Sargassum

Chlorophyta kelp and Sargassum Green algae includes Volvox, 7,000... 

Davis, T.A., Llanes, F., Volesky, B. and Mucci, A. (2003) Metal selectivity of Sargassum spp. And their alginates in relation to their a-L-guluronic acid content and conformation. Environmental Science S. Technology, 37, 261-267. 

Dimeric structures are possible as exemplified by the leptosins, from a strain of Leptosphaeria (a fungus isolated from the marine alga Sargassum tortile). Some of these, e.g. leptosin A 11, may have up to 4 sulfur atoms across the diketopiperazine ring system.23 Various leptosins have antitumor and cytotoxic properties. 

Shikimates, which include phenylalanine, tyrosine, tryptophan, and their derivatives, are represented by many aromatic natural products, including hydroquinones found inbrownalgae such as Sargassum (Segawaand Shirahama 1987). Flavonoids are a structural class of shikimates found in plants, including isoflavonoids or neo-flavonoids, as is the y-pyrone (coumarin) core structure (Knaggs 2003). 

Segawa M, Shirahama H (1987) New plastoquinones from the brown alga Sargassum sagami-anum var. yezoense. Chem Lett 7 1365-1366... 

Shimizu Y, Gupta S, Masuda K, Maranda L, Walker CK, Wang R (1989) Dinoflagellate and other microalgal toxins chemistry and biochemistry. Pure Appl Chem 61 513-516 Sieburth JM, Conover JT (1965) Sargassum tannon, an antibiotic which retards fouling. Nature 208 52-53... 

Sargassum S. fllipendula Widespread in temperate and tropical waters. Atlantic Is., North America, Caribbean Is., South America, Africa, South-west Asia, and South-east Asia... 

Steinberg 1995 Sargassum vestitum Alaria nana Fucales Faminariales Simulated herbivory Phlorotannins... 

Alg G isolated along with Alg A from Sargassum fluitans and tentatively assigned to the genus Photobacterium (33). Pure enzyme was evaluated on poly(GulA) (Brown, B J., Preston, J.F., University of Rorida, unpublished). 

Also from the China seas, the phaeophyte Sargassum sp. yielded an unidentified fungal endophyte with antibacterial activity. The culture of the fungus (No. ZZF36) led to isolation of two new, 6-oxo-de-O-methyllasiodiplodin (52) and ( )-etheno-lasiodiplodin (53), and three known lactones, lasiodiplodin (54), de-O-methyllasiodiplodin (55), and 5-hydroxy-de-O-methyllasiodiplodin (56). Compounds 54-56 exhibited low to moderate antibacterial and antifungal activities. 

Brown algae in the genera Stypopodium and Sargassum, in a kind of opportunistic association, provide a refugee for grazeable seaweeds, promoting biodiversity (Hay 1992, 1996). Distasteful metabolites released by the brown algae are responsible for these effects. 

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