Analysis of mixtures of some mono-O-methylaldoses with the common aldoses by g.l.c.-m.s. after isopropylidenation
作者:Kai H. Aamlid、Svein Morgenlie
DOI:10.1016/0008-6215(83)88350-5
日期:1983.12
Abstract The O-isopropylidene derivatives of seven naturally occurring mono-O-methylaldoses have been characterised by g.l.c.-m.s. G.l.c. conditions have been found under which almost complete separation of the O-methyl sugars and the commonaldoses as their O-isopropylidene derivatives can be achieved. This analysis procedure has been applied to the hydrolysates of three polysaccharides that contain
Studies on the Chemical Constitution of Agar-agar. XXIII. Isolation of D-Xylose, 6-<i>O</i>-Methyl-D-galactose, 4-<i>O</i>-Methyl-L-galactose and<i>O</i>-Methylpentose
作者:Choji Araki、Kiyoshi Arai、Susumu Hirase
DOI:10.1246/bcsj.40.959
日期:1967.4
Commercial agar was subjected to complete hydrolysis with dilute sulfuric acid, and the products were carefully investigated. Besides D- and L-galactose, which have been known to exist, there were isolated small amounts of D-xylose, 6-O-methyl-D-galactose, 4-O-methyl-L-galactose, and O-methylpentose, all the sugars except the last one being obtained in crystalline forms. Among these products, 4-O-methyl-L-galactose
Selective Hydrolysis of the 3,6-Anhydrogalacotosidic Linkage in Red Algal Galactan: A Combination of Reductive Acid Hydrolysis and Anhydrous Mercaptolysis
Here we report a simple method for the structural analysis of red algal galactan containing 3,6-anhydrogalactose. Structural heterogeneity in the galactan was demonstrated by this method. For selective hydrolysis of 3,6-anhydrogalactosidic linkages in the galactan, conditions for reductive mild acid hydrolysis were examined by characterizing the resulting oligosaccharide alditols by anhydrous mercaptolysis. Residues other than alditols at the reducing ends, including labile 3,6-anhydrogalactose, were liberated quantitatively as diethyl dithioacetal derivatives, whereas alditols at the reducing ends were not derivatized and were liberated as alditols intact. The liberated sugars were then separated and measured quantitatively by gas-liquid chromatography. Heating of agarose in reductive hydrolysis with 0.3 m trifluoroacetic acid in the presence of an acid-stable reducing agent, 4-methyl morpholine borane, at 80 °C for 90 min and for 90 °C for 45 min was found to be optimum for the selective hydrolysis of 3,6-anhydrogalactosidic bonds, without detectable cleavage of other glycosidic bonds.
UTILISATION D'UN EXTRAIT OU D'UNE FRACTION D'EXTRAIT D'ALGUE ROUGE AGAROPHYTE COMME ÉLICITEUR/STIMULATEUR DE DÉFENSE VÉGÉTAL ET APPLICATION DUDIT EXTRAIT OU DE LADITE FRACTION D'EXTRAIT
申请人:Societe d'Etude et d'Exploitation d'Algues et
Produits Maritimes (SETEXAM)
公开号:EP3566580A1
公开(公告)日:2019-11-13
Utilisation comme éliciteur/stimulateur de défense chez les plantes terrestres d'un extrait ou d'une fraction d'extrait d'au moins une algue rouge agarophyte, ledit extrait ou ladite fraction d'extrait contenant au moins un oligosaccharide ayant de 2 à 50 unités ose liées entre elles de façon covalente, et des polysaccharides ayant plus de 50 unités ose liées entre elles de façon covalente pouvant être contenus sans dépasser 0,01% en poids par rapport aux oligosaccharides/ polysaccharides totaux.
在陆生植物中用作防御诱导剂/刺激剂的至少一种藻类红藻的提取物或提取物馏分,所述提取物或提取物馏分含有至少一种具有 2 至 50 个共价连接在一起的 Ose 单元的寡糖,以及具有 50 个以上共价连接在一起的 Ose 单元的多糖,其含量不超过寡糖/多糖总重量的 0.01%。