scholarly journals Screening and Characterizing Tyrosinase Inhibitors from Salvia miltiorrhiza and Carthamus tinctorius by Spectrum-Effect Relationship Analysis and Molecular Docking

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ya-Li Wang ◽  
Guang Hu ◽  
Qian Zhang ◽  
Yu-Xiu Yang ◽  
Qiao-Qiao Li ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Amino Acid ◽  
Salvia Miltiorrhiza ◽  
Carthamus Tinctorius ◽  
Amino Acid Residues ◽  
Analysis Method ◽  
Effect Relationship ◽  
Relationship Analysis ◽  
Ms Analysis ◽  
Spectrum Effect

Tyrosinase (TYR) is a rate-limiting enzyme in the synthesis of melanin, while direct TYR inhibitors are a class of important clinical antimelanoma drugs. This study established a spectrum-effect relationship analysis method and high-performance liquid chromatography-mass spectrometry (LC-MS) analysis method to screen and identify the active ingredients that inhibited TYR in Salvia miltiorrhiza–Carthamus tinctorius (Danshen–Honghua, DH) herbal pair. Seventeen potential active compounds (peaks) in the extract of DH herbal pair were predicted, and thirteen of them were tentatively identified by LC-MS analysis. Furthermore, TYR inhibitory activities of five pure compounds obtained from the DH herbal pair were validated in the test in which kojic acid served as a positive control drug. Among them, three compounds including protocatechuic aldehyde, hydroxysafflor yellow A, and tanshinone IIA were verified to have high TYR inhibitory activity (IC50 value of 455, 498, and 1214 μM, resp.) and bind to the same amino acid residues in TYR catalytic pocket according to the results of the molecular docking test. However, the other two compounds lithospermic acid and salvianolic acid A had a weak effect on TYR, as they do not combine with the active amino acid residues or act on the active center of TYR. Therefore, the developed methods (spectrum-effect relationship analysis and molecular docking) could be used to effectively screen TYR inhibitors in complex mixtures such as natural products.

scholarly journals Screening of Potential Thrombin and Factor Xa Inhibitors from the Danshen–Chuanxiong Herbal Pair through a Spectrum–Effect Relationship Analysis

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7293
Author(s):  
Xu Wang ◽  
Dai-Yan Zhang ◽  
Shi-Jun Yin ◽  
Hui Jiang ◽  
Min Lu ◽  
...  
Keyword(s):  
Chlorogenic Acid ◽  
Inhibitory Activity ◽  
Factor Xa ◽  
Binding Energies ◽  
Tanshinone Iia ◽  
Effect Relationship ◽  
Tanshinone I ◽  
Relationship Analysis ◽  
Ms Analysis ◽  
Spectrum Effect

In this study; a spectrum–effect relationship analysis combined with a high-performance liquid chromatography–mass spectrometry (LC–MS) analysis was established to screen and identify active components that can inhibit thrombin and factor Xa (THR and FXa) in Salviae Miltiorrhizae Radix et Rhizoma–Chuanxiong Rhizoma (Danshen–Chuanxiong) herbal pair. Ten potential active compounds were predicted through a canonical correlation analysis (CCA), and eight of them were tentatively identified through an LC–MS analysis. Furthermore; the enzyme inhibitory activity of six available compounds; chlorogenic acid; Z-ligustilide; caffeic acid; ferulic acid; tanshinone I and tanshinone IIA; were tested to verify the feasibility of the method. Among them; chlorogenic acid was validated to possess a good THR inhibitory activity with IC50 of 185.08 µM. Tanshinone I and tanshinone IIA are potential FXa inhibitors with IC50 of 112.59 µM and 138.19 µM; respectively. Meanwhile; molecular docking results show that tanshinone I and tanshinone IIA; which both have binding energies of less than −7.0 kcal·mol−1; can interact with FXa by forming H-bonds with residues of SER214; GLY219 and GLN192. In short; the THR and FXa inhibitors in the Danshen–Chuanxiong herbal pair have been successfully characterized through a spectrum–effect relationship analysis and an LC–MS analysis.

scholarly journals In Silico Prediction, Molecular Docking and Dynamics Studies of Steroidal Alkaloids of Holarrhena pubescens Wall. ex G. Don to Guanylyl Cyclase C: Implications in Designing of Novel Antidiarrheal Therapeutic Strategies

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4147
Author(s):  
Neha Gupta ◽  
Saurav Kumar Choudhary ◽  
Neeta Bhagat ◽  
Muthusamy Karthikeyan ◽  
Archana Chaturvedi
Keyword(s):  
Molecular Docking ◽  
Amino Acid ◽  
Guanylyl Cyclase ◽  
Extracellular Domain ◽  
Enterotoxigenic Escherichia Coli ◽  
Watery Diarrhea ◽  
Guanylyl Cyclase C ◽  
Amino Acid Residues ◽  
Lead Compounds

The binding of heat stable enterotoxin (STa) secreted by enterotoxigenic Escherichia coli (ETEC) to the extracellular domain of guanylyl cyclase c (ECDGC-C) causes activation of a signaling cascade, which ultimately results in watery diarrhea. We carried out this study with the objective of finding ligands that would interfere with the binding of STa on ECDGC-C. With this view in mind, we tested the biological activity of a alkaloid rich fraction of Holarrhena pubescens against ETEC under in vitro conditions. Since this fraction showed significant antibacterial activity against ETEC, we decided to test the screen binding affinity of nine compounds of steroidal alkaloid type from Holarrhena pubescens against extracellular domain (ECD) by molecular docking and identified three compounds with significant binding energy. Molecular dynamics simulations were performed for all the three lead compounds to establish the stability of their interaction with the target protein. Pharmacokinetics and toxicity profiling of these leads demonstrated that they possessed good drug-like properties. Furthermore, the ability of these leads to inhibit the binding of STa to ECD was evaluated. This was first done by identifying amino acid residues of ECDGC-C binding to STa by protein–protein docking. The results were matched with our molecular docking results. We report here that holadysenterine, one of the lead compounds that showed a strong affinity for the amino acid residues on ECDGC-C, also binds to STa. This suggests that holadysenterine has the potential to inhibit binding of STa on ECD and can be considered for future study, involving its validation through in vitro assays and animal model studies.

Spatial Structure of the Acth-(6-9)-PGP Molecule

2021 ◽  
Vol 43 (5) ◽  
pp. 500-500
Author(s):  
Namiq Akhmedov Namiq Akhmedov ◽  
Leyla Agayeva Leyla Agayeva ◽  
Gulnara Akverdieva Gulnara Akverdieva ◽  
Rena Abbasli and Larisa Ismailova Rena Abbasli and Larisa Ismailova
Keyword(s):  
Amino Acid ◽  
Spatial Structure ◽  
Main Chain ◽  
Low Energy ◽  
Dihedral Angles ◽  
Amino Acid Residues ◽  
Analysis Method ◽  
Theoretical Conformational Analysis ◽  
Energy Of Hydrogen Bonds ◽  
Low Energy Conformations

The spatial structure of ACTH-(6-9)-PGP molecule has been investigated using theoretical conformational analysis method. Amino acid sequence of the N-terminal pentapeptide fragment of His-Phe-Arg-Trp-Pro of this molecule conforms to the fragment 6-9 of ACTH hormone. Calculations of conformational states of this molecule are carried out regarding nonvalent, electrostatic and torsional interactions and the energy of hydrogen bonds. The spatial structure of the His-Phe-Arg-Trp-Pro-Gly-Pro molecule was estimated on the low–energy conformations of the N-terminal tetrapeptide fragment His-Phe-Arg-Trp and C-terminal tripeptide fragment Pro-Gly-Pro of this molecule. It is shown that the spatial structure of heptapeptide molecule can be presented by 11 low-energy forms of the main chain. The low–energy conformations of this molecule, the values of dihedral angles of the backbone and side chains of the amino acid residues were founded and the energies of intra- and inter-residual interactions were determined.

scholarly journals Molecular Modification of Fluoroquinolone-Biodegrading Enzymes Based on Molecular Docking and Homology Modelling

2019 ◽  
Vol 16 (18) ◽  
pp. 3407 ◽  
Author(s):  
Liu ◽  
Sun ◽  
Cui ◽  
Ding
Keyword(s):  
Molecular Docking ◽  
Amino Acid ◽  
Homology Modelling ◽  
Binding Affinities ◽  
The Novel ◽  
Amino Acid Residues ◽  
Degrading Enzyme ◽  
Degrading Enzymes ◽  
Docking Method ◽  
Degradation Effect

To improve the biodegradation efficiency of fluoroquinolone antibiotics during sewage treatment, fluoroquinolone aerobic, anaerobic and facultative degrading enzymes for fluoroquinolone degradation were modified by molecular docking and homology modelling. First, amino acid residues of the binding sites of degrading enzymes for the target fluoroquinolones ciprofloxacin (CIP), norfloxacin (NOR) and ofloxacin (OFL) were analysed by the molecular docking method. The hydrophobic amino acid residues within 5 Å of the target fluoroquinolone molecules were selected as the modification sites. The hydrophobic amino acid residues at the modified sites were replaced by the hydrophilic amino acid residues, and 150 amino acid sequence modification schemes of the degrading enzymes were designed. Subsequently, a reconstruction scheme of the degrading enzyme amino acid sequence reconstruction scheme was submitted to the SWISS-MODEL server and a selected homology modelling method was used to build a new structure of the degrading enzyme. At the same time, the binding affinities between the novel degrading enzymes and the target fluoroquinolones (represented by the docking scoring function) were evaluated by the molecular docking method. It was found that the novel enzymes can simultaneously improve the binding affinities for the three target fluoroquinolones, and the degradation ability of the six modification schemes was increased by more than 50% at the same time. Among the novel enzymes, the affinity effect of the novel anaerobic enzyme (6-1) with CIP, NOR and OFL was significantly increased, with increases of 129.24%, 165.06% and 169.59%, respectively, followed by the facultative enzyme and aerobic enzyme. In addition, the designed degrading enzymes had certain selectivity for the degradation of the target quinolone. Among the novel enzymes, the binding affinities of the novel anaerobic enzyme (6-3) and CIP, the novel aerobic enzyme (3-6) and NOR, and the novel facultative enzyme (13-6) and OFL were increased by 149.71%, 178.57% and 297.12% respectively. Calculations using the Gaussian09 software revealed that the degradation reaction barrier of the novel degrading enzyme (7-1) and CIP NOR and OFL decreased by 37.65 kcal·mol−1, 6.28 kcal·mol−1 and 6.28 kcal·mol−1, respectively, which would result in efficient degradation of the target fluoroquinolone molecules. By analysing the binding affinity of the degrading enzymes before and after the modification with methanol, it was further speculated that the degradation effect of the modified aerobic degrading enzymes on organic matter was lower than that before the modification, and the increase or decrease in the degradation effect was less than 10%. The mechanism analysis found that the interaction between the modified amino acid residues of the degrading enzymes and the fluoroquinolone molecules increased. The average distance between the amino acid residues and the fluoroquinolone molecules represented a comprehensive affinity effect, and its value was positively correlated with the degradation effect of the novel degrading enzymes.

scholarly journals Construction of immunoglobulin-binding peptides based on analysis of the protein A of Staphylococcus aureus interaction with immunoglobulins Fc fragment

2019 ◽  
Vol 55 (4) ◽  
pp. 447-454
Author(s):  
A. V. Lapko ◽  
E. S. Pustyul’ga ◽  
V. P. Golubovich
Keyword(s):  
Staphylococcus Aureus ◽  
Molecular Docking ◽  
Amino Acid ◽  
Protein A ◽  
New Drugs ◽  
Amino Acid Residues ◽  
Fc Fragment ◽  
Peptide Analog ◽  
Identify Amino Acid ◽  
Starting Point

Over the past decades, molecular docking has become an increasingly popular tool for the development of new drugs. To search and design new compounds, a detailed study of the interaction of existing complexes of ligands with the target protein is necessary. According to the purpose to identify amino acid residues of the B domain of protein A of Staphylococcus aureus involved in interaction with immunoglobulins G, we studied the interaction mechanisms during the formation of a complex of protein A of the Staphylococcus aureus cell wall and immunoglobulins G by molecular docking. By the means of molecular docking we selected four amino acid residues of Phe132, Gln129, Tyr133 and Phe124, which we can use to construct a peptide analog of the active binding site of protein A with the Fc fragment of immunoglobulins G. The obtained results can serve as starting point for an effective strategy for finding new medicines, in particular, they can be used to further develop biospecific sorbent for the selective removal of immunoglobulins G from human blood.

scholarly journals Molecular docking-based test for affinities of two ligands toward vasopressin and oxytocin receptors.

2001 ◽  
Vol 48 (1) ◽  
pp. 131-135 ◽  
Author(s):  
R Slusarz ◽  
R Kaźmierkiewicz ◽  
A Giełdoń ◽  
B Lammek ◽  
J Ciarkowski
Keyword(s):  
Molecular Docking ◽  
Amino Acid ◽  
Ligand Binding ◽  
Effective Procedure ◽  
Amino Acid Residues ◽  
Receptor Ligand ◽  
Docking Simulations ◽  
Oxytocin Receptors ◽  
Developing Area

Molecular docking simulations are now fast developing area of research. In this work we describe an effective procedure of preparation of the receptor-ligand complexes. The amino-acid residues involved in ligand binding were identified and described.

scholarly journals Identification of Antitumor Constituents in Toad Venom by Spectrum-Effect Relationship Analysis and Investigation on Its Pharmacologic Mechanism

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4269
Author(s):  
Ji-Heng Wu ◽  
Yue-Ting Cao ◽  
Hong-Ye Pan ◽  
Long-Hu Wang
Keyword(s):  
Flow Cytometry ◽  
Susceptibility Gene ◽  
In Vitro Assays ◽  
Breast Cancer Susceptibility Gene ◽  
Effect Relationship ◽  
Relationship Analysis ◽  
Effect Model ◽  
Toad Venom ◽  
Spectrum Effect

(1) Background: Toad venom (Bufonis Venenum, known as ‘Chansu’ in Chinese), the secretion of the ear-side gland and skin gland of Bufo gargarizans cantor or Duttaphrynus melanostictus Schneider, has been utilized to treat several diseases in China for thousands of years. However, due to the chemical variability of the components, systematic chemical composition and the key pharmacophores in toad venom have not yet fully understood. Besides, it contains a variety of effective compounds with different physiological activity and chemotypes, mainly including alkaloids, bufogenins, bufotoxins, and so on. The recent pharmacological researches have demonstrated that several bufogenins have remarkable pharmacological effects, such as anti-inflammatory, analgesic effects, and anti-tumor effects. Aim of the study: To identify the bioactive compounds and pharmacophores originating from toad venom based on analyzing spectrum-effect relationship by chemometrics and to explore the anti-cancer mechanism primarily. (2) Materials and methods: Fingerprint of the 21 batches of samples was established using HPLC (High Performance Liquid Chromatography). The anti-tumor activity of extracts were determined by in-vitro assays. Chemometric analysis was used to establish the spectrum-effect model and screen for active ingredients. Pharmacodynamic tests for the screened active compound monomers were conducted with in-vitro assays. Further anti-tumor mechanisms were investigated using western blot and flow cytometry. (3) Results: The established spectrum-effect model has satisfactory fitting effect and predicting accuracy. The inhibitory effect of major screened compounds on lung carcinoma cells A549 were validated in vitro, demonstrating that arenobufagin, telocinobufogenin, and cinobufotalin had significant anti-tumor effects. Through further investigation of the mechanism by western blotting and flow cytometry, we elucidated that arenobufagin induces apoptosis in A549 cells with the enhanced expression of cleaved PARP (poly (ADP-ribose) polymerase). These results may provide valuable information for further structural modification of bufadienolides to treat lung cancer and a method for discovery of anti-tumor active compounds. Conclusions: Our research offers a more scientific method for screening the principal ingredients dominating the pharmacodynamic function. These screened compounds (arenobufagin, etc.) were proven to induce apoptosis by overactivation of the PARP-pathway, which may be utilized to make BRCA (breast cancer susceptibility gene) mutant cancer cells more vulnerable to DNA damaging agents and kill them.

In silico Molecular Docking Analysis Targeting SARS-CoV-2 Spike Protein and Selected Herbal Constituents

2020 ◽  
Vol 14 (suppl 1) ◽  
pp. 989-998 ◽  
Author(s):  
Anbazhagan Subbaiyan ◽  
Karthikeyan Ravichandran ◽  
Shiv Varan Singh ◽  
Muthu Sankar ◽  
Prasad Thomas ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Amino Acid ◽  
Drug Formulation ◽  
Host Cells ◽  
Amino Acid Residues ◽  
Compound I ◽  
Docking Analysis ◽  
S Protein ◽  
Pharmacological Interactions ◽  
Molecular Docking Analysis

In modern drug discovery, molecular docking analysis is routinely used to understand and predict the interaction between a drug molecule and a target protein from a microbe. Drugs identified in this way may inhibit the entry and replication of pathogens in host cells. The SARS-CoV-2 associated coronavirus disease, COVID-19, has become the most contagious and deadly pandemic disease in the world today. In abeyance of any specific vaccine or therapeutic against SARS-CoV-2, the burgeoning situation urges a need for effective drugs to treat the virus-infected patients. Herbal medicines have been used as natural remedies for treating various infectious diseases since ancient times. The spike (S) protein of SARS-CoV-2 is important for the attachment and pathogenesis of the virus. Therefore, this study focused on the search of useful ligands for S protein among active constituents present in common herbs that could serve as efficient remedies for COVID-19. We analysed the binding efficiency of twelve compounds present in common herbs with the S protein of SARS-CoV-2 through molecular docking analysis and also results are validated with two different docking tools. The binding efficiency of ligands was scored based on their predicted pharmacological interactions coupled with binding energy estimates. In docking analysis, compound “I” (Epigallocatechin gallate (EGCG)) was found to have the highest binding affinity with the viral S protein, followed by compounds, “F” (Curcumin),“D” (Apigenin) and “E” (Chrysophanol). The present study corroborates that compound “I” (EGCG) mostly present in the integrants of green tea, shows the highest potentiality for acting as an inhibitor of SARS-CoV-2. Further, characterization of the amino acid residues comprising the viral binding site and the nature of the hydrogen bonding involved in the ligand-receptor interaction revealed significant findings with herbal compound “I” (EGCG) binding to the S protein at eight amino acid residues. The binding sites are situated near to the amino acids which are required for virus pathogenicity. The findings of the present study need in vivo experiments to prove the utility of “I”, “F”,“D” and “E” compounds and their further use in making herb-based anti-SARS-CoV-2 product in near future. This analysis may help to create a new ethno-drug formulation for preventing or curing the COVID-19.

UPLC-MS/MS analysis for antioxidant components of Lycii Fructus based on spectrum-effect relationship

Talanta ◽  
2018 ◽  
Vol 180 ◽  
pp. 389-395 ◽  
Author(s):  
Xian-Fei Zhang ◽  
Juan Chen ◽  
Jun-Li Yang ◽  
Yan-Ping Shi
Keyword(s):  
Effect Relationship ◽  
Ms Analysis ◽  
Spectrum Effect
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