Spruce, black, hemicellulose

Deoxy-3-0-methyl-L-mannose (3-O-methyl-L-rhamnose) HO HO H H HsC—C—C C—C—CHO H H MeO HO black-spruce hemicellulose Strophanthus sp. 

The Hemicelluloses of Scots Pine (Pinus sylvestris) and Black Spruce (Picea nigra) Woods, A. R. N. Gorrod and J. K. N. Jones,/. Chem. Soc., (1954) 2522-2525. 

A recent study of black spruce using FT-Raman with Nd YAG laser excitation (1,064 nm) proved successful (11). The goal in these studies was to be able to assign Raman features to the constituents of black spruce, cellulose, lignin, and hemicellulose. Black spruce is a soft wood. Any results obtainable could be applicable to all soft woods, and since soft woods are similar to hardwoods, the Raman bands observed could be assigned to cellulose and lignin. Hemicellulose contributions were not assignable because they were hidden under the cellulose bands. 

Tritiated Water. Exchange with tritiated water and subsequent scintillation analysis of the tritium content is a very useful method for accessibility measurements when the samples are not transparent to IR and visible light. Thin shives of sapwood from black spruce (a common softwood), and white birch (a common hardwood) where studied before and after delignification by treatment with peracetic acid (17). Also wood cambium from the same softwood was studied. The cambium is the recently formed fiber layer, located close to the bark and not yet lignified. Spruce and birch wood contain about the same amounts of cellulose, 42 and 44%, respectively. Spruce wood has more lignin (28 vs. 18% ), while birch has more hemicellulose (35 vs. 2S% ), in particular more pentosans than spruce (24 vs. 14%). 

The major D-galactan hemicellulose is an arabinogalactan obtained from softwoods such as larch, black spruce, pine, Douglas fir, cedar, and juniper [72]. Western larch is high in arabinogalactan. The larch arabinogalactans have main chains of D-galactopyranosyl units linked P-1 3 with branch chains of... 

---