Algae, red

The red algae (Rhodophyta) are the most prolific sources of halogenated organics in the marine environment, and this topic was recently reviewed (Fenical, 1975). At least six orders, representing some ten families of red algae are now known to produce a wide variety of structure types from halo-methanes (C,) to halogenated products derived from squalene (C30). Within this group are aromatic and acyclic compounds produced from acetate (poly-ketide) biosynthesis and monoterpenes (Cio), sesqui- (Cu) and diterpenoids (C2o)- The structures of well over 200 compounds have now been firmly established. 

The red alga Laurencia produces an unusual group of bromine and chlorine-bearing ethers based upon an n-pentadecane skeleton, of probable fatty acid origin. Specific examples of the approximately 25 described substances are the halogenated ethers 8 and 9, isolated from L. glandulifera in Japan (Irie et al., 1965) and an undescribed Laurencia species from the Gulf of California, Mexico (Fenical et al., 1974). 

Perhaps the most exciting of the acetate-derived halogenated organics are 

It should be pointed out that the carbon tetrahalides are difficult to rationalize via this mechanistic proposal. A conceivable but unprecedented possibility would be the reaction of the haloform-produced trihalomethyl anion an enzymatically produced halonium ion (X ) or its equivalent. 

3-ones (23) (Siuda et al., 1975 McConnell and Fenical, 1977a, b). Two related algae, Ptilonia australasica and Delisea fimbriata are also known to produce Cs ketones as in 23, and D. fimbriata from both Antarctic and Australiein waters is also reported to produce a unique group of polyhalo-lactones such as 24 (Pettus et al., 1977 Kazlauskas, et al., 1976, 1977a). 

Irish moss (Chondrus crispus) is a small, purplish-colored red seaweed that grows up to 7.8 inches (20 cm). Underwater, Irish moss fronds look iridescent, but in very strong light, they may take on a green color. The plant is commercially important for the gel-like carbohydrate in its cell walls, which is used to make food additives, textile sizing, and cosmetics. In Japan, the same chemical is used in the manufacture of shampoo because it gives a gloss to hair. Consequently, Irish moss is often harvested from lower intertidal zones. 

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Figure 4 Halogenated terpenoid and polyketide metabolites isolated from red algae in the genera Laureucia and Plocamium...

Spiramycin is a macrolide that inhibits protein biosynthesis by blocking transfer of the aminoacyl-rRNA along the ribosome in a unique organelle of the parasite, termed apicoplast. The apicoplast is a remnant of a secondary endosymbiosis of a red algae and is only found in the phylum sporozoa. 

Abe, T., Masuda, M., Suzuki, T. and Suzuki, M. 1999. Chemical races in the red alga Laurencia nipponica (Rhodomelaceae, Ceramales) Phycol. Res. 47 87-95. 

Amico, V., Caccamese, S., Neri, P., Russo, G. and Foti, M. 1991. BrasUane-type ses-quiterpenoids from the Mediterraanean red alga Laurencia obtusa. Phytochemistry 30 1921-1928. 

Compagnini, A. and Toscana R. M. 1986. Paciferol from the Mediterranean red alga... 

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. 

Kbnig, G. M., Wright, A. D., and Linden, A. 1999. Plocamium hamatum and its monoter-penes chemcal and biological investigations of the tropical marine red alga. Phytochemistry 52 1047-1053. 

Oztunc, A., Imre, S., Loiter, H. and Wagner, H. 1991. Two C-15 bromoalleles form the red alga Laurencia obtusa. Phytochemistry 30 255-258. 

Stierle, D. B. and Sims, J. J. 1979. Marine natural products—V. Polyhalogenated cychc monoter-penes from the red alga Plocamium cartilagineum of Antarctica. Tetrahedron 35 1261-1265. 

Suzuki, M. and Kurosawa, E. 1978. Two new halogenated sesquiterpenes from the red alga Laurencia majuscula. Tetrahedron Lett. 4805-4808. 

Kurosawa, E. and Kurata, K. 1987. Majusculone, a novel norchamigrane-type metabolite from the red alga Laurencia majuscula Harvey. Buh. Chem. Soc. Japan 60 3795-3796. 

Chlorophyll d 445,686 green algae Some red algae and Blue-green -CHO -CH, -CH2CH3 -CHjCHjCOO-phytyl Double Single... 

The red microalga Porphyridium aerugineum is a source of blue color. This species is different from other red microalgae in that it lacks red phycoerythrin and its phycocyanin is C-phycocyanin rather than the R-phycocyanin that accompanies phycoerythrin found in many red algae and in other Porphyridium species. However, the biochemicals produced by P. aerugineum are similar to those of other red microalgae, e.g., sulfated polysaccharides, carotenoids, and lipids. An alternative source of C-phycocyanin is Spirulina platensis. ... 

Pedersen M (1976) A brominating and hydroxylating peroxidase from the red alga Cystoclonium purpureum. Physiol Plant 37 6-11. 

There are two general types of seaweed gums of commercial importance, the brown and the red algae (Figure 6) ( I). 

Sodium alginate is the principal brown algae gum, while the red algae are of two practical types ... 

Fujiwara K (2006) Total Synthesis of Medium-Ring Ethers from Laurencia Red Algae. 5 ... 

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