Sucrose residues

The introduction of sugars into polymeric molecules can bestow new properties, such as increased polarity, chirality, and biodegradability or biocompatibility. Sucrose-containing polymers can be of various types, either having the carbohydrate backbone within the polymer chain or having pendant sucrose residues serving as functional polar groups. 

It was of interest to include in our biological tests a compound in which the sucrose residue was incorporated into an R group of an R SnX compound. To this end we utilised the series of reactions shown in Figure 3, beginning with the sodium salt of the crude sucrose phthalate. Given the complexity of the starting material, the final bromo compound, of course, is a mixture but its analysis, infra red (ir) and nmr spectra correspond to the formula shown. 

These results show that the tributyltin and triphenyltin derivatives of sucrose are at least equal in biological activity to the commercially used tributyltin oxide and fluoride and are superior with regard to algicidal and fungicidal properties (9, 10). This is even more remarkable when we compare the tin contents, see Table VII. Except in the case of molluscicidal activity the tricyclohexyltin compounds are less effective and, in most tests, the less accessible compound with the sucrose residue in the R groups is inferior. Tests on the orgeinolead compotands so far have been confined to molluscicidal activity. 

D-fructose, C HijOo. Crystallizes in large needles m.p. 102-104 C. The most eommon ketose sugar. Combined with glucose it occurs as sucrose and rafftnose mixed with glucose it is present in fruit juices, honey and other products inulin and levan are built of fructose residues only. In natural products it is always in the furanose form, but it crystallizes in the pyranose form. It is very soluble in... 

High test molasses is not a residual material, but cane juice, sometimes partly clarified, concentrated by evaporation, with at least half its sucrose hydrolyzed to invert (glucose and fmctose) by heating at the low juice pH (5.5). 

Conformation. Neutron diffraction studies of sucrose revealed the presence of two strong intramolecular hydrogen bonds 0-2—HO-1 and 0-5—HO-6 in the crystal form (7,8). These interactions hold the molecule in a weU-ordered and rigid conformation. The two rings are disposed at an angle close to 90°, with the glucopyranosyl and fmctofuranosyl residues adapting chair and T" twist conformations, respectively. 

Corn steep liquor contains 2.5% invert sugars and 50% water. The rest of the feed is considered as residual solids. Beet molasses containing 50% sucrose, 1% invert sugar, 18% water and remainder solids are mixed with corn steep liquor in a mixing tank. Water is added to produce a diluted mixture with 2% invert sugar, 125 kg com steep hquor and 45 kg molasses, which is fed into an enzymatic hydrolysis tank. 

The concentration of sucrose in the product mixture is x = 0.1259 or 12.59% of product. The residual solids in corn steep, molasses and the diluted mixture are also balanced. 

Optimum toxin production was found in a stirred, aerated culture medium consisting of potato infusion and sucrose after 3 to 5 days growth. The toxin was adsorbed on charcoal from the culture filtrate and eluted with chloroform. The red-brown residue remaining after evaporation showed little or no absorption in the carbonyl region of the infrared and only weak absorption in the ultraviolet. However, on mild treatment with acid, base, or heat two carbonyl peaks appeared at 1715 and 1685 cm.-1 in the infrared and at 266 mft in the ultraviolet (3). 

The treatment of sucrose with anhydrous HF89 results in the formation of a complex mixture of pseudooligo- and poly-saccharides up to dp 14, which were detected by fast-atom-bombardment mass spectrometry (FABMS). Some of the smaller products were isolated and identified by comparison with the known compounds prepared86 88 a-D-Fru/-1,2 2,1 -p-D-Fru/j (1), either free or variously glucosylated, was a major product, and this is in accord with the known stability of the compound. The mechanism of formation of the products in the case of sucrose involves preliminary condensation of two fructose residues. The resultant dianhydride is then glucosylated by glucopyranosyl cation.89 The characterization of this type of compound was an important step because it has permitted an increased understanding of the chemical nature of caramels. 

---