Isomaltose gentiobiose

Similar acid-catalyzed oligomerization of methyl e<-D-glucopyranoside lead to the methyl glycosides of isomaltose, gentiobiose, cellobiose,... 

Extruded starches are easily dispersible, better soluble, and have a lower viscosity. The partial degradation of appropriately heated amylose shows that chemical changes also occur at temperatures of 185-200 °C. Apart from maltose, isomaltose, gentiobiose, sophorose, and 1,6-anhydroglucopyranose appeared. 

Fourteen DFAs and some oligomers were identified in caramel obtained by thermal treatment of inufin. - Monosaccharides (glucose, fructose), dehydration products (1,6-anhydro-p-D-glucopyranose, 1,6-anhydro-p-D-glucofuranose), disaccharides (gentiobiose and isomaltose), and oligosaccharides were also found in glucose and sucrose caramel. ... 

Disaccharides cellobiose and cellobiulose, (gentiobiose, isomaltose, kojibiose, laminarabiose, leucrose, melibiose, nigerose, palatinose, sophorose, trehalose, turanose, and xylobiose), lactose and lactulose, maltose and maltulose ... 

The diaacebaride was named isomaltose by Fischer.4 Later studies showed4 that the disaccharide was more likely to have been gentiobiose, not isomaltose. 

Curiously, among those C/O-disaccharide pairs that have been studied by X-ray, the gentiobiose, isomaltose, and sucrose pairs each show completely different conformational behavior in the solid state. C-Lactose bound to peanut agglutinin11 has been studied, and this case will be treated later. 

Comparison Between the Experimental J Values (Hz) Described tor the Glycosidic Torsion of a Series of /3-Gentiobiose (6) and a-Isomaltose (43), (1 — 6)-Llnked C-Glycosyl Compounds, and the Expected J Values (Hz) Given in Thble I... 

Glucose/com syrups may be manufactured by either an acid or an acid-enzyme process. Acid-catalyzed hydrolysis was the traditional method of corn syrup production and is still the most common method for producing sweeteners up to about 42 DE. Since acid-catalyzed hydrolysis of sweeteners to 55 DE or above creates products of reversion, such as gentiobiose, isomaltose and trehalose, which give unacceptable flavors to the syrup, these syrups are usually made by acid-enzyme processes.18... 

The pea lectin binds a-D-Iinked D-glucobioses, but not /3-D-linked disaccharides (except for gentiobiose, which has one-eleventh the inhibitory effect of isomaltose). Like con A, it interacts with 2-0-(2-acetamido-2-deoxy-/3-D-gIucopyranosyI)-D-mannose, suggesting that it may be capable of binding to glycoproteins containing internal 2-0-substituted a-D-mannopyranosyl residues.210... 

During acid hydrolysis, 5 to 6 percent of glucose undergoes side reactions to produce reversion products. These are predominantly isomaltose and gentiobiose, and, in addition, other di- and trisaccharides. 

Fig. 3-25. Gradient elution of different sugar alcohols and saccharides. - Separator column Ion Pac AS6A eluent (A) water, (B) 0.05 mol/L NaOH + 0.0015 mol/L acetic acid gradient 7% B isocratically for 15 min, then to 100% B in 10 min flow rate 0.8 mL/min detection pulsed ampero-metry on a Au working electrode (post-column addition of NaOH) injection volume 50 pL solute concentrations 15 ppm inositol (1), 40 ppm sorbitol (2), 25 ppm fucose (3), deoxyribose (4), 20 ppm deoxyglucose (5), 25 ppm arabinose (6), rhamnose (7), galactose (8), glucose (9), xylose (10), mannose (11), fructose (12), melibiose (13), isomaltose (14), gentiobiose (15), cellobiose (16), 50 ppm turanose (17), and maltose (18).

Figure 88. Partial MIKE/CAD spectra of (M + NH4) ions produced from a- and -cellobiose, a- and -maltose, a- and -isomaltose, ot- and -gentiobiose (in CI/NH4) [236].

Figure 89. Partial MIKE/CAD spectra [M + HN(CH3)j] ions produced from

By analogy with maltose and isomaltose, altemansucrase from Leuconostoc mesenteroides NRRL B-21297 was found to synthesize from gentiobiose as acceptor a series of gentiooligosaccharides that could be used as potential prebiotics, without the bitterness imparted by gentiobiose [86]. Altemansucrase also catalyzes... 

Additional work in 1987 centered around studies of the preferred conformations of various C-disaccharides. Preliminary work by Kishi, era/.,13 was subsequently confirmed by the same group in 1991.14 In these reports, utilizing C-glycosidic analogs of isomaltose and gentiobiose (Figure 8.5.1), it was determined that conformations of C-disaccharides can be predicted on the basis of steric interactions alone. This conclusion, based, in part, on similarities regarding the conformations and behaviors of conventional disaccharides in variable temperature proton NMR studies, was later extended to the conformations of C-trisaccharides introduced in Chapter 1. 

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