Production of larch [Larix] arabinogalactan, 2: Variation of arabinogalactan in stems of Siberian larch
1994
Mizumoto, K.(Toyama-ken. Agricultural, Forestry and Fisheries Research Center (Japan)) | Takahashi, R. | Tajika, K. | Takano, R.
On the wood of Larix species collected in Siberia and imported from Port Vanino, Primorskiy, Russia, variations of the content of the cold water extracts (named as crude arabinogalactan), the content of its composed polysaccharides, the neutral sugar composition, the amount of uronic acid and a total amount of phenol in stems were examined. Following subjects were clearly clarified by those results. 1) Contents of the crude arabinogalactan (arabinogalactan was abbreviated as AG hereafter) in heart woods was 10.5% and this value was extremely high as compared with 1.8% in sap woods. In addition, the sugar content in the crude AG was almost two times of that in sap woods. Furthermore, because the neutral sugar composition and the distribution of the molecular weight were monodispersal, it was presumed that other polysaccharides were very few in crude AG. 2) Content rates of the crude AG showed a tendency of increasing from the pith towards the intermediate wood, but the content rate was suddenly decreased in sap woods. Total sugar contents in the crude AG also showed the same variations as the crude AG. On the contrary, almost no differences in the total phenol were found in heart woods, but a total phenol clearly increased in sap woods. 3) The crude AG of high quality was accumulated densely in the periphery of heart woods on the inner part of intermediate woods and this part was possible as the most useful supplying part for AG raw materials.
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