Enhancement in the Catalytic Activity of Human Salivary Aldehyde Dehydrogenase by Alliin from Garlic: Implications in Aldehyde Toxicity and Oral Health

2019 ◽  
Vol 20 (6) ◽  
pp. 506-516 ◽  
Author(s):  
Amaj A. Laskar ◽  
Danishuddin ◽  
Shaheer H. Khan ◽  
Naidu Subbarao ◽  
Hina Younus
Keyword(s):  
Catalytic Activity ◽  
Aldehyde Dehydrogenase ◽  
Active Site ◽  
Bioactive Compound ◽  
Docking Study ◽  
Initial Reaction ◽  
Active Site Residues ◽  
Binding Region ◽  
Binding Studies ◽  
Molecular Docking Study

Background: Lower human salivary aldehyde dehydrogenase (hsALDH) activity increases the risk of aldehyde mediated pathogenesis including oral cancer. Alliin, the bioactive compound of garlic, exhibits many beneficial health effects. Objective: To study the effect of alliin on hsALDH activity. Method: Enzyme kinetics was performed to study the effect of alliin on the activity of hsALDH. Different biophysical techniques were employed for structural and binding studies. Docking analysis was done to predict the binding region and the type of binding forces. Results: Alliin enhanced the dehydrogenase activity of the enzyme. It slightly reduced the Km and significantly enhanced the Vmax value. At 1 µM alliin concentration, the initial reaction rate increased by about two times. Further, it enhanced the hsALDH esterase activity. Biophysical studies indicated a strong complex formation between the enzyme and alliin (binding constant, Kb: 2.35 ± 0.14 x 103 M-1). It changes the secondary structure of hsALDH. Molecular docking study indicated that alliin interacts to the enzyme near the substrate binding region involving some active site residues that are evolutionary conserved. There was a slight increase in the nucleophilicity of active site cysteine in the presence of alliin. Ligand efficiency metrics values indicate that alliin is an efficient ligand for the enzyme. Conclusion: Alliin activates the catalytic activity of the enzyme. Hence, consumption of alliincontaining garlic preparations or alliin supplements and use of alliin in pure form may lower aldehyde related pathogenesis including oral carcinogenesis.

Development of Xanthine Based Inhibitors Targeting Phosphodiesterase 9A

2017 ◽  
Vol 14 (10) ◽  
pp. 1122-1137 ◽  
Author(s):  
Nivedita Singh ◽  
Parameswaran Saravanan ◽  
M.S. Thakur ◽  
Sanjukta Patra
Keyword(s):  
Free Energy ◽  
Active Site ◽  
Signal Transduction Pathway ◽  
Docking Study ◽  
Primary Objective ◽  
Cgmp Level ◽  
Active Site Residues ◽  
Aromatic Fragment ◽  
Docking Approach ◽  
Free Energy Of Binding

Background: Phosphodiesterases 9A (PDE9A) is one of the prominent regulating enzymes of the signal transduction pathway having highest catalytic affinity for second messenger, cGMP. When the cGMP level is lowered, an uncontrolled expression of PDE9A may lead to various neurodegenerative diseases. To regulate the catalytic activity of PDE9A, potent inhibitors are needed. Objective: The primary objective of the present study was to develop new xanthine based inhibitors targeting PDE9A. This study was an attempt to bring structural diversification in PDE9A inhibitor development because most of the existing inhibitors are constructed over pyrazolopyrimidinone scaffold. Methods: Manual designing and parallel molecular docking approach were used for the development of xanthine derivatives. In this study, N1, N3, N9 and C8 positions of xanthine scaffold were selected as substitution sites to design 200 new compounds. Reverse docking and pharmaceutical analyses were used for final validation of most promising compounds. Results: By keeping free energy of binding cut-off of -6.0 kcal/mol, 52 compounds were screened. The compounds with substitution at N1, N3 and C8 positions of xanthine showed good occupancy in PDE9A active site pocket with a significant interaction pattern. This was further validated by screening different factors such as free energy of binding, inhibition constant and interacting active site residues in the 5Å region. Substitution at C8 position with phenyl substituent determined the inhibition affinity of compounds towards PDE9A by establishing a strong hydrophobic - hydrophobic interaction. The alkyl chain at N1 position generated selectivity of compounds towards PDE9A. The aromatic fragment at N3 position increased the binding affinity of compounds. Thus, by comparative docking study, it was found that compound 39-42 formed selective interaction towards PDE9A over other members of the PDE superfamily. Conclusion: From the present study, N1, N3 and C8 positions of xanthine were concluded as the best sites for substitution for the generation of potent PDE9A inhibitors.

Structure-Based Design, Synthesis, Biological Evaluation and Molecular Docking Study of 4-Hydroxy-N'-methylenebenzohydrazide Derivatives Acting as Tyrosinase Inhibitors with Potentiate Anti-Melanogenesis Activities

2020 ◽  
Vol 16 (7) ◽  
pp. 892-902 ◽  
Author(s):  
Aida Iraji ◽  
Mahsima Khoshneviszadeh ◽  
Pegah Bakhshizadeh ◽  
Najmeh Edraki ◽  
Mehdi Khoshneviszadeh
Keyword(s):  
Molecular Docking ◽  
Active Site ◽  
Competitive Inhibition ◽  
Docking Study ◽  
Biological Evaluation ◽  
Primary Response ◽  
Ratio Method ◽  
Molecular Docking Study ◽  
Metal Chelating

Background: Melanogenesis is a process of melanin synthesis, which is a primary response for the pigmentation of human skin. Tyrosinase is a key enzyme, which catalyzes a ratelimiting step of the melanin formation. Natural products have shown potent inhibitors, but some of these possess toxicity. Numerous synthetic inhibitors have been developed in recent years may lead to the potent anti– tyrosinase agents. Objective: A number of 4-hydroxy-N'-methylenebenzohydrazide analogues with related structure to chalcone and tyrosine were constructed with various substituents at the benzyl ring of the molecule and evaluate as a tyrosinase inhibitor. In addition, computational analysis and metal chelating potential have been evaluated. Methods: Design and synthesized compounds were evaluated for activity against mushroom tyrosinase. The metal chelating capacity of the potent compound was examined using the mole ratio method. Molecular docking of the synthesized compounds was carried out into the tyrosine active site. Results: Novel 4-hydroxy-N'-methylenebenzohydrazide derivatives were synthesized. The two compounds 4c and 4g showed an IC50 near the positive control, led to a drastic inhibition of tyrosinase. Confirming in vitro results were performed via the molecular docking analysis demonstrating hydrogen bound interactions of potent compounds with histatidine-Cu+2 residues with in the active site. Kinetic study of compound 4g showed competitive inhibition towards tyrosinase. Metal chelating assay indicates the mole fraction of 1:2 stoichiometry of the 4g-Cu2+ complex. Conclusion: The findings in the present study demonstrate that 4-Hydroxy-N'- methylenebenzohydrazide scaffold could be regarded as a bioactive core inhibitor of tyrosinase and can be used as an inspiration for further studies in this area.

Novel coumarin containing dithiocarbamate derivatives as potent α-glucosidase inhibitors for management of type 2 diabetes

2020 ◽  
Vol 16 ◽  
Author(s):  
Marjan Mollazadeh ◽  
Maryam Mohammadi-Khanaposhtani ◽  
Yousef Valizadeh ◽  
Afsaneh Zonouzi ◽  
Mohammad Ali Faramarzi ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Kinetic Study ◽  
Active Site ◽  
Docking Study ◽  
Secondary Amines ◽  
Molecular Docking Study ◽  
Glucosidase Inhibitors ◽  
Dithiocarbamate Derivatives

Background: α-Glucosidase is a hydrolyze enzyme that plays a crucial role in degradation of carbohydrates and starch to glucose. Hence, α-glucosidase is an important target in the carbohydrate mediated diseases such as diabetes mellitus. Objective: In this study, novel coumarin containing dithiocarbamate derivatives 4a-n were synthesized and evaluated against α-glucosidase in vitro and in silico. Methods: These compounds were obtained of reaction between 4-(bromomethyl)-7-methoxy-2H-chromen-2-one 1, carbon disulfide 2, and primary or secondary amines 3a-n in the presence potassium hydroxide and ethanol at room temperature. In vitro α-glucosidase inhibition and kinetic study of these compounds were performed. Furthermore, docking study of the most potent compounds was also performed by Auto Dock Tools (version 1.5.6). Results: Obtained results showed that all the synthesized compounds exhibited prominent inhibitory activities (IC50 = 85.0 ± 4.0-566.6 ± 8.6 μM) in comparison to acarbose as standard inhibitor (IC50 = 750.0 ± 9.0 µM). Among them, secondary amine derivative 4d with pendant indole group was the most potent inhibitor. Enzyme kinetic study of the compound 4d revealed that this compound compete with substrate to connect to the active site of α-glucosidase and therefore is a competitive inhibitor. Also, molecular docking study predicted that this compound as well interacted with α-glucosidase active site pocket. Conclusion: Our results suggest that the coumarin-dithiocarbamate scaffold can be a promising lead structure for design potent α-glucosidase inhibitors for treatment of type 2 diabetes.

scholarly journals Azadirachtin-A a bioactive compound from Azadiracta indica is a potential inhibitor of SARS-CoV-2 main protease

2021 ◽  
Vol 01 (01) ◽  
pp. 01-08
Author(s):  
Eustace Berinyuy ◽  
◽  
Jonathan Ibrahim ◽  
Blessing Alozieuwa
Keyword(s):  
Bioactive Compound ◽  
Docking Study ◽  
Preclinical Study ◽  
Binding Modes ◽  
Molecular Docking Study ◽  
Potential Inhibitor ◽  
Main Protease ◽  
Binding Cavity ◽  
Approved Drugs ◽  
Azadirachtin A

Despite the growing scientific interest in finding effective treatment, SARS-CoV-2 virus remains a global major health burden and public health emergency. SARS-CoV main protease (Mpro) also known as chymotrypsin-like protease (3CLpro) is an important protein identified to be vital for SARS-CoV-2 survival. However, to date, there are no clinically approved drugs or antibodies specific for SARS-CoV-2. In the present study, we evaluated the interaction of 3CLpro with azadirachtin-A a bioactive compound from Azadiracta indica using in silico molecular docking study. Our results revealed that Azadiractin A docked well into the binding cavity of 3CLproSARS-CoV-2 with binding affinities ranges between -6.3 and -5.20 kcal/mol, and Pkd of 5.82~6.10 for the ten best binding modes. Azadiractin interacted with the active site of 3CLpro-SARS-CoV-2 by 2 conventional hydrogen bonding to HIS163 and GLU166, C-H interactions with HIS127, and alkyl interaction with PRO168 of the 3CLpro-SARS-CoV-2. We also found that the Azadiractin-A_3CLpro-SARS-CoV-2 complex is stabilized by various Vander wall forces with ASN142, LEU141, PHE140, MET165, GLN189, LEU167, THR190, and ALA191. In conclusion, our results suggested that Azadirachtin-A could be a potential inhibitor of SARS-CoV-2 main protease, thus worthy of further preclinical study.

Ex vivo binding studies of the anti-cancer drug noscapine with human hemoglobin: a spectroscopic and molecular docking study

2021 ◽  
Author(s):  
Heerak Chugh ◽  
Pramod Kumar ◽  
Neeraj Kumar ◽  
Rajesh K. Gaur ◽  
Gagan Dhawan ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Ex Vivo ◽  
Docking Study ◽  
Cancer Drug ◽  
Stable Complex ◽  
Human Hemoglobin ◽  
Binding Studies ◽  
Molecular Docking Study ◽  
Hemoglobin A ◽  
Anti Cancer

Noscapine binds human hemoglobin spontaneously forming a stable complex that affects noscapine's ADMET profile, bioavailability and toxicity.

scholarly journals Novel Group of AChE Reactivators—Synthesis, In Vitro Reactivation and Molecular Docking Study

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2291 ◽  
Author(s):  
David Malinak ◽  
Eugenie Nepovimova ◽  
Daniel Jun ◽  
Kamil Musilek ◽  
Kamil Kuca
Keyword(s):  
Molecular Docking ◽  
Molecular Modelling ◽  
Active Site ◽  
Molecular Design ◽  
Docking Study ◽  
The Novel ◽  
Molecular Docking Study ◽  
Causal Treatment ◽  
Modelling Study

The acetylcholinesterase (AChE) reactivators (e.g., obidoxime, asoxime) became an essential part of organophosphorus (OP) poisoning treatment, together with atropine and diazepam. They are referred to as a causal treatment of OP poisoning, because they are able to split the OP moiety from AChE active site and thus renew its function. In this approach, fifteen novel AChE reactivators were determined. Their molecular design originated from former K-oxime compounds K048 and K074 with remaining oxime part of the molecule and modified part with heteroarenium moiety. The novel compounds were prepared, evaluated in vitro on human AChE (HssAChE) inhibited by tabun, paraoxon, methylparaoxon or DFP and compared to commercial HssAChE reactivators (pralidoxime, methoxime, trimedoxime, obidoxime, asoxime) or previously prepared compounds (K048, K074, K075, K203). Some of presented oxime reactivators showed promising ability to reactivate HssAChE comparable or higher than the used standards. The molecular modelling study was performed with one compound that presented the ability to reactivate GA-inhibited HssAChE. The SAR features concerning the heteroarenium part of the reactivator’s molecule are described.

scholarly journals Identification of Compounds from Nigella Sativa as New Potential Inhibitors of 2019 Novel Coronasvirus (Covid-19): Molecular Docking Study.

2020 ◽  
Author(s):  
Salim Bouchentouf ◽  
Noureddine Missoum
Keyword(s):  
Molecular Docking ◽  
Active Site ◽  
Nigella Sativa ◽  
Specific Treatment ◽  
Docking Study ◽  
Clinical Test ◽  
Molecular Docking Study ◽  
Great Opportunity ◽  
Drug Candidates ◽  
Energy Score

<p>The spread of the global COVID-19 pandemic, the lack of specific treatment and the urgent situation requires use of all resources to remedy this scourge. In the present study, using molecular docking, we identify new probable inhibitors of COVID-19 by molecules from <i>Nigella sativa L</i>, which is highly reputed healing herb in North African societies and both Islamic and Christian traditions. The discovery of the M<sup>pro</sup> protease structure in COVID-19 provides a great opportunity to identify potential drug candidates for treatment. Focusing on the main proteases in CoVs (3CL<sup>pro</sup>/M<sup>pro</sup>) (PDB ID 6LU7 and 2GTB); docking of compounds from <i>Nigella Sativa</i> and drugs under clinical test was performed using Molecular Operating Environment software (MOE). Nigelledine docked into 6LU7 active site gives energy complex about -6.29734373 Kcal/mol which is close to the energy score given by chloroquine (-6.2930522 Kcal/mol) and better than energy score given by hydroxychloroquine (-5.57386112 Kcal/mol) and favipiravir (-4.23310471 kcal/mol). Docking into 2GTB active site showed that α- Hederin gives energy score about-6.50204802 kcal/mol whcih is better energy score given by chloroquine (-6.20844936 kcal/mol), hydroxychloroquine (-5.51465893 kcal/mol)) and favipiravir (-4.12183571kcal/mol). Nigellidine and α- Hederin appeared to have the best potential to act as COVID-19 treatment. Further, researches are necessary to testify medicinal use of identified and to encourage preventive use of <i>Nigella Sativa </i>against coronavirus infection.</p>

scholarly journals The Structural Basis for Calcium Inhibition of Lipid Kinase PI4K IIα and Comparison With the Apo State

2016 ◽  
pp. 987-993
Author(s):  
A. BAUMLOVA ◽  
J. GREGOR ◽  
E. BOURA
Keyword(s):  
Catalytic Activity ◽  
Active Site ◽  
Synaptic Vesicles ◽  
Structural Basis ◽  
Active Site Residues ◽  
Precursor Molecule ◽  
Lipid Kinase ◽  
Lipid Molecule ◽  
Phosphatidylinositol 4 ◽  
Apo State

PI4K IIα is a critical enzyme for the maintenance of Golgi and is also known to function in the synaptic vesicles. The product of its catalytical function, phosphatidylinositol 4-phosphate (PI4P), is an important lipid molecule because it is a hallmark of the Golgi and TGN, is directly recognized by many proteins and also serves as a precursor molecule for synthesis of higher phosphoinositides. Here, we report crystal structures of PI4K IIα enzyme in the apo-state and inhibited by calcium. The apo-structure reveals a surprising rigidity of the active site residues important for catalytic activity. The structure of calcium inhibited kinase reveals how calcium locks ATP in the active site.

scholarly journals MOLECULAR DOCKING STUDY TO IDENTIFY POTENTIAL INHIBITOR OF COVID-19 MAIN PROTEASE ENZYME: AN IN-SILICO APPROACH

2020 ◽  
Author(s):  
Anurag Agrawal ◽  
Nem Kumar Jain ◽  
Neeraj Kumar ◽  
Giriraj T Kulkarni
Keyword(s):  
Molecular Docking ◽  
Active Site ◽  
Docking Study ◽  
Molecular Docking Study ◽  
Potential Threat ◽  
Discovery Studio ◽  
Chemical Structures ◽  
Potential Inhibitor ◽  
Protease Enzyme ◽  
Main Protease

This study belongs to identification of suitable COVID-19 inhibitors<br><div><br></div><div>Coronavirus became pandemic very soon and is a potential threat to human lives across the globe. No approved drug is currently available therefore an urgent need has been developed for any antiviral therapy for COVID-19. For the molecular docking study, ten herbal molecules have been included in the current study. The three-dimensional chemical structures of molecules were prepared through ChemSketch 2015 freeware. Molecular docking study was performed using AutoDock 4.2 simulator and Discovery studio 4.5 was employed to predict the active site of target enzyme. Result indicated that all-natural molecules found in the active site of enzyme after molecular docking. Oxyacanthine and Hypericin (-10.990 and -9.05 and kcal/mol respectively) have shown good binding efficacy among others but Oxyacanthine was the only natural product which made some of necessary interactions with residues in the enzyme require for target inhibition. Therefore Oxyacanthine may be considered to be potential inhibitor of main protease enzyme of virus but need to be explored for further drug development process. <br></div>

scholarly journals Isoniazid-Isatin Hydrazone Derivatives: Synthesis, Antitubercular Activity and Molecular Docking Studies

2021 ◽  
Vol 18 (21) ◽  
pp. 39
Author(s):  
Mardi Santoso ◽  
Muhammad Riza Ghulam Fahmi ◽  
Yehezkiel Steven Kurniawan ◽  
Taslim Ersam ◽  
Sri Fatmawati ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Mycobacterium Tuberculosis ◽  
Molecular Docking ◽  
Active Site ◽  
Antitubercular Activity ◽  
Docking Study ◽  
Positive Control ◽  
Tuberculosis H37rv ◽  
Molecular Docking Study

This study examined the synthesis of isoniazid-isatin hydrazone derivatives 5-7, followed by an investigation on the in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv, and molecular docking. A yield of 81 - 92 % of these compounds was achieved, with structural characterization by spectroscopic methods (FTIR, NMR, HRMS). The in vitro antitubercular activity was evaluated against M. tuberculosis H37Rv, and the highest effect was observed in compound 7, with a minimum inhibitory concentration (MIC) of 0.017 mM, lower than rifampicin (MIC 0.048 mM), which served as the positive control. In addition, the molecular docking of 5-7 was performed to visualize the interaction of isoniazid-isatin hydrazone derivatives with the active site of InhA receptor, which was in agreement with the experimental data. The hydrogen bonding with Ser94 and pi-pi interaction with Phe41 and/or Phe97 on the InhA active site was pivotal for the antitubercular activity. HIGHLIGHTS Tuberculosis caused by Mycobacterium tuberculosis is one of the top ten leading causes of death globally The first and second lines of antituberculosis drugs are the prevalent treatment for this disease, but they show several drawbacks and are exacerbated by the occurrence of drug resistance The isoniazid-isatin hydrazone derivatives were designed through molecular hybridization and synthesized effectively and exhibited moderate to high activity against tuberculosis H37Rv Molecular docking study demonstrated that the hydrogen bonding with Ser94 and the pi-pi interaction with Phe41 and/or Phe97 are important for antitubercular activity GRAPHICAL ABSTRACT

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