ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2021-05-19
    Description: A method involving flash chromatography, semi-preparative phenylhexyl RP HPLC-DAD-ELSD combined with analytic polar-RP HPLC-DAD, was applied to separate and purify six highly nitrogenated bases and a bicyclic amidine alkaloid, the major components of the marine sponge Niphates digitalis. Their structures were identified as 1,8-diazabicyclo[5.4.0]undec-7- ene (1), deoxycytidine (2), phenylalanine (3), adenosine (4), deoxyguanosine (5), adenine (6) and thymidine (7) on the basis of spectroscopic data analyses. This is the first report of these compounds in a marine sponge belonging to the Niphates genus and the first evidence of the presence of 1 from a natural source.
    Description: Published
    Description: Marine sponge, Niphates digitalis, nucleosides, nucleobases, antimalarial activity, cytotoxicity
    Keywords: Cytotoxicity ; Sponges ; Sponges ; Cytotoxicity
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2021-05-19
    Description: Daily topical application of the aqueous ethanolic extract of the marine sea grass, Thalassia testudinum, on mice skin exposed to UVB radiation resulted in a dose dependent recovery of the skin macroscopic alterations over a 6-day period. Maximal effect (90%) occurred at a dose of 240 μg/cm2, with no additional effects at higher doses. Bioassay-guided fractionation of the plant extract resulted in the isolation of thalassiolin B (1). Topical application of 1 (240 μg/cm2) markedly reduces skin UVB-induced damage. In addition, thalassiolin B scavenged 2,2-diphenyl-2-picrylhydrazyl radical with an EC50=100 μg/ml. These results suggest that thalassiolin B is responsible for the skin regenerating effects of the crude extract of T. testudinum
    Description: Published
    Description: Flavonoids, Thalassiolin B, DPPH scavenged, antioxidant activity, Skin regenerating activity, Thalassia testudinum
    Keywords: Chemistry ; Pharmacology ; Chemistry ; Pharmacology
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2021-05-19
    Description: Marine sponges (Porifera) have drawn the attention from a broad number of researchers all over the world. These animals and their simbionts are specialized in chemical warfare, producing biologically active chemical substances as an effective defense against predators. They have been considered a goldmine to chemists, from which have been discovered more than 6000 novel structures; many of them, with enormous biomedical applications, mainly against cancer, but also against bacteria, viruses and other diseases. Some of the sponge-derived drugs are available in the market, such as: Ara-A (antiviral) and Ara-C (anticancer), but there are diverse bioactive compounds under clinical trials. In Cuba, the researches related to the isolation of compounds from marine sponges are scarce and the initial studies were about pharmacological evaluations of extracts and fractions. In recent studies, three sponges were investigated (Agelas cerebrum, Niphates digitalis and Pandaros acanthifolium), from which were isolated and identified 45 metabolites, two of them were isolated for the first time as natural products, including the discovery of 30 novel metabolites, dividing in two new families of steroidal saponins with uncommon chemical characteristics and potential against several parasitic protozoa and tumor human cell lines.
    Description: Published
    Description: marine sponges, novel compounds, bioactive metabolites, antiparasitic, antitumoral
    Keywords: Sponges ; Organic compounds ; Antiparasitic agents
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2021-05-19
    Description: Bioguided fractionation of Agelas cerebrum crude extract resulted in isolation of four bromopyrrole and four bromopyrrole aminoimidazole alkaloids, identified as 5-bromopyrrole-2-carboxylic acid (1), 4-bromopyrrole-2-carboxylic acid (2), 3,4-bromopyrrole-2-carboxylic acid (3), 4,5-bromopyrrole-2-carboxylic acid (4), oroidin (5), bromoageliferin (6), dibromoageliferin (7) and dibromosceptrin (8) on the basis of spectroscopic data analyses (UV, IR, HRMS, 1D and 2D NMR) and comparison with literature data. This is the first report of compounds 2 and 3 in a marine sponge belonging to the Agelas genus and the first evidence of the presence of 1 from a natural source.
    Description: Published
    Description: Agelas cerebrum, bromopyrrole alkaloids, antitumoral, antiprotozoal activity
    Keywords: Chemistry ; Alkaloids ; Sponges ; Alkaloids ; Sponges ; Chemistry
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2021-05-19
    Description: Las esponjas marinas (Porifera) han atraído la atención de un gran número de científicos alrededor del mundo. Estos animales y sus simbiontes utilizan mecanismos de defensa química, basados en la producción de compuestos biologicamente activos que utlizan para protegerse de posibles depredadores. Son considerados una mina de oro para los químicos y se han descubierto más de 6000 estructuras novedosas, muchas de ellas con enormes aplicaciones biomédicas, fundamentalmente contra el cáncer, pero también contra diversas bacterias, virus y otras enfermedades. Algunos de los fármacos derivados de esponjas se encuentran disponibles en el mercado, tal es el caso Ara-A (antiviral) y de la Ara-C (antitumoral), pero existen diversos compuestos bioactivos en ensayos clínicos. En Cuba, las investigaciones relacionadas con compuestos obtenidos de esponjas marinas son muy escasas, los descubrimientos iniciales se desarrollaron en el campo farmacológico y solamente en extractos o fracciones. En estudios recientes, se investigaron tres esponjas (Agelas cerebrum, Niphates digitalis y Pandaros acanthifolium), a partir de las cuales se aislaron e identificaron 45 metabolitos, dos de ellos fueron nuevos productos naturales y 30 resultaron metabolitos novedosos, pertenecientes a dos nuevas familias de saponinas esteroidales con características químicas poco comunes y efecto sobre varios parásitos protozoarios, así como contra varias líneas celulares de carcinoma humano.
    Description: Marine sponges (Porifera) have drawn the attention from a broad number of researchers all over the world. These animals and their simbionts are specialized in chemical warfare, producing biologically active chemical substances as an effective defense against predators. They have been considered a goldmine to chemists, from which have been discovered more than 6000 novel structures; many of them, with enormous biomedical applications, mainly against cancer, but also against bacteria, viruses and other diseases. Some of the sponge- derived drugs are available in the market, such as: Ara-A (antiviral) and Ara-C (anticancer), but there are diverse bioactive compounds under clinical trials. In Cuba, the researches related to the isolation of compounds from marine sponges are scarce and the initial studies were about pharmacological evaluations of extracts and fractions. In recent studies, three sponges were investigated (Agelas cerebrum, Niphates digitalis and Pandaros acanthifolium), from which were isolated and identified 45 metabolites, two of them were isolated for the first time as natural products, including the discovery of 30 novel metabolites, dividing in two new families of steroidal saponins with uncommon chemical characteristics and potential against several parasitic protozoa and tumor human cell lines.
    Description: Published
    Description: novel compounds, antiparasitic, antitumoral
    Keywords: Chemical compounds ; Sponges ; Sponges ; Chemical compounds ; Bioactive compounds
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2021-05-19
    Description: The marine phanerogam Syringodium filiforme, known as “manatee grass”, is a common species that grows in coastal areas associated to Thalassia testudinum. With the aim to describe some of its possible chemical characteristics, this study was performed with a sample of 1.2kg, collected in March 2009, in Guanabo beach, Havana, Cuba. The sample was dried (less than 12% humidity) and a total extract prepared; other three extracts were prepared with the use of solvents of increasing polarity. The phytochemical screening and analytical determinations of each fraction were undertaken Total polyphenol content was determined using pyrogallol as reference´s standard; chlorophyll a and b and anthocyanin content were also quantified. Total extract and fractions antioxidant activity were evaluated by using the free radical scavenging activity assay with 1,1-Diphenyl-2-Picrylhydrazyl reactive (knowing as DPPH´s method). The phytochemical screening of the different extracts detected the presence of high concentrations of flavonoids, phenols, terpenes, antocyaninns, reducing sugars and alkaloids. The total extract and methanol fraction showed significant free radical scavenging properties, while the petroleum ether fraction showed moderate activity, and the chloroform fraction and the aqueous soluble precipitate (residual salt) obtained didn’t show antioxidant properties against free radicals. The results of this work confirmed the potentialities of this species for biological purposes
    Description: Published
    Description: Syringodium filiforme, phytochemistry, phenolic compounds, antioxidant activity
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2021-05-19
    Description: Hydrogen peroxide bleaching of sodium alginate from seaweeds oh the Sargassum genus was studied. The influence of H2O2 concentration (percentage of H2O2 on a dry weight alginate basis, w/w) and NaOH/H2O2 ratio (% NaOH/% H2O2, both referred to a dry weight alginate basis, w/w) on the molecular weight, color removal and content of Fe3+ ions of bleached alginate samples was investigated by UV and IR spectroscopies, colorimetric determination of Fe3+ ions and vapor pressure osmometry. Higher yield, purity and molecular weight of alginate were obtained using 3% (or less) of hydrogen peroxide and a NaOH/H2O2 ratio of 1.2 for bleaching.
    Description: Published
    Description: sodium alginate, Sargassum
    Keywords: Bleaching ; Bleaching
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2021-05-19
    Description: The Cuban marine flora and fauna is characterized by its richness in species that represents an extraordinary natural source of unexplored biomolecular diversity. Many of those biomolecules could represent important tools for industrial applications. For this reason, in our Centre the main aim was focused on the isolation, purification and characterization of bioactive compounds present in marine invertebrates with particular emphasis on sponges, cnidarians, seaweeds and marine plants. Micro organisms represent also an important source of biologically active compounds that were included in our studies. In our Institution, research is performed by a multidisciplinary team. The purpose of this article is to review the most important results of the Centre of Marine Bioproducts in the last few years.
    Description: Published
    Description: sustainable use, marine bioproducts.
    Keywords: Marine organisms
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2021-05-19
    Description: Las algas constituyen un recurso natural de gran variedad y abundancia en los arrecifes coralinos cubanos. En la literatura científica han sido descritos efectos de extractos y compuestos aislados de algas pardas sobre el Sistema Nervioso Central, entre ellos, acciones depresora, antidepresiva y anticonvulsivante. En este estudio se presentan los resultados obtenidos en la evaluación neurofarmacológica de los extractos etanólicos (10%) procedentes de las algas pardas: Dictyota pinnatifida y Turbinaria turbinata sobre la conducta exploratoria, tiempo de sueño inducido por tiopental y prueba de esconder esferas. Se utilizaron ratones, albinos, machos, de la línea OF-1, de peso corporal entre 18 y 22 gramos y se emplearon dosis de 40, 200 y 1000 mg/kg, por vía oral. Los extractos de D. pinnatifida (40 mg/kg) y T. Turbinata (200 y 1000mg/kg) disminuyeron significativamente la actividad exploratoria, lo cual pudiera relacionarse con la presencia de terpenos en los mismos. En la prueba de tiempo de sueño la dosis de 1000 mg/kg del extracto de D. pinnatifida produjo una potenciación significativa de su duración, mientras que la administración del extracto de T. turbinata no modificó la duración del tiempo de sueño pero aumentó significativamente el período de latencia (40 y 1000 mg/kg). En la prueba de esconder esferas, la dosis de 1000 mg/kg de ambos extractos disminuyó significativamente el número de esferas escondidas, lo que indica la presencia de compuestos con efecto ansiolítico. Los resultados sugieren que ambos extractos presentan efectos de sedación y ansiolíticos. Se discute el interés e importancia en continuar las investigaciones en esta temática.
    Description: The algae constitute a natural resource of great variety and abundance in the Cuban coralline reefs. In the scientific literature actions of extracts and isolated compounds of brown algae have been described on the Nervous System, among them, depressant, antidepressive and anticonvulsivant effects. In this study the results obtained in the neuropharmacological evaluation of ethanolic extracts (10%) coming from brown algae: Dictyota pinnatifida and Turbinaria turbinata are presented. The models employees were the following ones: exploratory behavior, sleeping time induced by thiopental and marble burying test. Groups of 10 mice albino males were used, (OF-1 line, 18-22 g of corporal weight). The extracts of D. pinnatifida (40 mg/kg) and T. Turbinata (200 and 1000mg/kg) diminished significantly the exploratory activity, and this effect could be related with the presence of terpens in the same ones. In the test of sleeping time induced by thiopental the dose of 1000 mg/kg of the extract of D. pinnatifida produced a significant potentiation of its duration, while the administration of the extract of T. turbinata didn't modify the duration of the sleeping time but it increased significantly the period of latency (40 and 1000 mg/kg. In the marble burying test, the dose of 1000 mg/kg of both extracts diminished the number of hidden spheres significantly, suggesting an anxiolytic effect. It is discussed the interest and importance in continuing the investigations in this field.
    Description: Brown Algae, exploratory behavior; Sleeping time; Marble burying test; Anxiolytic; Dictyota pinnatifida; Turbinaria turbinata.
    Repository Name: AquaDocs
    Type: Preprint
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2020-07-01
    Print ISSN: 1070-664X
    Electronic ISSN: 1089-7674
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...