Inulin synthesis

More recently, the chemo-enzymatic synthesis of inulin-containing hydrogels was reported [54]. The key point was the solubility of inulin [a mixture of oligomers and polymers containing 2-60 (or more) 5-2,1 linked D-fructose molecules having a glucose unit as the initial residue] in dimethylformamide (DMF), a fact that allowed its esterification by action of a protease from Bacillus subtilis. 

The concepts thus obtained touch on the phenomenon of assimilation. Fischer wrote in 1890 Chemical synthesis leads... to optically inactive acrose. In contrast to this, only active sugars have so far been found in plants. No known fact contradicts the supposition that the plant produces. . . first the inactive sugars which it then resolves, and uses the members of the d-mannitol series to build up starch, cellulose, inulin, and the like, while using their optical isomers for other purposes, now unknown.. . . Since then, I have attempted in vain to find Z-glucose or... 

Furan-2,5-dicarboxylic add also has tremendous industrial potential, because it could replace oil-derived diadds such as adipic or terephthalic acid as monomers for polyesters and polyamides [98, 99]. This diadd can be synthesized by Pt-catalyzed oxidation with 02 of 5-hydroxymethylfurfural the latter is obtained by acid-catalyzed dehydration of D-frudose or frudosans (inulin) the latter, however, are too expensive as starting materials, and yields from glucose-based waste raw materials are no higher than 40%. Therefore, the potential attractive option of furan-2,5-dicarboxylic acid will develop only after an effident generation of 5-hydroxymethylfurfural from forestry waste materials has been developed. The same compound is also the starting material for the synthesis of other interesting chemicals obtained by oxidative processes, such as 5-hydroxymethylfuroic add, 5-formylfuran-2-carboxylic add and the 1,6-dialdehyde. 

This activation reaction was followed by means of proton NMR. This technique allowed us to monitor the concentrations of the monosuccinate groups, CDI, as well as the imidazol liberated during the reaction, As can be seen from Figure 2 the activation is quantitative and completed within 20 minutes. The CDI-activated inulin succinate (V) was subsequently coupled with the N-glycyl derivative of procainamide (VI), the synthesis of which was reported before (8) ... 

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. 

Kaeser, W., Ultrastructure of storage cells in Jerusalem artichoke tubers (Helianthus tuberosus L.) vesicle formation during inulin synthesis, Z. Pflanzenphysiol., Ill, 253-260, 1983. 

Yasuda, T., Yajima, Y., and Yamada, Y., Induction of DNA synthesis and callus formation from tuber tissue of Jerusalem artichoke by 2,4-dichlorophenoxyacetic acid, Plant Cell Physiol., 15, 321-329, 1974. Yeoman, M.M., Tissue Culture and Plant Science, Street, H.E., Ed., Blackwell s, Oxford, 1974, pp. 1-17. Zubr, J. and Pedersen, H.S., Characteristics of growth and development of different Jerusalem artichoke cultivars, in Inulin and Inulin-containing Crops, Fuchs, A., Ed., Elsevier, Amsterdam, The Netherlands, 1993, pp. 11-19. 

Succinic acid has a diverse range of applications in the synthesis of specialty chemicals used in agriculture, foods, medicine, textiles, plating, and waste-gas scrubbing (Winstrom, 1978). Currently, succinic acid is produced via the hydrogenation of maleic anhydride to succinic anhydride and hydration to succinic acid (Winstrom, 1978 Zeikus et al., 1995). The thermophylic anaerobic bacteria Clostridium thermosuccinogenes can convert inulin to succinate and acetate as major... 

D-Mannitol has a diverse range of industrial applications. It is a nonhydroscopic, low-calorie, noncariogenic sweetener utilized by the food industry as well as a feedstock for the synthesis of other compounds. For example, mannitol can be oxidized at the 3 or 4 position to form two molecules of glyceraldehyde or glyceric acid, which can be used as building blocks for other compounds (Heinen et al., 2001 Makkee et al., 1985 van Bekkum and Verraest, 1996). Mannitol is formed from inulin via hydrolysis followed by catalytic hydrogenation. This yields mannitol and sorbitol from which the mannitol can be readily crystallized (Fuchs, 1987). Currently mannitol is primarily synthesized from starch. 

FIGURE 5.6 Synthesis of inulin ethers, dialdehyde-inulin, inulin carbamates, and inulin coupled to amino acids. 

FIGURE 5.7 Synthesis of O-(cyanoethyl) inulin, 0-(3-amino-3-oxopropyl) inulin, O-(carboxyethyl) inulin, 0-(3-hydroxylimio-3-aminopropyl) inulin, O-(aminopropyl) inulin, steroyl amide inulin, IV-carboxymethyl(aminopropylated) inulin, l-oxo-9-tetrakia(carboxymethyl)-3,6,9-triazanoyl-3-aminopropyl inulin, and l,ll-dioxo-3,6,9-tris-(carboxymethyl)-3,6,9-triazaundecanedioyl-bis(3-aminopropyl) inulin. 

Inulin alkoxylates are reported to have surface-active, emulgating, and stabilizing properties. They may also be further altered via reaction with other epoxides. Initial synthesis methods utilized... 

Rogge, T.M. and Stevens, C.V., Facilitated synthesis of inulin esters by transesterification, Biomacromolecules, 5, 1799-1803, 2004. 

Vermeersch, J. and Schacht, E., Synthesis of succinoylated inulin and application as carrier for procainamide, Bull, des Soc. Chimiques Beiges, 94, 287-291, 1985. 

Verraest, D.L., da Silva, L.P., Peters, J.A., and van Bekkum, H., Synthesis of cyanoethyl inulin, aminopropyl inulin, and carboxyethyl inulin, Starch/Starke, 48, 191-195, 1996c. 

Vervoort, D., Van den Mooter, G., Augustijns, P., Busson, R., Toppet, S., and Kinget, R., Inulin hydrogels as carriers for colonic drug targeting. I. Synthesis and characterization of methacrylated inulin and hydrogel formation, Pharm. Res., 14, 1730-1737, 1997. 

Inulin biosynthesis in Jerusalem artichoke occurs via the combined action of two enzymes l-sucrose sucrose fructosyltransferase (1-SST) and l-fructan fructan fructosyltransferase (1-FFT). 1-SST catalyzes the synthesis of inulins of a low degree of polymerization, while 1-FFT catalyzes the synthesis of ffuctans of a degree of polymerization up to 50 (Sevenier et al., 2002a). High... 

Inulin synthesis in the tubers occurs in the vacuoles of storage parenchyma cells. Kaeser (1983) proposed a model for the transport of sucrose into the central vacuole that involves the formation of vesicles within the cytoplasm that contain sucrose and inulin synthesis enzymes. The vesicles transfer their contents into the vacuole via two possible mechanisms (1) the cytoplasmic vesicle fuses with the tonoplast and through pinocytosis releases its contents into the vacuole, or (2) vesicles originating from plasmalemma invaginations are tied off into the vacuole, resulting in... 

Carpita, N.C., Keller, F., Gibeaut, D.M., Housley, T.L., and Matile, P., Synthesis of inulin oligomers in tissue slices, protoplasts and intact vacuoles of Jerusalem artichoke, J. Plant Physiol., 138, 204-210, 1991. 

Leuscher, M., Erdin, C., Sprenger, N., Hochstrasser, U., Boiler, T., and Wiemken, A., Inulin synthesis by a combination of purified fructosyltransferases from tubers of Helianthus tuberosus, FEBS Lett., 385, 39-42, 1996. 

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