluation of cytotoxic activity against the human cancer cell lines PC-3, MCF7, and A549 showed erythrolides A and B as the more active compounds with IC50 values in the range from 2.45 to 30 µM.


Assuntos
Antozoários/química , Metaboloma , Animais , Antozoários/metabolismo , Região do Caribe , Colômbia , Recifes de Corais , Diterpenos/química , Humanos
14.
Acta biol. colomb ; 24(2): 243-254, May-ago. 2019. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1010854

RESUMO

ABSTRACT Blooms of marine benthic cyanobacteria are recurrent in several locations at the Colombian Caribbean. In these events, cyanobacteria grow over the substrate and benthic organisms although their effect has not been fully assessed. This study evaluated interactions between cyanobacteria and hermatypic corals, in order to identify any deleterious effects that could be related to allelopathic mechanisms. Organic extracts from cyanobacteria collected in San Andres, Old Providence and Rosario islands were tested against embryos of the reef-building coral Orbicella annularis. The indirect effect of cyanobacterial extracts was also assessed by resuspending the extracts in seawater and monitoring polyp retraction and recovery of the coral Madracis mirabilis (=auretenra). Additionally, the effect of direct contact between cyanobacterial extracts and the coral Porites porites was assessed by incorporating cyanobacterial extracts into Phytagel™ gels and placed in direct contact with the coral. After 24, 48 and 72 h of exposure, chromatographic profiles of associated zooxanthellae was evaluated by HPLC. A deleterious effect on the zooxanthellae was evidenced by an increase in pheophytin, a degradation product from chlorophyll. The competitive abilities of algae and cyanobacteria should be considered as a constraint to reef restoration initiatives. Cyanobacteria have the ability to compete with corals due to their growth rates, defenses against herbivory and potentially allelopathic mechanisms.


RESUMEN Afloramientos de cianobacterias marinas bentónicas son recurrentes en varias localidades del Caribe colombiano. En estos eventos, las cianobacterias crecen sobre el sustrato y organismos bentónicos sin que su efecto se haya evaluado completamente. Este estudio evaluó interacciones entre cianobacterias y corales hermatípicos con el fin de identificar efectos perjudiciales que podrían estar relacionados con mecanismos alelopáticos. Extractos orgánicos de cianobacterias recolectadas en las islas de San Andrés, Providencia y las Islas del Rosario fueron evaluados contra embriones del coral hermatípico Orbicella annularis. También se evaluó el efecto indirecto de extractos de cianobacterias resuspendidos en agua de mar para determinar retracción de pólipos y recuperación del coral Madracis mirabilis (=auretenra). Adicionalmente, se evaluó el efecto del contacto directo de extractos de cianobacterias y el coral Porites porites mediante la incorporación de los extractos en geles de PhytagelTM dispuestos en contacto directo con el coral. Después de 24, 48 y 72 h de exposición, los perfiles cromatográficos de las zooxantelas asociadas al coral fueron evaluados por HPLC. Un efecto negativo sobre las zooxantelas se evidenció por el incremento en feofitina, producto de degradación de la clorofila. Las capacidades competitivas de algas y cianobacterias debieran considerarse como un factor que podría incidir negativamente en iniciativas de restauración arrecifal. Las cianobacterias tienen la capacidad de competir con corales debido a sus tasas de crecimiento, defensas contra herbivoría y potenciales mecanismos alelopáticos.

15.
J Antibiot (Tokyo) ; 72(10): 744-751, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31243345

RESUMO

Two cyclotetrapeptides, henceforth named Provipeptides A (1) and B (2), along with five known diketopiperazines (3-7) were isolated from the liquid culture of marine Streptomyces sp. 161a recovered from a sample of sea grass Bryopsis sp. The structures of cyclotetrapeptides and diketopiperazines (DKPs) were established by 1D and 2D NMR data, MS, and by comparison with literature data. The absolute stereochemistry of compounds cyclo-(L-Pro-L-Leu-D-Pro-L-Phe) 1 and cyclo-(-Pro-Ile-Pro-Phe) 2 was established by the Marfey's method. Compound 1 showed antibacterial activity against rice phytopathogenic strains Burkholderia glumae (MIC = 1.1 mM) and Burkholderia gladioli (MIC = 0.068 mM), compound 2 was active only against B. glumae (MIC = 1.1 mM), and DKP cyclo-[L-Pro-L-Leu] 5 showed to be active against B. gladioli (MIC = 0.3 mM) and B. glumae (MIC = 2.4 mM). Compounds 1 and 2 showed 65% and 50% inhibition of Colletotrichum gloeosporioides (yam pathogen) conidia germination, respectively at a concentration of 1.1 mM.


Assuntos
Anti-Infecciosos/isolamento & purificação , Burkholderia/efeitos dos fármacos , Colletotrichum/efeitos dos fármacos , Meios de Cultura/química , Oligopeptídeos/isolamento & purificação , Peptídeos Cíclicos/isolamento & purificação , Anti-Infecciosos/farmacologia , Dioscorea/microbiologia , Testes de Sensibilidade Microbiana , Estrutura Molecular , Oligopeptídeos/farmacologia , Oryza/microbiologia , Peptídeos Cíclicos/farmacologia , Análise Espectral , Streptomyces/crescimento & desenvolvimento , Streptomyces/metabolismo
16.
Front Microbiol ; 10: 290, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30858835

RESUMO

Bacterial Panicle Blight caused by Burkholderia glumae is a major disease of rice, which has dramatically affected rice production around the world in the last years. In this study we describe the assessment of three Streptomyces isolates as biocontrol agents for B. glumae. Additionally, the presence of other plant-growth promoting abilities and their possible beneficial effects upon their inoculation on rice plants was evaluated as an ecological analysis for their future inoculation in rice crops. Two isolates (A20 and 5.1) inhibited growth of virulent B. glumae strains, as well as a wide range of bacterial and fungal species, while a third strain (7.1) showed only antifungal activity. In vitro tests demonstrated the ability of these strains to produce siderophores, Indoleacetic acid (IAA), extracellular enzymes and solubilizing phosphate. Greenhouse experiments with two rice cultivars indicated that Streptomyces A20 is able to colonize rice plants and promote plant growth in both cultivars. Furthermore, an egfp tagged mutant was generated and colonization experiments were performed, indicating that Streptomyces A20 -GFP was strongly associated with root hairs, which may be related to the plant growth promotion observed in the gnotobiotic experiments. In order to characterize the antimicrobial compounds produced by strain A20 bacteria, mass spectrometry analyses were performed. This technique indicated that A20 produced several antimicrobial compounds with sizes below 3 kDa and three of these molecules were identified as Streptotricins D, E and F. These findings indicate the potential of Streptomyces A20 as a biocontrol inoculant to protect rice plants against bacterial diseases.

17.
Nat Prod Res ; 33(24): 3533-3540, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29863905

RESUMO

The acetylcholinesterase inhibitory activity of 89 organic extracts from marine organisms was evaluated through a TLC bioautography methodology. Extracts from soft corals (Eunicea and Plexaura) were the most active compared with extracts from sponges. The bioguided chemical study of the most active extract, obtained from Pseudoplexaura porosa, led to the isolation of a diterpene with spectroscopic properties consistent to those published to the cembrane Steylolide. However, further analysis by X-ray diffraction indicated that the compound was the 14-acetoxycrassine (1), correcting the structure reported to the Styelolide. Additionally, the acetylcholinesterase inhibitory activity of fourteen cembranoids (2-15) isolated from soft corals Eunicea knighti and Pseudoplexaura flagellosa was evaluated. Cembranoids 2, 3 and 4 were the most active compounds in the TLC bioassay. Then, the most promising cembranoids, 14-acetoxycrassine (1) and asperdiol (2), were tested quantitatively and they exhibited IC50 values of 1.40 ± 0.113 and 0.358 ± 0.130 µM, respectively.


Assuntos
Antozoários/química , Organismos Aquáticos/química , Inibidores da Colinesterase/análise , Animais , Região do Caribe , Inibidores da Colinesterase/química , Diterpenos/química , Diterpenos/isolamento & purificação , Concentração Inibidora 50 , Programas de Rastreamento , Estrutura Molecular
18.
Rev. Soc. Colomb. Oftalmol ; 52(2): 110-116, 2019. ilus., tab., graf.
Artigo em Espanhol | LILACS, COLNAL | ID: biblio-1094901

RESUMO

Introducción: el encapsulamiento de la ampolla o también llamado "quiste de Tenon" alrededor del dispositivo puede comprometer el funcionamiento valvular, aumentando la presión intraocular y así requiriendo procedimientos quirúrgicos adicionales. Objetivo: describir la eficacia y seguridad de la resección de quiste encapsulado en implante valvular de Ahmed en el control de la presión intraocular. Diseño de estudio: estudio observacional, retrospectivo, serie de casos. Método: se hizo un análisis de los pacientes a los que se les realizó resección de quiste encapsulado con un seguimiento a 6 meses, se excluyeron pacientes con antecedente de procedimiento ciclodestructivo, agudeza visual no percepción de luz, alteración del estado de conciencia, cirugía combinada y /o seguimiento postoperatorio menor de 3 meses. Resultados: se analizaron 14 ojos de los cuales 9 (64.3%) eran mujeres. El promedio de edad fue 56.1 con un rango entre 14 ­ 83 años. La presión intraocular preoperatoria promedio fue 26.7± 6.6 mmHg con una reducción estadísticamente significativa desde el primer día posoperatorio 9.8 ± 0.93 mmHg y al sexto mes 13.7 ± 0.94 mmHg (p 0.005). En el primer mes posoperatorio se logró reducción significativa en el número de medicamentos hipotensores (p 0.003), el cual se estabilizó al tercer mes y al sexto mes no presentó diferencia estadísticamente significativa (p 0.078). Conclusión: la resección de quiste encapsulado es un procedimiento efectivo para lograr el control de la presión intraocular en pacientes con glaucomas refractarios y/o no controlados con pocas complicaciones asociadas.


Background: the encapsulation of the bleb or so-called (Tenon cyst) around the device can compromise valve function, increasing intraocular pressure and thus requiring additional surgical procedures. Objective: to describe the efficacy and safety of encapsulated cyst resection in Ahmed valve implant for the control of intraocular pressure. Study design: observational study, retrospective cases series. Method: an analysis was made of the patients who underwent encapsulated cyst resection between January 2016 and August 2017 with a 6-month follow-up, patients with a history of cyclodestructive procedure, visual acuity of no light perception, altered state of consciousness, combined surgery and / or postoperative follow-up of less than 3 months were excluded. Results: 14 eyes were analyzed, of which 9 (64.3%) were women. The average age was 56.1 with a range between 14 - 83 years. he average preoperative intraocular pressure was 26.7 ± 6.6 mmHg with a statistically significant reduction from the first postoperative day 9.8 ± 0.93 mmHg and at the sixth month 13.7 ± 0.94 mmHg (p 0.005). In the fi rst postoperative month there was a significant reduction in the number of hypotensive drugs (p 0.003), which stabilized at the third month and at the sixth month did not present a statistically significant difference (p 0.078). Conclusion: encapsulated cyst resection is an effective procedure to achieve control of intraocular pressure in patients with refractory and / or uncontrolled glaucoma with few associated complications.


Assuntos
Glaucoma/cirurgia , Procedimentos Cirúrgicos Oftalmológicos , Oftalmopatias , Cápsula de Tenon/cirurgia , Pressão Intraocular
19.
Int J Ophthalmol ; 11(4): 635-640, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29675383

RESUMO

AIM: To assess the efficacy and safety of patterned laser trabeculoplasty (PLT) as an adjunctive treatment in open angle glaucoma (OAG) or ocular hypertension (OHT) patients who were under antiglaucoma medical treatment. METHODS: This study was a retrospective review of primary or secondary OAG patients and OHT patients with medically uncontrolled (≥18 mm Hg) intraocular pressure (IOP) who underwent 360° PLT from June 2016 to August 2016. Follow-up visits at week 1, and 1, 3 and 6mo were performed. IOP, best corrected visual acuity (BCVA), complications and eye drop glaucoma medication were recorded at each follow-up visit. Success was defined as IOP reduction ≥20% from baseline. RESULTS: Forty-one eyes of 25 patients were included in this study. Pre-treatment mean IOP was 20.2±1.6 mm Hg. After PLT, IOP was 19.3±5.2, 16.1±2.7, 17.1±3.7 and 16.3±3.5 mm Hg, at 1wk, 1, 3 and 6mo, respectively. IOP reduction from baseline was statistically significant from the first month, remaining stable at 6mo (P<0.001). PLT success at 6mo of follow-up was 48.78%. The number of glaucoma medication per eye (P=0.10) and the mean BCVA both remained constant (P=0.37). Complications included transient IOP spikes in 4 eyes (9.8%) and peripheral anterior synechiae in 7 eyes (17.1%). CONCLUSION: PLT is an effective and safe method for the management of patients with OHT or OAG as an adjunctive therapy. Additional larger studies should be designed to verify the long-term stability of IOP reduction with this laser technology.

20.
Carbohydr Res ; 461: 4-10, 2018 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-29549750

RESUMO

The fruit of Physalis peruviana is widely used in traditional Colombian medicine as an antidiabetic treatment. The aim of the study reported here was to identify the compounds responsible for the hypoglycemic activity using the α-amylase inhibition test. Bioguided fractionation of a dichloromethane extract of the sticky exudate that covers the fruit allowed the isolation and identification of three new sucrose esters, named as peruvioses C-E (1-3), along with the known peruvioses A (6), B (5) and F (4), the structures of which were elucidated by extensive NMR and MS experiments. These compounds proved to be responsible for the hypoglycemic activity observed in the extract. Peruviose D (2) showed the highest activity, with an inhibitory activity value of 84.8%. This is the first study to establish the potential of sucrose esters as α-amylase inhibitors and to explain the hypoglycemic effect that has traditionally been attributed to gooseberry fruit.


Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Ésteres/química , Ésteres/farmacologia , Frutas/química , Physalis/química , Exsudatos de Plantas/química , Exsudatos de Plantas/farmacologia , Sacarose/química , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/metabolismo , Espectroscopia de Ressonância Magnética , Espectrometria de Massas
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