Polysaccharides algal

The role of plant and algal polysaccharides as non-cytotoxic antitumour substances has been discussed.  

Some of the polysaccharides found in algae are identical or very similar to those found in land plants. Starch is one of them. Algal starches have, however, smaller molecules (lower DP) as compared to starch from land plants. Cellulose and several hemicelluloses are also found in algae. 

Several other less common polysaccharides were isolated from algae [62] and are indicated in Table 7.8.1. Some of these polysaccharides also have a certain degree of sulfation. 

Even MS/MS analyses (with initial Py-DIP and Cl in the mass spectrometer) were performed on some algal polysaccharides [3a] with successful differentiation between several starting materials (see also Section 7.1). 

FI mass spectra were proven informative in algal polysaccharide analysis [2]. Characteristic Py-Fi mass spectra were reported for agarose, aiginic acid, laminaran, etc. Also, Py-GC/MS studies were done on algal polysaccharides [64a,64b]. The identification of pyrolysis products for several polysaccharides from red algae showed, as expected, compounds commonly obtained during polysaccharide pyrolysis. A list of several compounds found in these pyrolysates is shown in Table 7.8.2. 

Microbial polysaccharides comprise a wide variety of carbohydrate macromolecules, some of them with considerable structural complexity. Three main types of microbial polysaccharides are known  

Two types of binding site for Ca + ions have been recognized in an acidic polysaccharide from the coccoliths of Emiliania huxleyi One of them has a low affinity for Ca + ions and is possibly associated with the hexuronic acid residues, whereas the other unidentified site exhibits a high affinity for Ca + ions. 

An enzyme preparation from the marine brown alga Pelvetia canaliculata contained both alginate 5-epimerase and alginate lyase activities.Ca ions activated both enzymes, but Mn ions only inhibited lyase activity. Increasing concentrations of substrate D-mannuronanate removed the inhibition of lyase activity by Mn ions. 

The osmotic coefficients of Na , K , and Ca counter-ions have been determined in aqueous solutions of K-, l- and X-carrageenans and the results were correlated with those calculated from the limiting law of Manning. An ordered secondary structure exists in k- and t-carrageenans, whose stability can be discussed as a function of temperature, ionic strength, and nature of the counterion. 

A x-carrageenanase from Pseudomonas carrageenovora has been isolated and purified and its identity has been confirmed by an inspection of the products 

Addition of carrageenan to flours from soft wheats gave a product that was more akin to the flour from hard wheats in its bread-making quality.  

The non-Newtonian behaviour of the viscosity of K-carrageenan solutions at various shear rates increased on addition of D-glucose or sucrose.The results were explained in terms of changes in the solute-solute interactions. 

The C n.m.r. spectroscopy of red seaweed DL-galactans belonging to the agar and carrageenan groups has been studied. Signal assignments could be made for 

The agar composition of different generations of Gracilaria verrucosa has been determined. There was little difference between yield, fractionation pattern, or properties of agars from fertile weeds, but juvenile (sterile) plants gave agars of low yield and quality. The gel-forming properties could be improved by alkali treatment. 

When the intrinsic viscosity of an anionic polysaccharide such as carrageenan is plotted against the reciprocal of the square root of the ionic strength, a linear plot 

Smestad, A. Haug, and S. Myklestad, Acta Chem. Scand. (15), 1974, 28, 662. 

Shimahara and N. Sugiyama, Agric. and Biol. Chem. Japan), 1974, 38, 2569. 

Bourne, M. L. Megarry, and E. E. Percival, J. Carbohydrates, Nucleosides, Nucleotides, 

Nishikawa, K. Ohki, K. Takahashi, G. Kurono, F. Fukuoka, and M. Emori, Chem. and 

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BraynerCoradin, T., Fievet-Vincent, F., Livage, J. and Fievet, F. (2005) Algal polysaccharide capsule-templated growth of magnetic nanoparticles. New Journal of Chemistry, 29,... 

Sulfated alcohol ethoxylates rat oral LD50 values, 8 445 Sulfated alcohols, 23 537 Sulfated algal polysaccharides,... 

Anhydro-1-deoxy-D-glycero-D-gulo-octalo-pyranose and 2,7-anhydro isomer (c) Methyl ethers 2% NPGS 210 bacterial and algal polysaccharides 570... 

The algal polysaccharides resembled the relatively simplified structures of tile neutral mucilages, as in the case of carrageenan A wider spectrum of struclures is found in Ihc bacterial gums, which arc generally of the highly branched type exuded by higher plants,... 

Another cause for a floe, particularly in the autumn, can be the presence of algal polysaccharides in the water. Although these polysaccharides are soluble in water at neutral pH values, they will precipitate from solution when the water is made acid. To check for the presence of polysaccharides in the water the following test should be carried out. 

The D-galactose-containing polysaccharides are varied, and mostly heterogeneous in composition. L-Galactose occurs only rarely in polysaccharides of higher plants414 however, it is found abundantly in algal polysaccharides.415,418... 

E. Percival and R. H. McDowell, Chemistry and Enzymology of Marine Algal Polysaccharides, Academic Press, New York, 1967. 

R. J. Perrier Prostaglandins from sugars T. J. Painter Algal polysaccharides... 

Painter TJ (1983) Algal polysaccharides. In Aspinall GO (ed) The polysaccharides. Academic Press, New York, pp 195-285... 

Percival E (1970) Algal polysaccharides. In Pigman W, Horton D (eds) The carbohydrates, vol IIB. Academic Press, New York, pp 541-544 Post AF, Dubinsky Z, Wyman K, Falkowski PG (1985) Physiological-responses of a marine planktonic diatom to transitions in growth irradiance. Mar Ecol Prog Ser 25 141-149... 

D. J. Stancioff and N. F. Stanley, Infrared and chemical studies on algal polysaccharides, Proc. Int. Seaweed Symp., 6 (1969) 595-609. 

M. Duckworth and W. Yaphe, Definitive assay for pyruvic acid in agar and other algal polysaccharides, Chem. Ind., 23 (1970) 747-748. 

W. Yaphe, Colorimetric determination of 3,6-anhydrogalactose and galactose in marine algal polysaccharides, Anal. Chem., 32 (1960) 1327-1330. 

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