Algae, marine

Agar occurs as a cell-wall constituent of the red marine algae Rho ophyceae, from which it is extracted by hot water, and marketed as a dry powder, flakes, or strips. It dissolves in hot water and sets on cooling to a jelly at a concentration as low as 0-5%. Its chief uses are as a solid medium for cultivating micro-organisms, as a thickener, emulsion stabilizer in the food industry and as a laxative. 

For purposes of information one can compare these levels with those of plants (0.1 to 0.4%), mollusks (0.4%) and the human body (0.14%), but the highest levels are observed in marine algae (13% in Macrocytis pyrifera), and in the tissues of certain bacteria which can even contain elemental sulfur (25% in Beggiatoa Albea tissues). 

The importance of ozone in the stratosphere has been stressed in Section 9.3.8. The fact that ozone can be decomposed by the halogen monoxides CIO, BrO and 10 means that their presence in the stratosphere contributes to the depletion of the ozone layer. For example, iodine, in the form of methyl iodide, is released into the atmosphere by marine algae and is readily photolysed, by radiation from the sun, to produce iodine atoms which can react with ozone to produce 10 ... 

Manne Marine algae Marine apatites Marine applications Marine coatings Marine equipment Marine oil (menhaden)... 

Agar. Agar [9002-18-0] is obtained from a variety of red marine algae found along the coast of Japan. Food appUcations include fro2en desserts, confectionery products, and baked goods (92). 

Several analyses of known marine natural products according to the phylum of the source organism have revealed the richest sources of marine secondary metabolism (Figure It is clear from the data that marine algae and... 

Bromo-a-chamigrene, a compound isolated from marine algae, is... 

Isolated from marine algae, prelaureatin is thought to be biosynthesized from laurediol by the following route. Propose a mechanism. 

Remarkably, ketone halogenation also occurs in biological systems, particularly in marine alga, where dibromoacetaldehyde, bromoacetone, 1,1,1-tri-bromoacetone, and other related compounds have been found. 

The final step in an attempted synthesis of laurene, a hydrocarbon isolated from the marine alga Laurencin glandulifera, involved the Wittig reaction shown. The product obtained, however, was not laurene but an isomer. Propose a mechanism to account for these unexpected results. 

Bae, Y. M., and Hastings, J. W. (1994). Cloning, sequencing and expression of dinoflagellate luciferase DNA from a marine alga. Gonyaulax polyedra. Biochim. Biophys. Acta 1219 449-456. 

Morishita, H., et al. (2002). Cloning and characterization of an active fragment of luciferase from a luminescent marine alga, Pyrocystis lunula. Photochem. Photobiol. 75 311-315. 

Poller (498, 544) prepared a number of tributyl- and triphenyl-stan-nyl esters of sucrose hydrogenphthalate and succinate, and found that, as potential antifoulants, these were at least three times as effective against the marine alga, Enteromorpka, as bis(tributyltin) oxide, even though they contain almost one third the tin (see Table VIII). A new antifouling paint that also contains tributyltin compounds has recently been developed in Norway (545). 

Dimethyl sulfide production SO (CH3)2S Certain marine algae... 

Morton International, Inc. (1996a) Acute toxicity of monomethyl-tin trichloride to the marine alga, Skeletonema costatum. Study conducted by T.R. Wllbury Laboratories, Inc., Marblehead, MA,... 

The chloride anion is a major species in the oceans and plays an essential role in biochemistry. Compounds containing carbon-chlorine bonds occur much less frequently in nature. Volcanos emit some halocarbons, and marine algae generate chloromethane. Other marine species produce toxic organohalogen molecules that protect them from predators. Nevertheless, organic chlorine compounds are uncommon, and consequently there are few mechanisms that degrade them. 

Coll, J. C. and Wright, A. D. 1987. Tropical marine algae. I. New halogenated monoterpenes from Chondrococcus homemannii (Rhodophyta, Gigartinales, Rhizophyllidaceae). Australian J. Chem. 40 1893-1900. 

Gabrielson, P. W. and Scagel, R. F. 1989. The marine algae of British Columbia, northern Washington, and southeast Alaska division Rhodophyta (red algae), class Rhodophyceae, order Gigartinales, families Caulacanthaceae and Plocamiaceae. Can. J. Bot. 67 1221-1234. 

Howard, B. M., Nonomura, A. M. and Fenical, W. 1980. Chemotaxonomy in marine algae secondary metabolite synthesis by Laurencia in unialgal culture. Biochem. Syst. Ecol. 8 329-336. 

Chemical defenses and the susceptibihty of tropical marine algae to herbivores. 

Abrahamsson K, Ekdahl A, Collen J, et al. 1995. Marine algae—a source of trichloroethylene and perchloroethylene. Linmol Oceanogr 40 1321-1326. 

Halogenated phenols, particularly 2-bromo-, 2,4-dibromo-, and 2,4,6-tribromophenol, have been identified in automotive emissions and are the products of thermal reactions involving the dibromoethane fuel additive (Muller and Buser 1986). It could therefore no longer be assumed that such compounds are exclusively the products of biosynthesis by marine algae. 

The transformation of DDT to DDE—albeit in rather low yield—by elimination of one molecule of HCl has been observed in several marine algae (Rice and Sikka 1973). 

Rice CP, HC Sikka (1973) Uptake and metabolism of DDT by six species of marine algae. JAgric Food Chem 21 148-152. 

Interest in the possible persistence of aliphatic sulfides has arisen since they are produced in marine anaerobic sediments, and dimethylsulfide may be implicated in climate alteration (Charlson et al. 1987). Dimethylsnlfoniopropionate is produced by marine algae as an osmolyte, and has aronsed attention for several reasons. It can be the source of climatically active dimethylsulfide (Yoch 2002), so the role of specific bacteria has been considered in limiting its flux from the ocean and deflecting the prodncts of its transformation into the microbial sulfur cycle (Howard et al. 2006). 

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