Consulta: creatorFacets:"Laguna, A."
Registros recuperados: 11
Data/hora: 03/06/2024 04:50:25

Polar Alkaloids from the Caribbean Marine Sponge Niphates digitalis
Provedor de dados: 20
Autores: Regalado, E.L.; Mendiola, J.; Laguna, A.; Nogueiras, C.; Thomas, O.P.
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.
Tipo: Journal Contribution
Palavras-chave: Sponges; Cytotoxicity; Cytotoxicity; Sponges; Http://aims.fao.org/aos/agrovoc/c_34251; Http://aims.fao.org/aos/agrovoc/c_7321.
Ano: 2010
URL: http://hdl.handle.net/1834/3860

Repair of UVB-Damaged Skin by the antioxidant sulphated flavone glycoside Thalassiolin B Isolated from the marine plant Thalassia testudinum Banks ex König
Provedor de dados: 20
Autores: Regalado, E.L.; Rodríguez, M.; Menéndez, R.; Concepción, A.A.; Nogueiras, C.; Laguna, A.; Rodríguez, A.A.; Williams, D.E.; Lenzo-Luaces, P.; Valdés, O.; Hernandez, Y.
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
Tipo: Journal Contribution
Palavras-chave: Chemistry; Pharmacology; Chemistry; Pharmacology; Http://aims.fao.org/aos/agrovoc/c_1522; Http://aims.fao.org/aos/agrovoc/c_5760.
Ano: 2009
URL: http://hdl.handle.net/1834/3865

Actividad antioxidante del alga Ulva fasciata Delile sometida a distintos niveles de contaminación marina
Provedor de dados: 20
Autores: Hernández, Y.; Laguna, A.; Fernández, M.D.; Valdés, O.; Regalado, E.L.
Ha sido demostrado, por otros autores, que el alga Ulva fasciata Delile posee una actividad antioxidante promisoria y en el presente trabajo evaluamos si la actividad antioxidante de muestras de esta alga puede ser influenciada por la adsorción de metales, pesados y otros por parte del alga. U. fasciata fue colectada en tres zonas de las costas de la Ciudad de la Habana que presentan diferentes niveles de eutrofización: 1) la desembocadura del Río Quibú, un río que atraviesa una importante zona industrial de la capital cubana y en la cual la concentración de metales acumulados por el alga fue mayor; 2) la zona del Malecón habanero, que recibe la contaminación de la bahía de la Habana y del Río Almendares pero no de forma directa, donde presentó valores...
Tipo: Journal Contribution
Palavras-chave: Algae; Marine environment; Heavy metals; Marine environment; Heavy metals; Algae; Http://aims.fao.org/aos/agrovoc/c_4610; Http://aims.fao.org/aos/agrovoc/c_2223; Http://aims.fao.org/aos/agrovoc/c_258.
Ano: 2008
URL: http://hdl.handle.net/1834/2919

Decoloración de alginato de sodio extraído de las algas pardas marinas del género sargassum con el uso de peróxido de hidrógeno
Provedor de dados: 20
Autores: Regalado, E.L.; Laguna, A.; Torres, M.; Sabatier, J.D.; Hernández, M.; Ferrer, A.E.; Nogueiras, C.
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.
Tipo: Journal Contribution
Palavras-chave: Bleaching; Bleaching; Http://aims.fao.org/aos/agrovoc/c_953.
Ano: 2007
URL: http://hdl.handle.net/1834/3855

Caribbean marine biodiversity as a source of new compounds of biomedical interest and others industrial applications
Provedor de dados: 20
Autores: Nuñez, R.; Garateix, A.; Laguna, A.; Fernández, M.D.; Ortiz, E.; Llanio, M.; Valdés, O.; Rodríguez, A.; Menéndez, R.
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...
Tipo: Journal Contribution
Palavras-chave: Marine organisms.
Ano: 2006
URL: http://hdl.handle.net/1834/3649

Marine sponges as a source of new bioactive substances
Provedor de dados: 20
Autores: Regalado, E.L.; Laguna, A.; Martínez, J.R.
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...
Tipo: Journal Contribution
Palavras-chave: Sponges; Chemical compounds; Bioactive compounds; Chemical compounds; Sponges; Http://aims.fao.org/aos/agrovoc/c_49870; Http://aims.fao.org/aos/agrovoc/c_7321.
Ano: 2010
URL: http://hdl.handle.net/1834/4039

Actividad antioxidante de algas y plantas marinas de la plataforma insular cubana
Provedor de dados: 20
Autores: Valdés, O.; Hernádez, Y.; Fernández, M.D.; Hernández, I.; Rodriguez, M.; Cano, M.; Laguna, A.; Díaz, C.; Cabrera, B.
En el presente trabajo se estudia la capacidad antioxidante de varios extractos, acuosos e hidro-alcohólicos obtenidos a partir de algas y plantas marinas de la plataforma insular cubana. A todos los extractos se les determinó su contenido de polifenoles, proteínas, lípidos y azúcares totales, así como la actividad Superóxido Dismutasa (SOD). Todos los extractos evaluados mostraron una buena actividad antioxidante, con una CE50 inferior de 0,4 mg.ml-1. El contenido de polifenoles en los extractos de Ulva fasciata es menor el de las otras especies, aunque tanto el extracto hidro-alcohólico como el del alga seca e irradiada de dicha especie presentan una buena actividad antioxidante. El extracto hidro-alcohólico de Thalassia testudinum presenta el mayor...
Tipo: Journal Contribution
Palavras-chave: Proteins; Antioxidants; Proteins; Antioxidants; Http://aims.fao.org/aos/agrovoc/c_6259; Http://aims.fao.org/aos/agrovoc/c_511.
Ano: 2008
URL: http://hdl.handle.net/1834/2820

Las esponjas marinas como fuente de nuevas sustancias bioactivas.
Provedor de dados: 20
Autores: Regalado, E.L.; Laguna, A.; Martínez, J.R.
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...
Tipo: Journal Contribution
Palavras-chave: Sponges; Organic compounds; Antiparasitic agents.
Ano: 2010
URL: http://hdl.handle.net/1834/4129

Efecto antioxidante y contenido polifenólico de Syringodium filiforme (Cymodoceaceae)
Provedor de dados: 20
Autores: González García, K.L.; Valdés Iglesias, O.; Laguna, A.; Díaz Martínez, M.; González Lavaut, J.A.
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...
Tipo: Journal Contribution
Ano: 2011
URL: http://hdl.handle.net/1834/3910

Bromopyrrole alkaloids from the Caribbean sponge Agelas cerebrum
Provedor de dados: 20
Autores: Regalado, E.L.; Laguna, A.; Mendiola, J.; Thomas, O.P.; Nogueiras, C.
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.
Tipo: Journal Contribution
Palavras-chave: Alkaloids; Sponges; Chemistry; Chemistry; Alkaloids; Sponges; Http://aims.fao.org/aos/agrovoc/c_1522; Http://aims.fao.org/aos/agrovoc/c_269; Http://aims.fao.org/aos/agrovoc/c_7321.
Ano: 2010
URL: http://hdl.handle.net/1834/3862

Efectos neurofarmacológicos de extractos de algas marinas.
Provedor de dados: 20
Autores: Garateix, A.; García, T.; Buznego, M.T.; Ruenes, K.; Valdés, O.; Laguna, A.; Hernández, Y.; Guzmán, F.; Palmero, A.; Pérez-Saad, H.
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...
Tipo: Preprint
Ano: 2000
URL: http://hdl.handle.net/1834/3644