scholarly journals Evaluation of Enzyme Inhibitory Activity of Flavonoids by Polydopamine-Modified Hollow Fiber-Immobilized Xanthine Oxidase

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3931
Author(s):  
Cong-Peng Zhao ◽  
Guo-Ying Chen ◽  
Yuan Wang ◽  
Hua Chen ◽  
Jia-Wen Yu ◽  
...  

In this study, a polydopamine (PDA)-modified hollow fiber-immobilized xanthine oxidase (XOD) was prepared for screening potential XOD inhibitors from flavonoids. Several parameters for the preparation of PDA-modified hollow fiber-immobilized XOD, including the dopamine concentration, modification time, XOD concentration and immobilization time, were optimized. The results show that the optimal conditions for immobilized XOD activity were a dopamine concentration of 2.0 mg/mL in 10.0 mM Tris-HCl buffer (pH 8.5), a modification time of 3.0 h, an XOD concentration of 1000 μg/mL in 10.0 mM phosphate buffer (pH 7.5) and an immobilization time of 3.0 h. Subsequently, the enzymatic reaction conditions such as the pH value and temperature were investigated, and the enzyme kinetics and inhibition parameters were determined. The results indicate that the optimal pH value (7.5) and temperature (37 °C) of the PDA-modified hollow fiber-immobilized XOD were consistent with the free enzyme. Moreover, the PDA-modified hollow fiber-immobilized XOD could still maintain above 50% of its initial immobilized enzyme activity after seven consecutive cycles. The Michaelis–Menten constant (Km) and the half-maximal inhibitory concentration (IC50) of allopurinol on the immobilized XOD were determined as 0.25 mM and 23.2 μM, respectively. Furthermore, the PDA-modified hollow fiber-immobilized XOD was successfully applied to evaluate the inhibitory activity of eight flavonoids. Quercetin, apigenin, puerarin and epigallocatechin showed a good inhibition effect, and their percentages of inhibition were (79.86 ± 3.50)%, (80.98 ± 0.64)%, (61.15 ± 6.26)% and (54.92 ± 0.41)%, respectively. Finally, molecular docking analysis further verified that these four active compounds could bind to the amino acid residues in the XOD active site. In summary, the PDA-modified hollow fiber-immobilized XOD is an efficient method for the primary screening of XOD inhibitors from natural products.

2018 ◽  
Vol 80 (3) ◽  
Author(s):  
Suhaily Suhaimi ◽  
Rohaida Che Man ◽  
Natassha Jamil ◽  
Zatul Iffah Mohd Arshad ◽  
Shalyda Md Shaarani ◽  
...  

The production of cyclodextrin (CD) over the years has been increasing due to the numerous applications in industries such as in food, cosmetic, pharmaceutical and agricultural industries. However, cyclodextrin glucanotransferase (CGTase) which involved in the enzymatic reaction on the production of CD is unstable and easily denatured at extreme conditions resulted in low CD production. Hence, the enzyme immobilization technique is introduced to overcome these problems and subsequently increase the production of CD. In the present study, the CGTase was immobilized on hollow fiber membrane to increase the production of CD during the reaction. The effect of reaction conditions (types of starch, concentration of starch, temperature and pH) of the immobilized enzyme on the production of CD were investigated. Among the three types of starch tested, the soluble potato starch was the most suitable substrate for the production of CD with 4.13 mg/mL. In addition, by using 3% (w/v) of the soluble potato starch, the production of CD was 5.22 mg/mL . The optimal reaction temperature and pH were found to be at 40°C and pH 6 with 5.21 mg/mL and 4.62 mg/ml of CD, respectively. The immobilized enzyme exhibited a 1.3-3-fold increase in CD production compared to the free enzyme. Therefore, the hollow fiber membrane is suitable to be used as a support for enzyme immobilization with the high production of CD.


Planta Medica ◽  
2013 ◽  
Vol 79 (13) ◽  
Author(s):  
A Ványolós ◽  
O Orbán-Gyapai ◽  
T Támadi ◽  
J Hohmann

Planta Medica ◽  
2015 ◽  
Vol 81 (16) ◽  
Author(s):  
O Roza ◽  
A Martins ◽  
J Hohmann ◽  
WC Lai ◽  
FR Chang ◽  
...  

2021 ◽  
Vol 22 (11) ◽  
pp. 5482
Author(s):  
Zuo-Peng Zhang ◽  
Ye Zhong ◽  
Zhen-Bin Han ◽  
Lin Zhou ◽  
Hua-Sheng Su ◽  
...  

A series of saccharide-modified thiadiazole sulfonamide derivatives has been designed and synthesized by the “tail approach” and evaluated for inhibitory activity against carbonic anhydrases II, IX, and XII. Most of the compounds showed high topological polar surface area (TPSA) values and excellent enzyme inhibitory activity. The impacts of some compounds on the viability of HT-29, MDA-MB-231, and MG-63 human cancer cell lines were examined under both normoxic and hypoxic conditions, and they showed certain inhibitory effects on cell viability. Moreover, it was found that the series of compounds had the ability to raise the pH of the tumor cell microenvironment. All the results proved that saccharide-modified thiadiazole sulfonamides have important research prospects for the development of CA IX inhibitors.


2021 ◽  
Author(s):  
Syarifah Ramadhani Lubis ◽  
Subandi Subandi ◽  
Muntholib Muntholib ◽  
Jamilah Abbas ◽  
Tjandrawati Mozef

2019 ◽  
Vol 14 (12) ◽  
pp. 1934578X1988789
Author(s):  
Takahiro Deguchi ◽  
Yusuke Hata ◽  
Atsushi Tamai ◽  
Moe Yamamoto ◽  
Takanori Fujita ◽  
...  

The heartwood of Pterocarpus marsupium is called as “Asana” in Ayurveda. Its aquatic infusion was used for treating “prameha,” which indicates a polyuria disease in modern medicine. In our research program to investigate a novel agent to improve hyperuricemia, we focused on the extract of Asana as a xanthine oxidase (XOD) inhibitor. Asana extract (50% ethanolic extract, PM-ext) showed 11%, 35%, and 38% inhibition at 50, 200, and 500 µg/mL, respectively. Subsequently, PM-ext was partitioned with ethyl acetate (AcOEt), butanol, and water. Among them, AcOEt-soluble fraction indicated the most potent XOD inhibitory activity and was consecutively fractionated using various liquid chromatography to obtain liquiritigenin (1), isoliquiritigenin (2), and marsupsin (3) as active principles. Compound 1 showed 16% inhibition at 200 µM while 2 showed 20%, 32%, and 46% inhibition at 50, 100, and 200 µM, respectively. Compound 3 showed 15% inhibition at 500 µM. This is the first report on the XOD inhibitory activity of 3. From these results, PM-ext is a promising candidate material for improvement of hyperuricemia. Here, Asana was recognized as an effective material against noncommunicable disease and is expected to be developed as a functional ingredient.


Molecules ◽  
2018 ◽  
Vol 23 (5) ◽  
pp. 1107 ◽  
Author(s):  
Chi-Ya Huang ◽  
Ting-Feng Yeh ◽  
Fu-Lan Hsu ◽  
Chun-Ya Lin ◽  
Shang-Tzen Chang ◽  
...  

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