Hemicelluloses and Other Plant Polysaccharides

A variety of polysaccharides with less common structure, although they contain mainly D-glucopyranosyl (glucans) or fructofuranosyl (fructans) groups, were isolated from plants [62]. Some of these are indicated in Table 7.7.1. 

Iceland moss, cereal grains Aspergillus niger, Iceland moss Lichens 

Dandelions, dahlias Various grasses Plants and bacteria 

Several Py-MS studies were done on homoglycans. A Py-FI MS study on a (1- 4)-p-xylan [2] showed several characteristic ions such as m/z = 132 (associated with the monomer unit C5H8O4), the ion m/z = 96 (associated with furfural, C5H4O2), and the ion m/z = 114 (probably associated with 3-hydroxy-2-penteno-1,5-lactone, CsHsOs). The study showed that retro-aldolization between C-1 and C-2 atoms does not take place. Smaller ions seen in the spectrum were probably generated from further pyrolysis of the initially formed fragments. 

6-dimethoxy-3-chloro-4-(1-hydroxy-prop-2-enyl)phenol A L 

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