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  • 1
    Publication Date: 2021-05-19
    Description: The chemical composition of the Caribbean sponge Pandaros acanthifolium was reinvestigated and led to the isolation of 12 new steroidal glycosides, namely, pandarosides E-J (1-6) and their methyl esters (7-12). Their structures were determined on the basis of extensive spectroscopic analyses, including two-dimensional NMR and HRESIMS data. Like the previously isolated pandarosides A-D (13-16), the new compounds 1-12 share an unusual oxidized D-ring and a cis C/D ring junction. The absolute configurations of the aglycones were assigned by interpretation of CD spectra, whereas the absolute configurations of the monosaccharide units were determined by chiral GC analyses of the acid methanolysates. The majority of the metabolites showed in Vitro activity against three or four parasitic protozoa. Particularly active were the compounds 3 (pandaroside G) and its methyl ester (9), which potently inhibited the growth of Trypanosoma brucei rhodesiense (IC50 values 0.78 and 0.038 μM, respectively) and Leishmania donoVani (IC50’s 1.3 and 0.051 μM, respectively).
    Description: Published
    Description: Pandaros, steroidal saponins, structure elucidation, stereochemistry, antiprotozoal
    Keywords: Sponges ; Sponges
    Repository Name: AquaDocs
    Type: Journal Contribution
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  • 2
    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
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  • 3
    Publication Date: 2021-05-19
    Description: The chemical composition of the Caribbean sponge Pandaros sp. was investigated and led to the isolation of seven new steroidal glycosides namely pandarosides A-D (1, 3, 4 and 6) along with the three methyl esters of pandarosides A, C, and D (2, 5 and 7). Their structures were characterized as 3β-[β-glucopyranosyl-(1→2)-β-glucopyranosyloxyuronic acid]-16-hydroxy- 5α,14β-poriferast-16-ene-15,23-dione (1) and its methyl ester (2), 3β-[β- glucopyranosyloxyuronic acid]-16-hydroxy-5α,14β-poriferast-16-ene-15,23-dione (3), 3β-[β- glucopyranosyl-(1→2)-β-glucopyranosyloxyuronic acid]-16-hydroxy-5α,14β-cholest-16-ene- 15,23-dione (4) and its methyl ester (5), 3β-(β-glucopyranosyloxyuronic acid)-16-hydroxy- 5α,14β-cholest-16-ene-15,23-dione (6) and its methyl ester (7) on the basis of detailed spectroscopic analyses, including 2D NMR and HRESI-MS studies. Pandarosides A-D and their methyl esters (1-7) are all characterized by a rare 2-hydroxycyclopentenone D-ring with a 14β configuration.
    Description: Published
    Description: Marine sponge, Pandaros, steroidal glycosides, structure elucidation, stereochemistry
    Keywords: Sponges ; Sponges
    Repository Name: AquaDocs
    Type: Journal Contribution
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  • 4
    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
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  • 5
    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
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  • 6
    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
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  • 7
    Publication Date: 2021-05-19
    Description: 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 methanolysates. Some of the acanthifoliosides exhibit moderate antiprotozoal activity but to a lesser extent than the most potent pandarosides.
    Description: La version original de este artículo está disponible en la Editorial Elsevier
    Description: Published
    Description: steroidal saponin, Pandaros, NMR, Circular dichroism
    Keywords: Sponges ; Sponges
    Repository Name: AquaDocs
    Type: Journal Contribution
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