Higher Oligosaccharides Related to Sucrose

Sap availability in several European tree species has been investigated (77, 103). Sugar analysis of these saps revealed that sucrose was the only sugar present in sycamore maple (Acer pseudoplatanus) sap. Sucrose has also been extracted from slippery elm (Ulmus fulva) bark (51). 

Much less effort has been directed toward investigations of the oligosaccharides of woody plants than toward the oligosaccharides of nonwoody plants. Issues that need to be addressed are taxonomic distribution, compartmentation within the plant and within cells, function(s), seasonal variation, anabolism, catabolism, and regulatory mechanisms. However, some information is available. 

The trisaccharide raffinose (2) [0-a-D-galactopyranosyl-(l- 6)-a-D-glucopy-ranosyl-(l 2)-)ff-D-fructofuranose)] is the second most abundant oligosaccharide in the plant kingdom and, like sucrose, may be ubiquitous - i.e. it may yet be found in plants not known to contain it when all tissues are carefully analyzed at all stages of development and in all seasons. 

The tetrasaccharide stachyose (3) [a-galactopyranosyl-(l- )-a-D-galacto-pyranosyl-(l- 6)-a-D-glucopyranosyl-(l- 2)-)8-D-fructofuranose] seems to be almost as widely distributed as raffinose (98), but is present in even lower concentrations. Although raffinose and stachyose occur in all parts of plants, they are 

The next higher oligomer, verbascose (4), is generally found in trace amounts only in tissues in which raffinose accumulates to a high concentration. 

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