Fructose phenylboronic acid

A long-wavelength probe 29 signaling carbohydrates in aqueous solutions by increasing of fluorescence was developed by Akkaya and Kukre on the basis of a symmetrical squaraine dye containing two phenylboronic acid functions [89]. The emission maximum of this probe is at 645 nm. A maximal response of about 25% was found for fructose. 

D-fructose (4370 M"1) > D-galactose (276 M"1) > D-glucose (110 M"1). From these results, it was confirmed that the PMBV/PVA hydrogel was formed under biological conditions, and that the reversible properties of the hydrogel corresponded to the formation of a complex between the phenylboronic acid group in PMBV and the diol moiety in PVA. 

Zenkl et al. [51] presented another approach to design saccharide-sensitive nanobeads. They prepared particles (0 380 nm) based on poly (/V- i sopropy I aery I am ide) cross-linked with phenylboronic acid moieties. In the presence of a saccharide (glucose or fructose) the particles reversibly swell due to the formation of negative charges. A FRET-indicator couple (fhiorescein/rhodamine) is used to monitor the... 

On addition of fructose, the apparent p Ka value decreases, leading to the remaining four curves shown in Figure 3.21. The explanation for this observation lies in the fact that the fructose complex of 16 is a stronger acid than is 16 itself. This result was predicated on the work of Edwards, who reported the same trend in polyol complexes of phenylboronic acid in 1959.(23) As determined in the presence of a near-saturating amount of fructose (100 mM), the apparent pKa of the fructose-16 complex is 5.9. The... 

Figure 11.3 Reactive DESI. (a) Reaction of phenylboronic acid with cis-diols. n = 1 or 2. Reactive-DESI mass spectra showing the ionic species generated from PhB(OH) anions upon interaction with (bj a blank surface, (c) D-fructose on the surface, and (d) D-glucose absorbed in a cotton tip [44], Reproduced from Chen, H., Cotte-Rodrfguez, I., Cooks, R.C. (2006) with permission of the Royal Society of Chemistry...

A study of the stability of compounds derived from D-glucose and D-fructose with boric acid or phenylboronic acid has found that the stability constants for the fructose compounds are much greater than those for the glucose compounds. The synthesis of crystalline 3-0-acetyl-2,4-0-phenylboranediyl- -D-ribopyranosyl bromide in a two pot process from D-ribose has been described along with some of its selective glycosylation reactions. Ethyl (dimethoxy)borane has been used in the synthesis of anomerically pure furanosides from the free sugars. Thus methyl 2,3-0-ethylboranediyl-tt-D-lyxofuranoside was prepared and then de-esterified under essentially neutral conditions to the glycoside in 80%... 

We also revealed that when phenylboronic acid is introduced to the secondary hydroxyl sites of y-CD (receptor 6), the complex of receptor 6 with fluorescent sensor 4 exhibits glucose selectivity in water due to multi-point interaction (Figure 13.7b). Fluorescent sensor 4, when used alone, is a selective fructose sensor. As illustrated by these examples, supramolecular CD complexes have great appeal in that the... 

Considering Scheme 7 we define the formation of the diol boronate anion complex as Aitet and the formation of the diol boronic acid complex as ATtrig, where it is observed that ATtet > ATtrig. For instance, the logarithm of these constants for phenylboronic acid binding fructose in 0.5 M NaCl water is log ATtet=3.8 whereas log ATtrig < 1.4. This difference in the value of the binding... 

In the presence of phenylboronic or butylboronic acid, lipase-catalysed esterifications of sugars can be carried out in hexane. This method has been applied to the anomeric monoacetylation of fructose with stearic acid. ... 

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