ChemInform Abstract: FURTHER CEMBRANOID DERIVATIVES FROM THE RED SEA SOFT CORALS ALCYONIUM FLACCIDUM AND LOBOPHYTUM CRASSUM

Seventy-one marine organisms representing different classes of marine fauna and flora were collected from the Red Sea. They include sponges, hydrozoan, soft corals, sea cucumber, ascidian, cyanobacteria, and macroalgae. The methanolic extracts were evaluated for their toxicity and settlement inhibition effects by using cultured Balanus amphitrite. Thirty-three extracts displayed antifouling effects: four samples were highly potent at 1 μg/mL with a percentage of settlement inhibition above 31%, twenty-two were potent at 10 μg/mL with a percentage of settlement inhibition between 16 and 30%, and seven were active at 10 μg/mL with a percentage of settlement inhibition between 0 and 15%. Two promising extracts were purified by employing several chromatographic techniques, leading to the isolation of 12 known compounds. The isolated compounds were evaluated for their antifouling activities and demonstrated potent antifouling effects with EC50 values of less than 10 μg/mL.

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Cytotoxicity and chemical profiling of the Red Sea soft corals Litophyton arboreum

Natural Product Research ◽

10.1080/14786419.2021.1974437 ◽

2021 ◽

pp. 1-5

Author(s):

Amany Hamouda Mahmoud ◽

Sabry A. H. Zidan ◽

Mamdouh Nabil Samy ◽

Abdallah Alian ◽

Usama Ramadan Abdelmohsen ◽

...

Keyword(s):

Red Sea ◽

Soft Corals ◽

Chemical Profiling

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Soft Corals Biodiversity in the Egyptian Red Sea: A Comparative MS and NMR Metabolomics Approach of Wild and Aquarium Grown Species

Journal of Proteome Research ◽

10.1021/acs.jproteome.6b00002 ◽

2016 ◽

Vol 15 (4) ◽

pp. 1274-1287 ◽

Cited By ~ 32

Author(s):

Mohamed A. Farag ◽

Andrea Porzel ◽

Montasser A. Al-Hammady ◽

Mohamed-Elamir F. Hegazy ◽

Achim Meyer ◽

...

Keyword(s):

Red Sea ◽

Soft Corals ◽

Nmr Metabolomics

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Chemical warfare in the sea: The search for antibiotics from Red Sea corals and sponges

Pure and Applied Chemistry ◽

10.1351/pac-con-08-10-07 ◽

2009 ◽

Vol 81 (6) ◽

pp. 1113-1121 ◽

Cited By ~ 28

Author(s):

Dovi Kelman ◽

Yoel Kashman ◽

Russell T. Hill ◽

Eugene Rosenberg ◽

Yossi Loya

Keyword(s):

Natural Products ◽

Chemical Defense ◽

Red Sea ◽

Close Association ◽

Marine Sponges ◽

Resistant Bacteria ◽

Rrna Gene ◽

Soft Corals ◽

Strong Activity ◽

Screening Programs

Marine sponges and corals are widely recognized as rich sources of novel bioactive natural products. These organisms are frequently colonized by bacteria. Some of these bacteria can be pathogenic or serve as beneficial symbionts. Therefore, these organisms need to regulate the bacteria they encounter and resist microbial pathogens. One method is by chemical defense. Antimicrobial assays performed with extracts of 23 Red Sea corals and sponges against bacteria isolated from their natural environment revealed considerable variability in antimicrobial activity. Soft corals exhibited appreciable activity; sponges showed variability, and stony corals had little or no activity. Among the soft corals, Xenia macrospiculata exhibited the highest activity. Bioassay-directed fractionation of the extract indicated that the activity was due to a range of compounds, one of which was isolated and identified as the diterpene desoxyhavannahine. Among the sponges, Amphimedon chloros exhibited strong activity. Bioassay-directed fractionation resulted in the isolation of the pyridinium alkaloid antibiotics, the halitoxins and amphitoxins. These compounds showed selective activity against specific bacteria, rather than being broad-spectrum. They were highly active against seawater bacteria, whereas bacteria associated with the sponge were resistant. This selective toxicity may be important in enabling certain bacteria to live in close association with their sponge host while it maintains a chemical defense against microbial pathogenesis. The halitoxin-resistant bacteria were identified by 16S rRNA gene analysis as Alphaproteobacteria, closely related to other Alphaproteobacteria isolated from various marine sponges. The study of microbial communities associated with sponges and corals has important implications for the production of symbiont-derived bioactive compounds and for the use of corals and sponges as source material for microbial diversity in screening programs for natural products.

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Further cembranoid derivatives from the Red Sea soft corals Alcyonium flaccidum and Lobophytum crassum

The Journal of Organic Chemistry ◽

10.1021/jo00331a003 ◽

1981 ◽

Vol 46 (18) ◽

pp. 3592-3596 ◽

Cited By ~ 39

Author(s):

Yoel Kashman ◽

Shmuel Carmely ◽

Amiram Groweiss

Keyword(s):

Red Sea ◽

Soft Corals

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Recent heterocyclic compounds from marine invertebrates: Structure and synthesis

Pure and Applied Chemistry ◽

10.1351/pac200779040491 ◽

2007 ◽

Vol 79 (4) ◽

pp. 491-505 ◽

Cited By ~ 8

Author(s):

Yoel Kashman ◽

Amira Rudi ◽

Doron Pappo

Keyword(s):

Natural Products ◽

Biological Activity ◽

Red Sea ◽

Heterocyclic Compounds ◽

Marine Invertebrates ◽

Soft Corals ◽

Marine Products

A large variety of unique heterocyclic natural marine products, without terrestrial counterparts, have been isolated from marine invertebrates, mainly sponges, ascidians, and soft corals. Many of these compounds display interesting biological activity. In this review, we report our recent studies on nitrogen-containing heterocyclic compounds ("alkaloids"), as well as some containing sulfur and oxygen, which have been isolated from Red Sea and Indo-Pacific organisms, and discuss progress on the synthesis of these natural products and structural analogs.

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