The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
René H. Wijffels - One of the best experts on this subject based on the ideXlab platform.
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Seasonal Growth Rate of the Sponge Haliclona oculata (Demospongiae: Haplosclerida)
Marine Biotechnology, 2008Co-Authors: Marieke Koopmans, René H. WijffelsAbstract:The interest in sponges has increased rapidly since the discovery of potential new pharmaceutical compounds produced by many sponges. A good method to produce these compounds by using aquaculture of sponges is not yet available, because there is insufficient knowledge about the nutritional needs of sponges. To gain more insight in the nutritional needs for growth, we studied the growth rate of Haliclona oculata in its natural environment and monitored environmental parameters in parallel. A stereo photogrammetry approach was used for measuring growth rates. Stereo pictures were taken and used to measure volumetric changes monthly during 1 year. Volumetric growth rate of Haliclona oculata showed a seasonal trend with the highest average specific growth rate measured in May: 0.012 ± 0.004 day^−1. In our study a strong positive correlation ( p
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seasonal growth rate of the sponge Haliclona oculata demospongiae haplosclerida
Marine Biotechnology, 2008Co-Authors: Marieke Koopmans, René H. WijffelsAbstract:The interest in sponges has increased rapidly since the discovery of potential new pharmaceutical compounds produced by many sponges. A good method to produce these compounds by using aquaculture of sponges is not yet available, because there is insufficient knowledge about the nutritional needs of sponges. To gain more insight in the nutritional needs for growth, we studied the growth rate of Haliclona oculata in its natural environment and monitored environmental parameters in parallel. A stereo photogrammetry approach was used for measuring growth rates. Stereo pictures were taken and used to measure volumetric changes monthly during 1 year. Volumetric growth rate of Haliclona oculata showed a seasonal trend with the highest average specific growth rate measured in May: 0.012 ± 0.004 day−1. In our study a strong positive correlation (p < 0.01) was found for growth rate with temperature, algal biomass (measured as chlorophyll a), and carbon and nitrogen content in suspended particulate matter. A negative correlation (p < 0.05) was found for growth rate with salinity, ammonium, nitrate, nitrite, and phosphate. No correlation was found with dissolved organic carbon, suggesting that Haliclona oculata is more dependent on particulate organic carbon.
Michael R Boyd - One of the best experts on this subject based on the ideXlab platform.
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a new pentacyclic sulfated hydroquinone from the marine sponge Haliclona sp
Tetrahedron Letters, 2002Co-Authors: Heidi R Bokesch, Amy C Stull, Lewis K Pannell, Tawnya C Mckee, Michael R BoydAbstract:Abstract A new pentacyclic sulfated hydroquinone, phuklona sulfate, has been isolated from the marine sponge Haliclona sp. collected near Phuket Island, Thailand. The structure was elucidated by a variety of spectroscopic methods including 1D and 2D NMR experiments. Phuklona sulfate contains a novel triterpenoid carbon skeleton linked to a sulfated hydroquinone moeity.
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a new isoquinoline alkaloid from the marine sponge Haliclona species
Journal of Natural Products, 2001Co-Authors: Mohammad A Rashid, Kirk R Gustafson, Michael R BoydAbstract:Two isoquinoline alkaloids, including the new compound 1, were isolated from the cytotoxic fractions of an aqueous extract of the marine sponge Haliclona sp. The structures of these compounds were established as 1-hydroxymethyl-7-methoxyisoquinolin-6-ol (1) and mimosamycin (2) by conventional spectroscopic methods and by comparison with related compounds. Mimosamycin (2) was the principal cytotoxin with an IC50 of approximately 10 μg/mL against melanoma and ovarian human tumor cell lines.
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rottnestol a new hemiketal from the sponge Haliclona sp
Tetrahedron, 1995Co-Authors: Karen L Erickson, John A Beutler, John H Cardellina, Michael R BoydAbstract:Summary Rottnestol, a new hemiketal, was isolated from an Australian collection of the marine sponge Haliclona sp. Its structure was deduced as 3 from 1H, 13C, COSY, HMQC, HMBC and nOe NMR studies. Hemiketal 3 was readily converted to its epimer, 4, and the methyl ketal of 4.
Marieke Koopmans - One of the best experts on this subject based on the ideXlab platform.
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Seasonal Growth Rate of the Sponge Haliclona oculata (Demospongiae: Haplosclerida)
Marine Biotechnology, 2008Co-Authors: Marieke Koopmans, René H. WijffelsAbstract:The interest in sponges has increased rapidly since the discovery of potential new pharmaceutical compounds produced by many sponges. A good method to produce these compounds by using aquaculture of sponges is not yet available, because there is insufficient knowledge about the nutritional needs of sponges. To gain more insight in the nutritional needs for growth, we studied the growth rate of Haliclona oculata in its natural environment and monitored environmental parameters in parallel. A stereo photogrammetry approach was used for measuring growth rates. Stereo pictures were taken and used to measure volumetric changes monthly during 1 year. Volumetric growth rate of Haliclona oculata showed a seasonal trend with the highest average specific growth rate measured in May: 0.012 ± 0.004 day^−1. In our study a strong positive correlation ( p
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seasonal growth rate of the sponge Haliclona oculata demospongiae haplosclerida
Marine Biotechnology, 2008Co-Authors: Marieke Koopmans, René H. WijffelsAbstract:The interest in sponges has increased rapidly since the discovery of potential new pharmaceutical compounds produced by many sponges. A good method to produce these compounds by using aquaculture of sponges is not yet available, because there is insufficient knowledge about the nutritional needs of sponges. To gain more insight in the nutritional needs for growth, we studied the growth rate of Haliclona oculata in its natural environment and monitored environmental parameters in parallel. A stereo photogrammetry approach was used for measuring growth rates. Stereo pictures were taken and used to measure volumetric changes monthly during 1 year. Volumetric growth rate of Haliclona oculata showed a seasonal trend with the highest average specific growth rate measured in May: 0.012 ± 0.004 day−1. In our study a strong positive correlation (p < 0.01) was found for growth rate with temperature, algal biomass (measured as chlorophyll a), and carbon and nitrogen content in suspended particulate matter. A negative correlation (p < 0.05) was found for growth rate with salinity, ammonium, nitrate, nitrite, and phosphate. No correlation was found with dissolved organic carbon, suggesting that Haliclona oculata is more dependent on particulate organic carbon.
Yoel Kashman - One of the best experts on this subject based on the ideXlab platform.
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isohalitulin and haliclorensins b and c three marine alkaloids from Haliclona tulearensis
Journal of Natural Products, 2010Co-Authors: Hagit Sorek, Amira Rudi, Maurice Aknin, Emile M Gaydou, Yoel KashmanAbstract:Three new alkaloids, designated isohalitulin (4), haliclorensin B (5), and haliclorensin C (6), were isolated from two specimens of the Madagascan sponge Haliclona tulearensis, collected at two locations in Salary Bay, north of Tulear. Their structures were elucidated by extensive spectroscopic means. Alkaloids 4−6 exhibited mild toxicity in the brine shrimp test.
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Haliclonyne, a new highly oxygenated polyacetylene from the marine sponge Haliclona species.
Journal of Natural Products, 2000Co-Authors: Liat Chill, And Aharon Miroz, Yoel KashmanAbstract:: Haliclonyne (1), a new polyacetylene carboxylic acid, has been isolated from the marine sponge Haliclona sp. collected in the Gulf of Eilat. The structure of haliclonyne, a C(47) oxo-octahydroxy-dienetetrayne carboxylic acid, was elucidated by interpretation of NMR and mass spectra of 1 and two of its derivatives.
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halitulin a new cytotoxic alkaloid from the marine sponge Haliclona tulearensis
Tetrahedron Letters, 1999Co-Authors: Yoel Kashman, Ganit Korengoldshlager, M Garcia D Gravalos, Michael SchleyerAbstract:Abstract Halitulin ( 2 ), a novel bisquinolinylpyrrole has been isolated from the sponge Haliclona tulearensis . Its structure was elucidated mainly on the basis of spectroscopic data as well as chemical modifications. Halitulin was found to be cytotoxic against several tumor cells: P-388, A-549, HT-29 and MEL-28 in concentrations of 12–25 ng/ml.
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haliclorensin a novel diamino alkaloid from the marine sponge Haliclona tulearensis
Journal of Natural Products, 1998Co-Authors: Ganit Korengoldshlager, Yoel Kashman, Michael SchleyerAbstract:Haliclorensin (1), a novel diamino alkaloid possessing an azacyclodecane ring, has been isolated from the sponge Haliclona tulearensis. Its structure was elucidated on the basis of spectroscopic data, as well as by comparison with γ-amino azacycloalkanes.
Shigeki Matsunaga - One of the best experts on this subject based on the ideXlab platform.
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Perplexing distribution of 3-alkylpyridines in haplosclerid sponges
2020Co-Authors: Leontine E. Becking, Yoichi Nakao, Nicole J. De Voogd, Rob W. M. Van Soest, Nobuhiro Fusetani, Shigeki MatsunagaAbstract:Abstract: In this study we reviewed the natural product literature for the distribution of 3-alkylpyridines among sponge taxa. In parallel, we traced selected 3-alkylpyridines, amphitoxins, in three haplosclerid genera (Amphimedon, Callyspongia, Haliclona) in order to establish the utility of such compounds as genuine chemotaxonomic markers. We confirmed that this group of compounds had been almost solely extracted from sponges of the order Haplosclerida. Three groups of compounds within the 3-alkylpyridine derivatives were noteworthy, as they appear to be concentrated in restricted taxonomic units within the order Haplosclerida: 1) polymers, 2) cyclic dimers, and 3) bicyclic dimers. There was a concentration of the polymer amphitoxin in the families Niphatidae and Callyspongiidae of the suborder Haplosclerina, and more particularly in the genera Amphimedon and Callyspongia. Our experimental results reconfirmed the presence of amphitoxin in Callyspongia (Euplacella) biru, but we were unable to trace any amphitoxins or 3-alkylpyridines of any kind in Callyspongia (Callyspongia) truncata, Haliclona sp., and Amphimedon aff. queenslandica. Assuming that these classifications are correct, our results diminish the value of both amphitoxins and 3-alkylpyridines as monophyletic markers.
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ceratodictyols 1 glyceryl ethers from the red alga sponge association ceratodictyon spongiosum Haliclona cymaeformis
Journal of Natural Products, 2009Co-Authors: Takuya Akiyama, Rob W. M. Van Soest, Reiko Ueoka, Shigeki MatsunagaAbstract:Six 1-glyceryl ethers (1−6) were isolated from the red alga−sponge assemblage Ceratodictyon spongiosum/Haliclona cymaeformis. Structural assignments were conducted by interpretation of spectroscopic data and the modified Mosher’s method. Four allylic alcohols were obtained as a pair of epimeric mixtures (3/4 and 5/6). These glyceryl ethers exhibited weak cytotoxic activity against HeLa human cervical cancer cells.
