Kestoses

Fig. 1 (A) Chromatographic separation of sugars. Track 1 fructose, 2 sucrose, 3 glucose, 4 mixture of the substances in tracks 1-3, 5 mixture of substances in tracks 1-3 and 6, 6 Fructo-oligosaccharides, 7 1-kestose, 8 mixture of glucose, maltose, maltotriose and maltotetraose. (B) Absorption scan of track 5 with 200 ng each substance per chromatogram zone 1 = fructosyl-nystose, 2 = nystose, 3 = 1-kestose, 4 = fructose, 5 = sucrose, 6 = glucose.

Kaempferol glucoside la 323 Kedde s reagent lb 236,237 1 -Kestose lb 423,424 6-Kestose lb 423 Ketazon lb 280 Keto acids la 262 a-Keto acids la 249,262,372 -, quinoxalone derivatives lb 343... 

NBP reagent la 90, 359 Neatan perservation la 134 Neoamygdalline lb 121 Neo-kestose lb 423 Neomycin la 287,423 Neostigmine lb 290 Nephopam la 45 Nerol la 76,327 -, glucoside la 327 Netilmicin la 105,286,287 Nettle leaf extract lb 217 Neuroleptics lb 352 Nickel-DMSO complex lb 259 Nickel cations la 144,145,311 lb 259-260... 

Ci8H32016 0-/ -D-Fructofuranosyl-(2— l)-0-/ -D-fructofuranosyl a-D-glu-copyranoside (1-kestose) KESTOS 30 32 455 370... 

Moreover, in further studies, a genetically optimized strain of A. niger with an overexpressed /i-fructofuranosidase transformed sucrose analogues efficiently and with high yield into the 1-kestose and 1-nystose analogues functionalized with different monosaccharides of potential interest (Fig. 8).115... 

Fig. 8. Different products with sucrose analogues as substrates.115 Enzymatic synthesis of 1-kestose, 1-nystose, and their analogues by /(-fructofuranosidase of A. niger. Structures of fructo-oligosaccharides (A) commercial products, (B) mannose- (C) galactose-, and (D) xylose-substituted analogues.

M. Korakli, M. Pavlovic, M. G. Ganzle, and R. F. Vogel, Exopolysaccharide and kestose production by Lactobacillus sanfranciscensis LTH2590, Appl. Environ. Microbiol., 69 (2003) 2073-2079. 

The decomposition of 1-kestose is a key step in the production of fructo-oligosaccharides, which are found in many health foods because of their noncaloric and noncariogenic nature. 

Duan et al. (1994) studied the decomposition of 1-kestose (S) using /3-fructosfuranosidase (E), both in the presence and absence of the competitive inhibitor glucose (G). 

Smythe (72) observed that the trisaccharide 1-kestose (7a), which bears an additional fructose moiety bound to Cl, binds at the —b pole of the crystal of sucrose. This result implies an extended antiplanar conformation (7b) of the group Cl -C-O-C(fiructose) such that the O-C(fructose) bond (filled circles in 7b) of the additive would point toward - b, away from the crystal interior. Note that, as in the sucrose-raffinose system, the Cl -C-O-H group of sucrose 5b (filled circles) adopts a gauche conformation with the C-OH bond pointing in the +b direction. It is gratifying that the necessary extended conformation of Cl -C-O-C was later demonstrated in an X-ray crystallographic study of 1-kestose 7b (74). 

Kestoses and nystose, Fermentation-derived sugar acids, Ascorbic acid-2-phosphates, Sugar phosphates, Inositol phosphates ... 

M. Verhaest, W. Lammens, K. Le Roy, C. J. De Ranter, A. Van Laere, A. Rabijns, and W. Van den Ende, Insights into the fine architecture of the active site of chicory fructan 1-exohydrolase 1-Kestose as substrate vs sucrose as inhibitor, New Phytol., 174 (2007) 90-100. 

Patterson, J.A., Orban, J.I., Sutton, A.L. and Richards, G.N. (1997) Selective enrichment of Bifidobacteria in the intestinal tract of broilers by thermally produced kestoses and effect on broiler performance. Poultry Science 68,1351-1356. 

Electron diffraction assessments of single crystals from inulin fractions indicate two antiparallel six-fold helices (Andre et al., 1996) a five-fold model has also been proposed (Marchessault et al., 1980). The hemihydrate molecule contains one water molecule for each two fructosyl units, while the monohydrate has one water molecule per fructosyl unit. When intermolecular hydrogen bonds are present, however, there is no evidence of intramolecular hydrogen bonding in the crystals. Crystal structures of 1-kestose (GF2) (Jeffrey and Park, 1972), nystose (GF3) (Jeffrey and Huang, 1993), and cycloinulohexaose (cF6) (Sawada et al., 1990) have been reported. 

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