scholarly journals The Physical Adsorption of Gelatinized Starch With Tannic Acid Decreases the Inhibitory Activity of the Polyphenol Against α-Amylase

Author(s):  
Yueyi Wang ◽  
Fangting Bai ◽  
Junwei Cao ◽  
Lijun Sun

The effects of mixing orders of tannic acid (TA), starch and α-amylase on the enzyme inhibition of TA were studied, including mixing TA with α-amylase before starch addition (order 1), mixing TA with pre-gelatinized starch before α-amylase addition (order 2) and co-gelatinizing TA with starch before α-amylase addition (order 3). It was found that the enzyme inhibition was always highest for order 1 because TA could bind with the enzyme active site thoroughly before digestion occurred. Both order 2 and 3 reduced α-amylase inhibition through decreasing binding of TA with the enzyme, which resulted from the non-covalent physical adsorption of TA with gelatinized starch. Interestingly, at low TA concentration, α-amylase inhibition for order 2 was higher than order 3, while at high TA concentration, the inhibition was shown with opposite trend, which arose from the difference in the adsorption property between the pre-gelatinized and co-gelatinized starch at the corresponding TA concentrations. Besides, both the crystalline structures and apparent morphology of starch were not significantly altered by TA addition for order 2 and 3. Conclusively, although a polyphenol may have an acceptable inhibitory activity in vitro, the actual effect may not reach the expected one when taking processing procedures into account.

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1233
Author(s):  
Yueyi Wang ◽  
Shuangshuang Li ◽  
Fangting Bai ◽  
Junwei Cao ◽  
Lijun Sun

The effects of mixing orders of tannic acid (TA), starch, and α-amylase on the enzyme inhibition of TA were studied, including mixing TA with α-amylase before starch addition (order 1), mixing TA with pre-gelatinized starch before α-amylase addition (order 2) and co-gelatinizing TA with starch before α-amylase addition (order 3). It was found that the enzyme inhibition was always highest for order 1 because TA could bind with the enzyme active site thoroughly before digestion occurred. Both order 2 and 3 reduced α-amylase inhibition through decreasing binding of TA with the enzyme, which resulted from the non-covalent physical adsorption of TA with gelatinized starch. Interestingly, at low TA concentration, α-amylase inhibition for order 2 was higher than order 3, while at high TA concentration, the inhibition was shown with the opposite trend, which arose from the difference in the adsorption property between the pre-gelatinized and co-gelatinized starch at the corresponding TA concentrations. Moreover, both the crystalline structures and apparent morphology of starch were not significantly altered by TA addition for order 2 and 3. Conclusively, although a polyphenol has an acceptable inhibitory activity in vitro, the actual effect may not reach the expected one when taking processing procedures into account.


2015 ◽  
Vol 54 (28) ◽  
pp. 8217-8221 ◽  
Author(s):  
Tahiri Sylla ◽  
Laurent Pouységu ◽  
Grégory Da Costa ◽  
Denis Deffieux ◽  
Jean-Pierre Monti ◽  
...  

2021 ◽  
Vol 11 (5) ◽  
pp. 13347-13358

Identification of potential phytocompound from Phoenix sylvestris RoxB. For anti-diabetic potential and its validation through computational methods. Partially purified fraction evaluated for Alpha-amylase enzyme inhibition and GC-MS identified fraction validated compounds for potential anti-diabetic activity by Auto docking method. The phytocompounds investigation revealed maximum abundance of total phenol (31.55±0.55 μg/mg equivalent to Gallic acid) and flavonoid (52.90±0.08 μg/mg equivalent to quercetin) content in ethyl acetate extract. Ethyl acetate extract interestingly showed maximum alpha-amylase inhibition (71.15 %, IC50- 98.50±0.10 μg/ml), which was a mixed type of inhibition as compared to acarbose (78.64%, IC50- 88.61±0.50 μg/ml), which showed a competitive type of inhibition analyzed by Line weaver-Burk double reciprocal plot versus 1/v and 1/s. The docking study illustrated that Lupenyl acetate compound was the most active compound that showed maximum binding free energy (-7.16 Kcal/mol) and interacted with the Val64, Asn88, Gly90, Asn87, Arg87, Arg10, Gly9, Gln7, Gln5, Thr5, Trp221, Phe222, Asn5, Pro223, Ser3, Ser226, Lys227 and Gly225 amino acid residues which inhibited the alpha-amylase more efficiently than acarbose (binding energy -4.71 Kcal/mol). The present study concluded that the components of ethyl acetate extract had Alpha enzyme inhibition with reducing potential, and it may be due to the synergistic effect. The study suggested ethyl acetate extract as a natural promising therapeutic compound for the treatment of diabetes.


Author(s):  
Sushant A Shengule ◽  
Sanjay Mishra ◽  
Shweta Bodhale

 Objective: The present study was initiated to screen the hydroethanolic bark extract for α-amylase inhibitory activity and standardization of the Terminalia arjuna for polyphenolic phytochemicals using high-performance liquid chromatography-photo diode array (HPLC-PDA) method.Methods: The T. arjuna bark sample was extracted with ethanol: water (70:30 v/v) using Soxhlet extraction. A Dionex P680 HPLC system was used to acquire chromatograms. The screening of extract of T. arjuna bark has performed for in vitro α-amylase inhibitory assay. Each experiment was repeated 3 times. All values were expressed mean ± standard deviation.Results: The content of arjunetin, arjungenin, gallic acid, ellagic acid, and quercetin was 0.47, 8.22, 2.443, 7.901, and 3.20 mg/g, respectively, in a hydroethanolic extract of T. arjuna. The hydroethanolic extract of T. arjuna bark and acarbose has shown an inhibitory activity with an IC50 value 145.90 and 62.35 μg/mL, respectively.Conclusion: The hydroethanolic extract T. arjuna bark demonstrates α-amylase inhibitory activity due to a synergistic effect of the phytochemical constituents present in it. This study suggests that one of the mechanisms of this plant for antidiabetic activity is through the inhibition of α-amylase enzyme.


2020 ◽  
Vol 17 (10) ◽  
pp. 1216-1226
Author(s):  
Mohammed Hussen Bule ◽  
Roghaieh Esfandyari ◽  
Tadesse Bekele Tafesse ◽  
Mohsen Amini ◽  
Mohammad Ali Faramarzi ◽  
...  

Background: α-Glucosidase inhibitors hinder the carbohydrate digestion and play an important role in the treatment of diabetes mellitus. α-glucosidase inhibitors available on the market are acarbose, miglitol, and voglibose. However, the use of acarbose is diminishing due to related side effects like diarrhea, bloating and abdominal distension. Objectives: This study aimed to synthesize 2,4,6-triaryl pyrimidines derivatives, screen their α- glucosidase inhibitory activity, perform kinetic and molecular docking studies. Methods: A series of 2,4,6-triaryl pyrimidine derivatives were synthesized and their α-glucosidase inhibitory activity was screened in vitro. Pyrimidine derivatives 4a-m were synthesized via a twostep reaction with a yield between 49 and 93%. The structure of the synthesized compounds was confirmed by different spectroscopic techniques (IR, NMR and MS). The in vitro α-glucosidase inhibition activities of the synthesized compounds 4a-m was also evaluated against Saccharomyces cerevisiae α-glucosidase. Results and Discussion: The majority of synthesized compounds had α-glucosidase inhibitory activity. Particularly compounds 4b and 4g were the most active compounds with an IC50 value of 125.2± 7.2 and 139.8 ± 8.1 μM respectively. The kinetic study performed for the most active compound 4b revealed that the compound was a competitive inhibitor of Saccharomyces cerevisiae α-glucosidase with Ki of 122 μM. The molecular docking study also revealed that the two compounds have important binding interactions with the enzyme active site. Conclusion: 2,4,6-triarylpyrimidine derivative 4a-m were synthesized and screened for α- glucosidase inhibitory activity. Most of the synthesized compounds possess α-glucosidase inhibitory activity, and compound 4b demonstrated the most significant inhibitory action as compared to acarbose.


Author(s):  
Kushagra Dubey ◽  
Raghvendra Dubey ◽  
Revathi Gupta ◽  
Arun Gupta

Background: Diosmin is a flavonoid obtained from the citrus fruits of the plants. Diosmin has blood lipid lowering activities, antioxidant activity, enhances venous tone and microcirculation, protects capillaries, mainly by reducing systemic oxidative stress. Objective: The present study demonstrates the potential of Diosmin against the enzymes aldose reductase, α-glucosidase, and α-amylase involved in diabetes and its complications by in vitro evaluation and reverse molecular docking studies. Method: The assay of aldose reductase was performed by using NADPH as starting material and DL-Glyceraldehyde as a substrate. DNS method was used for alpha amylase inhibition and in alpha glucosidase inhibitory activity p-nitrophenyl glucopyranoside (pNPG) was used as substrate. The reverse molecular docking studies was performed by using Molegro software (MVD) with grid resolution of 30 Å. Result: Diosmin shows potent inhibitory effect against aldose reductase (IC50:333.88±0.04 µg/mL), α-glucosidase (IC50:410.3±0.01 µg/mL) and α-amylase (IC50: 404.22±0.02 µg/mL) respectively. The standard drugs shows moderate inhibitory activity for enzymes. The MolDock Score of Diosmin was -224.127 against aldose reductase, -168.17 against α-glucosidase and -176.013 against α-amylase respectively, which was much higher than standard drugs. Conclusion: From the result it was concluded that diosmin was a potentially inhibitor of aldose reductase, alpha amylase and alpha glucosidase enzymes then the standard drugs and it will be helpful in the management of diabetes and its complications. This will also be benevolent to decrease the socio economical burden on the middle class family of the society.


1940 ◽  
Vol 18b (11) ◽  
pp. 345-350 ◽  
Author(s):  
H. B. Collier

Mammalian catalase and cytochrome oxidase are strongly inhibited by the hydroxy derivatives of phenothiazine and by p-hydroxylaminobenzenesulphonamide. Phenothiazine, sulphanilamide, and sulphapyridine have little or no effect. Cytochrome-c is irreversibly reduced by the hydroxy-sulphanilamide, as indicated by spectroscopic observation. The inhibitory activity apparently depends on the presence of the hydroxyl group. The relation of these findings to the vermicidal and bactericidal action of the compounds is discussed.Phenothiazine and thionol have no effect on Ascaris lumbricoides in vitro.


2015 ◽  
Vol 127 (28) ◽  
pp. 8335-8339 ◽  
Author(s):  
Tahiri Sylla ◽  
Laurent Pouységu ◽  
Grégory Da Costa ◽  
Denis Deffieux ◽  
Jean-Pierre Monti ◽  
...  

1985 ◽  
Vol 226 (2) ◽  
pp. 537-544 ◽  
Author(s):  
F De Matteis ◽  
A H Gibbs ◽  
C Harvey

The structural requirements for the inhibition of ferrochelatase by N-alkylated porphyrins were investigated and experiments carried out to explore the mechanism of enzyme inhibition. Three dicarboxylic porphyrins, all substrates of the enzyme, are strongly inhibitory when N-alkylated; in contrast, uroporphyrin and coproporphyrin (which are not substrates) do not inhibit after N-alkylation. Free carboxylic acid functions are required for inhibition, as the methyl ester derivatives are not themselves inhibitory. Porphyrins bearing the alkyl group on the pyrrole nitrogen of rings C and D are less effective inhibitors, particularly when zinc is chelated in the centre of the tetrapyrrole or the N-alkyl group is relatively large in size. The substituents at the 2- and 4-positions of the porphyrin system may also affect the inhibitory activity, particularly for the isomers with ring C and D alkylated. The zinc chelates of several N-alkylprotoporphyrins are inhibitory towards haem oxygenase, another haem-binding enzyme, and also in this case increasing the size of the alkyl group decreased the inhibitory activity, particularly for isomers with ring C or D alkylated. The inhibition could be reversed by prolonged incubation with excess porphyrin substrate, but dealkylation of the N-alkylporphyrin during enzyme inhibition could not be demonstrated. It is concluded (a) that N-alkylated dicarboxylic porphyrins compete reversibly with the porphyrin substrate for the enzyme active site and (b) that the structural and steric factors discussed above affect the inhibitory activity by modifying the affinity of the N-alkylporphyrin inhibitor for the enzyme.


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