This study was performed to prepare immobilized β-glucosidase and snailase, then optimize and compare the process conditions for conversion of icariin. Immobilized β-glucosidase and snailase were prepared using crosslink-embedding method. The best conditions of the preparation process were optimized by single factor analysis and the properties of immobilized β-glucosidase and snailase were investigated. The reaction conditions including temperature, pH, substrate ratio, substrate concentration, reaction time and reusing times of the conversion of icariin using immobilized β-glucosidase or snailase were optimized. Immobilized β-glucosidase and snailase exhibited better heat stabilities and could remain about 60% activity after storage at 4 degrees C for 4 weeks. The optimized conditions for the conversion of icariin were as follows, the temperature of 50 degrees C, pH of 5.0, enzyme and substrate ratio of 1 : 1, substrate concentration of 0.1 mg x mL(-1), reaction time of 6 h for β-glucosidase and 2 h for snailase, respectively. In 5 experiments, the average conversion ratio of immobilized β-glucosidase and snailase was 70.76% and 74.97%. The results suggest an effect of promoted stabilities, prolonged lifetimes in both β-glucosidase and snailase after immobilization. The immobilized β-glucosidase and snailase exhibited a higher conversion rate and reusability compared to the free β-glucosidase and snailase. Moreover, the conversion rate of immobilized snailase was higher than that of immobilized β-glucosidase. The process of icariin conversion using immobilized β-glucosidase and snailase was moderate and feasible, which suggests that immobilized enzymes may hold a promise for industrial usage.
Enzymes, Immobilized ; chemistry ; Flavonoids ; chemistry ; Hydrolysis ; Temperature ; beta-Glucosidase ; chemistry

Scopoletin is a coumarin compound with various biological activities including detumescence and analgesic, insecticidal, antibacterial and acaricidal effects. However, interference with scopolin and other components often leads to difficulties in purification of scopoletin with low extraction rates from plant resource. In this paper, heterologous expression of the gene encoding β-glucosidase An-bgl3 derived from Aspergillus niger were carried out. The expression product was purified and characterized with further structure-activity relationship between it and β-glucosidase analyzed. Subsequently, its ability for transforming scopolin from plant extract was studied. The results showed that the specific activity of the purified β-glucosidase An-bgl3 was 15.22 IU/mg, the apparent molecular weight was about 120 kDa. The optimum reaction temperature and pH were 55 ℃ and 4.0, respectively. Moreover, 10 mmol/L metal ions Fe²⁺ and Mn²⁺ increased the enzyme activity by 1.74-fold and 1.20-fold, respectively. A 10 mmol/L solution containing Tween-20, Tween-80 and Triton X-100 all inhibited the enzyme activity by 30%. The enzyme showed affinity towards scopolin and tolerated 10% methanol and 10% ethanol solution, respectively. The enzyme specifically hydrolyzed scopolin into scopoletin from the extract of Erycibe obtusifolia Benth with a 47.8% increase of scopoletin. This demonstrated that the β-glucosidase An-bgl3 from A. niger shows specificity on scopolin with good activities, thus providing an alternative method for increasing the extraction efficiency of scopoletin from plant material.
Aspergillus niger/genetics* ; beta-Glucosidase/chemistry* ; Scopoletin ; Polysorbates ; Coumarins

The reaction conditions of baicalin hydrolyzed into baicalein by a kind of thermophilic and sugar-tolerant beta-glucosidase were studied in this paper. The beta-glucosidase could catalyze baicalin into baicalein well in the acetic acid-sodium acetate buffer. The optimal enzyme activity was at 85 degrees C and pH 5.5. The enzyme was stable at the temperature less than 85 degrees C and pH range of 5-7.5. The maximum reaction rate V. and michaelis constant K. were 0.41 mmol x L(-1) x min(-1) and 3.31 mmol x L(-1) respectively. Different metal ions had different effects on the activity of enzyme. Na+ existing in acetic acid-sodium acetate buffer had an activation effect on enzyme. The enzyme activity was enhanced by the concentrations of glucose below 0.6 mol x L(-1), and was gradually inhibited when monosaccharide concentration was over 0.6 mol x L(-1). When the monosaccharide concentration reached 1.2 mol x L(-1), the inhibition rate of enzyme activity was about 50%, which showed good glucose tolerance. The good reaction conditions through the experiment have been determined as follows, the substrate: enzyme dose was 1 g: 0.2 mL, acetic acid-sodium acetate buffer pH 5.5, reaction temperature 85 degrees C, reaction time 10 h, and the enzymatic hydrolyzation ratio could reach 97%.
Biocatalysis ; Enzyme Stability ; Flavanones ; chemistry ; Flavonoids ; chemistry ; Glucose ; chemistry ; Hot Temperature ; Hydrolysis ; Kinetics ; beta-Glucosidase ; chemistry

The optimum conditions of baicalin hydrolysis into baicalein by immobilized beta-glucosidase in a two-phase system was studied and the yield was observed. A two-phase system comprising of sodium acetate buffer and chloroform was determined by comparing the solubleness of baicalein in different solvents and partition coefficient of baicalein in related aqueous-organic two-phase system. beta-Glucosidase was immobilized by the crosslinking-embedding method using sodium alginate as the carrier The optimum reaction temperature, pH value, Michaelis constant, the thermal stability and pH stability were assayed. By comparing the yield of baicalin hydrolysis into baicalein by immobilized beta-glucosidase in two-phase system, the optimum reaction conditions were determined-the optimum reaction temperature, pH value and time were 50 degrees C, 5.0 and 10 h, respectively. The yield of baicalein was 85.28%. Compare with one-phase system, two-phase system had an advantage in reaction rate and yield.
Biocatalysis ; Drugs, Chinese Herbal ; chemistry ; Enzyme Stability ; Enzymes, Immobilized ; chemistry ; Flavanones ; chemistry ; Flavonoids ; chemistry ; Hydrolysis ; beta-Glucosidase ; chemistry

In order to explore the influence of reaction temperature on the product composition, the effect of continuous temperature change (22 degrees C-60 degrees C, +/-0.1 degree C) on hydrolysis of yeast beta-glucan by endo-beta-1,3-glucanase was determined by using self-developed Biochem-temperature Characteristic Apparatus. The activation energy of enzymatic hydrolysis of yeast beta-glucan was 84.17 kJ/mol. The optimum temperature represented by accumulation of products decreased exponentially within a certain period of time. The components of the products were changed with reaction temperature. The length of oligosaccharides decreased with the increase of temperature. The main products were laminaribiose and laminaritriose at the temperature higher than 46 degrees C, while the main products were laminaripentaose and larger molecular weight components at the temperature lower than 30 degrees C. The results can provide precise parameters to control the reaction temperature of the production of 1,3-beta-D-glucooligosaccharides.
Enzyme Activation ; Glucan Endo-1,3-beta-D-Glucosidase ; chemistry ; metabolism ; Hydrolysis ; Oligosaccharides ; chemistry ; metabolism ; Temperature ; Yeasts ; metabolism ; beta-Glucans ; metabolism

β-glucosidase has important applications in food, pharmaceutics, biomass conversion and other fields, exploring β-glucosidase with strong adaptability and excellent properties thus has received extensive interest. In this study, a novel glucosidase from the GH1 family derived from Cuniculiplasma divulgatum was cloned, expressed, and characterized, aiming to find a better β-glucosidase. The amino acid sequences of GH1 family glucosidase derived from C. divulgatum were obtained from the NCBI database, and a recombinant plasmid pET-30a(+)-CdBglA was constructed. The recombinant protein was induced to express in Escherichia coli BL21(DE3). The enzymatic properties of the purified CdBglA were studied. The molecular weight of the recombinant CdBglA was 56.0 kDa. The optimum pH and temperature were 5.5 and 55 ℃, respectively. The enzyme showed good pH stability, 92.33% of the initial activity could be retained when treated under pH 5.5-11.0 for 1 h. When pNPG was used as a substrate, the kinetic parameters K_m, V_max and K_cat/K_m were 0.81 mmol, 291.99 μmol/(mg·min), and 387.50 s^-1 mmol^-1, respectively. 90.33% of the initial enzyme activity could be retained when CdBglA was placed with various heavy metal ions at a final concentration of 5 mmol/L. The enzyme activity was increased by 28.67% under 15% ethanol solution, remained unchanged under 20% ethanol, and 43.68% of the enzyme activity could still be retained under 30% ethanol. The enzyme has an obvious activation effect at 0-1.5 mol/L NaCl and can tolerate 0.8 mol/L glucose. In conclusion, CdBglA is an acidic and mesophilic enzyme with broad pH stability and strong tolerance to most metal ions, organic solvents, NaCl and glucose. These characteristics may facilitate future theoretical research and industrial production.
beta-Glucosidase ; Sodium Chloride ; Temperature ; Glucose ; Ethanol/chemistry* ; Ions ; Hydrogen-Ion Concentration ; Enzyme Stability ; Substrate Specificity

Six new prenylated flavonoid glycosides, including four new furan-flavonoid glycosides wushepimedoside A-D (1-4) and two new prenyl flavonoid derivatives wushepimedoside E-F (5-6), and one know analog epimedkoreside B (7) were isolated from biotransformation products of the aerial parts of Epimedium wushanense. Their structures were elucidated according to comprehensive analysis of HR-MS and NMR spectroscopic data, and the absolute configurations were assigned using experimental and calculated electronic circular dichroism (ECD) data. The regulatory activity of compounds 1-7 on the production of testosterone in primary rat Leydig cells were investigated, and 4 and 5 exhibited testosterone production-promoting activities. Molecular docking analysis suggested that bioactive compounds 4 and 5 showed the stable binding with 3β-HSD and 4 also had good affinity with Cyp17A1, which suggested that these compounds may regulate testosterone production through stimulating the expression of the above two key proteins.
Animals ; Epimedium/chemistry* ; Flavonoids/chemistry* ; Furans ; Glycosides/chemistry* ; Hydrolysis ; Male ; Molecular Docking Simulation ; Molecular Structure ; Rats ; Testosterone ; beta-Glucosidase/metabolism*

Using Trichoderma as an indicative fungus, three antifungal proteins in Triticale Zhongsi 237 seed were purified and characterized. These protein components were considered to be a new Class II chitinase and two kinds of beta-1, 3-glucanases. Chitinase molecular mass was 30.5 kD and enzyme activity was maximal at pH 6.0 and 37 degrees C. Two beta-glucanases molecular masses were 51 kD and 23 kD. N-terminal amino acid sequences of Triticale chitinase share high homology with barley chitinase. In some conditions, the chitinase and beta-glucanases all had strong antifungal activity and were able to inhibit Trichoderma growth synergistically. Moreover, the chitinase and beta-1, 3-glucanases were able to inhibit powdery mildew growth on detached susceptible wheat leaves.
Antifungal Agents ; isolation & purification ; pharmacology ; Chitinases ; isolation & purification ; pharmacology ; Glucan 1,3-beta-Glucosidase ; Molecular Weight ; Plant Proteins ; isolation & purification ; pharmacology ; Seeds ; chemistry ; Trichoderma ; drug effects ; Triticum ; chemistry ; microbiology ; beta-Glucosidase ; isolation & purification ; pharmacology

This study aims to observe different factors which affected the bionic enzymatic hydrolysis of icariin into baohuoside I and to optimize the reaction conditions in order to provide research foundation for building a novel bionic enzymolysis drug delivery system. To simulate the environment in vivo, 37 degrees C was set as the temperature and artificial intestinal juice and gastric juice were selected as the buffer solutions. Taking the conversion of baohuoside I as index, the effects of the kinds of enzyme, enzyme activity, substrate concentration, reaction time, pancreatin in artificial intestinal juice and surfactant on the conversion of baohuoside I were investigated. The results showed that cellulase, beta-glucosidase and snailase were all inactive in artificial gastric juice and no baohuoside I generated. Pancreatin in artificial intestinal juice couldn't significantly influence the activity of beta-glucosidase or snailase (P > 0.05), but noticeably decrease the activity of cellulase (P < 0.05). In artificial intestinal juice, the conversion of baohuoside I was highest by using beta-glucosidase, and the optimum reaction conditions were determined as follows: enzyme activity 10 U x mL(-1), substrate concentration 1 mg x mL(-1), 3 g x L(-1) rhamnolipid and reaction time 3 h. Under this condition, the conversion of baohuoside I was 99.8%.
Animals ; Cellulase ; chemistry ; Flavonoids ; biosynthesis ; metabolism ; Hydrolases ; chemistry ; isolation & purification ; Hydrolysis ; Pancreatin ; chemistry ; Snails ; enzymology ; Surface-Active Agents ; chemistry ; beta-Glucosidase ; chemistry

Cellulosic material is the most abundant renewable carbon source in the world. Cellulose may be hydrolyzed using cellulase to produce glucose, which can be used for production of ethanol, organic acids, and other chemicals. Cellulase is a complex enzyme containing endoglucanase (EC 3.2.1.4), exoglucanase (EC 3.2.1.91) and cellobiase (EC 3.2.1.21). The hydrolysis of natural cellulose to glucose depends on the synergism of these three components. The mostly used cellulase produced by Trichoderma reesei has high activity of endoglucanase and exoglucanase, but the activity of cellobiase is relatively low. Therefore, improving the activity of cellobiase in cellulase reaction system is the key to enhance the sacchrification yield of cellulosic resources. Aspergillus niger LORRE 012 was a high productivity strain for cellobiase production. It was found that the spores of this strain were rich in cellobiase. In this work, the cellobiase was immobilized efficiently by simply entrapping the spores into calcium alginate gels instead of immobilizing the pure cellobiase proteins. The immobilized cellobiase was quite stable, and its half-life was 38 days under pH 4.8, 50 degrees C. The thermal stability of the immobilized cellobiase was improved, and it was stable below 70 degrees C. The suitable pH range of the immobilized cellobiase was pH 3.0 - 5.0, with the optimal pH value 4.8. The Km and Vmax value of the immobilized cellobiase were 6.01 mmol/L and 7.06 mmol/min x L, respectively. In repeated batch hydrolysis processes, 50 mL of substrate (10 g/L cellobiose) and 10 mL of immobilized beads containing cellobiase were added into a 150 ml flask. After reacting at pH 4.8, 50 degrees C for several hours, the hydrolysate was harvested for assay, and the immobilized beads were used for the next batch hydrolysis with the fresh substrate. This process was repeated, and the yield of enzymatic hydrolysis kept higher than 97% during 10 batches. The continuous hydrolysis process was carried out in a column reactor (inside diameter 2.8 cm, inside height 40 cm) packed with the immobilized beads. Using 10 g/L cellobiose as substrate, the hydrolysis yield reached 98% under 0.4 h (-1) dilution rate and pH 4.8, 50 degrees C. After corncob was treated by 1% dilute acid, the cellulosic residue (100 g/L) was used as substrate, and hydrolyzed by the cellulase (15 IFPU/g substrate) from Trichoderma reesei, at pH 4.8, 50 degrees C for 48 h. The concentration of reducing sugar in the hydrolysate was only 48.50 g/L (hydrolysis yield 69.5%). When the hydrolysate was further treated by the immobilized cellobiase, the cellobiose was hydrolyzed into glucose, and the feedback inhibition caused by the cellobiose accumulation disappeared sharply. By the synergism of immobilized cellobiase and the cellulase from T. reesei left in the hydrolysate, other oligosaccharides were mostly converted to monosaccharides. At 48 h, the reducing sugar concentration was increased to 58.78 g/L, the hydrolysis yield of the corncob residue was improved to 84.2%, and the ratio of the glucose in the total reducing sugar was increased from 53.6% to 89.5%. The reducing sugars converted from corncob could be used further in the fermentation of valuable industrial products. This research results were meaningful in the conversion and utilization of renewable biomass.
Aspergillus niger ; enzymology ; Biotechnology ; Cellobiose ; metabolism ; Enzyme Stability ; Hydrogen-Ion Concentration ; Kinetics ; Temperature ; beta-Glucosidase ; chemistry ; metabolism