Enzymatic glucosidases

HPLC has been used to determine the levels of genistein, daidzein, biochanin A, formononetin, and equol in foods, formulas, and drinks consumed in Australia. Samples are diluted with water (1 10, v/v), hydrolyzed enzymatically (glucosidase 0.4 x/mL, 24 h at 37°C), and the aglycone form extracted in absolute ethanol, filtered and injected onto the HPLC. The lower limits of detection with this procedure for daidzein, genistein, and equol are 54, 48, and 94 ng/mL, respectively, within batch precision of 0.7%-3.0% CV (Knight et al., 1998). 

Synthesis of naturally occurring (J-D-glucopyranosides based on enzymatic P-glucosidation using -glucosidase from almond... 

The Shen group has devised a domino process wherein after an enzymatic cleavage of a glycoside a rearrangement sequence takes place [18]. Subjecting multifloroside 8-38 to P-glucosidase in acetate buffer (Scheme 8.10) afforded jasmolac-tone analogues such as 8-39 in a rather low yield. 

The authors conducted preliminary biological investigation on these complexes, studying their stability toward enzymatic hydrolysis. Interestingly, the glucoside residue was not released from the complexes under the action almond /j-glucosidase,... 

Thioglycosylated derivatives has been shown to resist to the enzymatic hydrolysis of the (3-thioglucosydic bonds by p-glucosidases. 

During the past year, several new studies have been published on -D-glucosidase IME systems that attempt to fulfill these process-relevant criteria. Immobilization of -D-glucosidase by attachment to polyurethane foam (40) has shown some promise as an economical IME system due to the support s resistance to enzymatic and microbial degradation, advantageous physical properties, and improved kinetics. However, the potential for fouling by particulate matter exhibited by foams renders these supports... 

G. Legler, Action mechanism of glucosidase-splitting enzymes. II. Isolation and enzymatic properties of two 3-glucosidases from Aspergillus wentii, Hoppe Seyler s Zeitschr. Physiol. Chem., 348 (1967) 1359-1366. 

T. Mega and Y. Matsushima, Energy of binding of Aspergillus oryzae p-glucosidase with the substrate, and the mechanism of its enzymatic action, J. Biochem., 94 (1983) 1637-1647. 

T. B. Frandsen, F. Lok, E. Mirgorodskaya, P. Roepstorff, and B. Svensson, Purification, enzymatic characterisation and nucleotide sequence of a high-isoelectric-point a-glucosidase from barley malt, Plant Physiol., 123 (2000) 275-286. 

Homogenization with NaOAc solution at 100°C for lOmin Enzymatic digestion with acid phosphatase, papain, amylase, glucosidase with addition of glyoxylic acid, ferrous sulfate solution and Gh at 37°C for 18h centrifugation ... 

Acid hydrolysis with HCl at 121°C for 30min (5 min for vegetables) enzymatic digestion with acid phosphatase (and glucosidase for vegetables) addition of HCl centrifugation filtration... 

The pretreatment of wastewater with hydrolases or acids is one of the best ways to overcome this obstacle, because in this way the big polymer molecules can be decomposed to smaller units, which can be measured by the biosensor. The positive effect of an enzymatic pretreatment of wastewater prior to sensorBOD measurement was demonstrated [53, 66]. In these investigations, different types of wastewaters, which contained milk powder, starch, or cellulose, were treated by proteases, a-amylases, and cellulases or a mix of these enzymes, respectively. This pretreatment resulted in a good correlation between sensorBOD and the conventional five-day BOD, while the sensorBOD values for untreated wastewater were significantly lower (see Table 6). As an example, the sensorBOD of a wastewater from a paper factory increased approximately to the fourfold value when treated by a mixture of cellulase and -glucosidase. 

Raspberry ketone [4-(4 -hydroxyphenyl)-butan-2-one], the impact compound found in raspberries, can be obtained by enzymatic reactions The first step is the /i-glucosidase-catalysed hydrolysis of the naturally occurring betu-loside to betuligenol. The latter can be transformed into raspberry ketone by microbial alcohol dehydrogenase (Scheme 22.2) [56]. 

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