Methylated inulin

Butenediol Succinic acid Lactic acid Inulin esters O-Succinoylated inulin Methylated inulin Inulin carbonates 0-(Carboxymethyl)inulin Inulin ethers Dialdehyde inulin Inulin carbamates Inulin-amino acids 0-(Cyanoethyl)inulin... 

However, some carbohydrates with a terminal D-fructofuranose residue are not suitable substrates for levan formation, e. g., methyl /3-d-fructofuranoside and inulin,64 even in the presence of enzymes98 which hydrolyze these substrates. 

The specificity of levansucrase98 is dependent not only on the d-fructoside but also on the aldoside residue of the substrate. Neither inulin nor methyl D-fructofuranoside was hydrolyzed by levansucrase, and even when these two substrates were hydrolyzed by inulase (prepared from inulin-fermenting Torula yeast) or by yeast invertase respectively, no levan formation occurred with levansucrase. However, neither methyl D-fructofuranoside nor inulin inhibited levan formation from sucrose by levansucrase. No levan was formed from potassium D-glucose... 

Haworth, Hirst and Percival23 methylated inulin by first acetylating and subsequently converting the acetate to the methyl derivative by means of dimethyl sulfate and sodium hydroxide in acetone solution, a procedure described by Haworth and Streight.24 They hydrolyzed trimethylinulin and quantitatively determined the amounts of trimethyl-D-fructose and tetramethyl-D-fructose formed. There was obtained 3.7%... 

Inulin Acetate. Stir 100 g. of inulin in 1,000 ml. of pyridine at 80° for forty-five minutes. Cool, while continuing the stirring, and to the clear solution add dropwise 180 ml. of acetic anhydride. After six hours more of stirring, pour the clear solution into 10 liters of water. The inulin acetate separates as a white solid. Filter and wash repeatedly with distilled water to remove the pyridine and acetic anhydride. Purify the dried crude product by dissolving in ten times its weight of hot methyl alcohol and filtering. Inulin acetate separates from the cold solution as a fine white powder [ajj20 = — 34° (c = 1.5, chloroform), [o ]d20 = — 43° (c = 1.8, acetic acid). 

They prepared the acetate by means of acetic anhydride in dry pyridine and purified it by separation from an acetic acid solution to which warm methyl alcohol had been added n ]n2 = — 22.70° (c = 10, acetic acid), m. p. 206-208°. In the presence of barium hydroxide irisin formed an insoluble product whose composition was represented by 6(C6Hi0O6)-Ba(OH)2. In contrast to inulin, these authors found that Takadiastase at pH 5 to 5.5 did not hydrolyze irisin. 

Difructose anhydride II reacts with one mole of per-iodic acid. Hydrolysis of its methyl derivative indicates that two different trimethyl-D-fructoses are formed whose combined specific rotations in water amount to between + 20° and + 30°. If we assume that this anhydride, like the other two derived from inulin, is made up of D-fructofuranoses, the facts that have been mentioned allow only three possible structures for this anhydride. 

Inulin nitrate is insol in w, eth, ethyl and methyl ale, toluene and carbon tetrachloride, but dissolves in acetone, ether ale mixt, coned H2S04, ethyl acetate etc. It does not crystallize from solutions but forms a film... 

Codonopsis pilosula (Franch.) Nannfeldt C. tangshen Oliv. China Taraxeryl acetate, friedelin, n-butyl allophanate, inulin, sucrose, amino acids, stigmasterol, spinasterol, methyl palmitate, taraxerol.48 For amnesia, anorexia, asthma, cachexia, cancer, impotence, insomnia, palpitations. 

Liquid 1,3,4,6-tetramethyl-D-fructofuranose (XXII), [oi]d +29.3° in water, was first obtained by Haworth and Law11 as one of the hydrolysis products of octamethylsucrose. It was obtained in purer condition, [ ]D +31.7°, by Haworth127 from heptamethylsucrose and also by Irvine and Steele,128 [a]D +32.9°, from methylated inulin. It was pre-... 

Four trimethyl-D-fructoses are known but only one of them is crystalline. Crystalline 1,3,4-trimethyl-D-fructose has been obtained from methylated levan,10 1,4,6-trimethyl-D-fructose from methylated melezi-tose and by synthesis, 3,4,6-trimethyl-D-fructose from methylated inulin and by synthesis, and 3,4,6-trimethyl-D-fructose has been synthesized. 

The only dimethyl-D-fructose which has been characterized, 3,4-di-methyl-D-fructose, has been prepared by McDonald and Jackson141 from di-D-fructose anhydride I. Tritylation of this anhydride gives the 6,6 -ditrityl derivative which is methylated to 3,4,3, 4 -tetramethyl-6,6 -di-trityl-di-D-fructose anhydride I. Removal of the trityl groups followed by hydrolysis yields liquid 3,4-dimethyl-D-fructose, [ ]d —60.66° in water. It has also been obtained, with 4-methyl-D-fructose, from the hydrolysis of methylated di-D-fructose anhydride III. The structure of this dimethyl-D-fructose follows from its method of preparation from di-D-fructose anhydride I whose structure is known.10 McDonald and Jackson also prepared 3,4-dimethyl-D-fructose from inulin by the following method inulin — monotrityl inulin — monotrityl inulin diacetate — dimethyl monotrityl inulin — dimethyl isopropylidene-D-fructose — methyl dimethyl-D-fructoside —> 3,4-dimethyl-D-fructose. Its structure was confirmed by its oxidation without loss of methyl to the same lactol of the dimethyl dibasic acid obtained from 1,3,4-trimethyl-D-fructose (see page 78). The phenylosazone made from 3,4-dimethyl-D-fructose has m. p. 126° that from 3,4-dimethyl-D-glucose has not been recorded. 

Complete methylation of inulin (4) can be achieved by reaction with potassium hydroxide solution followed by the addition of dimethyl sulfate (Figure 5.5) (Irvine and Steele, 1920 Irvine and Montgomery, 1933 Irvine et al., 1922). Alternatively, complete methylation can be accomplished using methyl iodide and silver oxide (Karrer and Lang, 1921 Vaughn and Robbins 1975). Trimethyl inulin can be hydrolyzed to form 3,4,5-trimethylfructofuranose (Smeekens et al., 1996). 

Karrer, P. and Lang, L., Polysaccharides. V. Methylation of inulin, Helv. Chim. Acta, 4, 249-256, 1921. 

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