Galactans structure

J.W. Van de Vis, Characterization and mode of action of enzymes degrading galactan structures of arabinogalactans. Thesis Wageningen Agricultural University (1994). 

R. Falshaw and R. H. Fumeaux, Chemotaxonomy of New Zealand red algae in the family Giga-rtinaceae (Rhodophyta) based on galactan structures from the tetrasporophyte life-stage, Carbohydr. Res., 344 (2009) 210-216. 

In spite of some remaining difficulties, at present, full chiral recognition of the monosaccharides in the original polysaccharide, as well as the partially methylated sugars in a permethylated galactan is an absolute requisite for a fine structural study of red seaweed galactan structures. 

Ginsenan S-IIA, a polysaccharide fraction from the roots of P. ginseng is a potent inducer of IL-8 production by human monocytes and THP-1 cells, and this induction is accompanied by increased IL-8 mRNA expression. The polysaccharide appears from the structural feature to be a mixture of arabino-galactan type I and type II, based on the presence of 1,3-, 1,6-, 1,3,6-, 1,4-, and 1,4,6-galactose units as well as terminal arabinose and 1,5-, 1,3,5-, and 1,2,5-linked units. It also contains 1,4,6-linked glucose units that together with the 1,2,5-linked arabinose units are different from the units found in other ginseng polysaccharides and may thus be of importance for the activity [64]. 

The structure that appears to be important for the effect on the complement system is most probably the complex galactan ohgomer being composed of separate 1,3- and 1,6-hnked galactose chains with branch points being of 1,3,6 nature. These units have been proposed as the active sites for... 

Benzyl derivatives of (1 6)-a-D-glucan, (l->6)-a-D-mannan, and (l-> 6)-a-D-galactan have been studied in 1,4-dioxane. These derivatives have complex and interesting c.d. spectra due to the ww transition of the chromophore with resolved vibrational structure. However, a conformational interpretation of these interesting spectra is not possible at this time. 

In the present study the pentasaccharide fragment related to the backbone structure of rhamnogalacturonan I, together with its rudimentary galactan side-chain, has been subjected to further exhaustive modelling study using the MM3(92) [5] and CICADA protocols [6],... 

---