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| 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 |
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| Nogueiras, C.; Spengler, I.; Guerra, J.O.; Ortiz, Y.; Torres, S.; García, T.H.; Romeu, C.R.; Regalado, E.L.; González, T.A.; Perera, W.H.; Lacret, R.. |
| Interest in natural products as a source for innovation in drug discovery and agrochemicals is still growing worldwide. Natural products, whose immense diversity has been appreciated for many years, may become in a rich source of novel chemical structures. Our country is a rich source of both biological and chemical diversity which may be useful as a source of novel chemical structures. Even when natural products have been used as medicinal agents for many years in Cuba, their use as agrochemicals are still limited. Thus, the present review focuses on recent advances in the studies on natural products performed by the “Centro de Estudios de Productos Naturales, CEPN” during the past ten years, highlighting on those with potential use as biomedical... |
| Tipo: Journal Contribution |
Palavras-chave: Products; Chemical compounds; Bioactive compounds; Products; Chemical compounds; Http://aims.fao.org/aos/agrovoc/c_6211; Http://aims.fao.org/aos/agrovoc/c_49870. |
| Ano: 2010 |
URL: http://hdl.handle.net/1834/3986 |
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| 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 |
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| 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 |
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| 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 |
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| Regalado, E.L.; Jiménez-Romero, C.; Genta-Jouve, G.; Tasdemir, D.; Amade, P.; Nogueiras, C.; Thomas, O.P.. |
| Seven novel steroid glycosides, acanthifoliosides A-F (1-6) and the methyl ester of 6 (7), were isolated from the marine sponge Pandaros acanthifolium as minor components. Acanthifoliosides are characterized by a rare C-15 and C-16 oxidized D ring which was previously found in saponins produced by starfishes. Very uncommon is the presence of additional sugar residues at C-15 or C-16. Their structures were determined on the basis of extensive spectroscopic analyses, including two-dimensional NMR and HRESIMS data. The absolute configurations of the aglycones were assigned by comparison between experimental and TDDFT calculated CD spectra of 1, whereas the absolute configurations of the monosaccharide units were determined by chiral GC analyses of the acid... |
| Tipo: Journal Contribution |
Palavras-chave: Sponges; Sponges; Http://aims.fao.org/aos/agrovoc/c_7321. |
| Ano: 2011 |
URL: http://hdl.handle.net/1834/3866 |
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