scholarly journals Novel 4,6-Disubstituted s-Triazin-2-yl Amino Acid Derivatives as Promising Antifungal Agents

2020 ◽  
Vol 6 (4) ◽  
pp. 237
Author(s):  
Rakia Abd Alhameed ◽  
Zainab Almarhoon ◽  
Essam N. Sholkamy ◽  
Salman Ali Khan ◽  
Zaheer Ul-Haq ◽  
...  
Keyword(s):  
Amino Acid ◽  
Antifungal Activity ◽  
Active Site ◽  
Antifungal Agents ◽  
Docking Studies ◽  
Amino Acid Derivatives ◽  
Active Site Residues ◽  
Standard Drug ◽  
Drug Compounds ◽  
Inhibition Zones

A novel series of 4,6-disubstituted s-triazin-2-yl amino acid derivatives was prepared and characterized. Most of them showed antifungal activity against Candida albicans compared to clotrimazole (standard drug). Compounds bearing aniline derivatives, piperidine and glycine on the triazine core showed the highest inhibition zones at concentrations of 50, 100, 200, and 300 μg per disc. In addition, docking studies revealed that all the compounds accommodated well in the active site residues of N-myristoltransferase (NMT) and exhibited complementarity, which explains the observed antifungal activity. Interestingly, none of these compounds showed antibacterial activity.

Synthesis of New Bis-pyrazolines Endowed with Potent Antifungal Activity against Candida albicans and Aspergillus niger

2020 ◽  
Vol 17 ◽  
Author(s):  
Belgin Sever ◽  
Mehlika Dilek Altıntop ◽  
Ahmet Özdemir
Keyword(s):  
Candida Albicans ◽  
Molecular Docking ◽  
Antifungal Activity ◽  
Aspergillus Niger ◽  
Mtt Assay ◽  
Active Site ◽  
Antifungal Agents ◽  
Docking Studies ◽  
Antifungal Effects ◽  
Nih 3T3

Background: Due to the increasing number of cases of invasive fungal infections (IFIs), there is an urgent need to identify potent antifungal agents capable of combating IFIs. Pyrazolines are one such class of therapeutically active agents that could be considered to fulfil this need. Objective: In this context, this paper aims to identify two new series of bis-pyrazolines endowed with potent antifungal activity against Candida albicans and Aspergillus niger. Methods: Two new series of bis-pyrazolines (4a-i, 5a-e) were synthesized through an efficient and and versatile synthetic procedure. The compounds were screened for their antifungal effects on C. albicans and A. niger using a broth microdilution method. Their cytotoxic effects on NIH/3T3 mouse embryonic fibroblast cell line were determined using MTT assay. Molecular docking studies were performed in the active site of lanosterol 14α-demethylase (CYP51) to shed light on their antifungal effects using Schrödinger’s Maestro molecular modeling package. Results And Discussion: 5,5'-(1,4-Phenylene)bis[1-(2-(5-phenyl-1,3,4-oxadiazol-2-yl)thio)acetyl)-3-(2-thienyl)-4,5- dihydro-1H-pyrazole] (4a) and 5,5'-(1,4-phenylene)bis[1-(2-(4-(2-hydroxyethyl)-1-piperazinylthiocarbamoyl)thio)acetyl)-3- (2-thienyl)-4,5-dihydro-1H-pyrazole] (5a) were found as the most promising antifungal agents in this series. Compounds 4a and 5a showed pronounced antifungal activity against C. albicans (MIC= 0.016 mg/mL) and A. niger (MIC= 0.008 mg/mL). Based on MTT assay, their antifungal effects were selective (IC50 > 0.500 mg/mL for NIH/3T3 cell line). Molecular docking studies suggested that compounds 5a-e might show their anticandidal effects via CYP51 inhibition in regard to their stronger interactions in the active site of CYP51. Conclusion: Compounds 4a and 5a stand out as potential antifungal agents for the management of IFIs caused by C. albicans and A. niger.

scholarly journals Derived amino acid sequence and identification of active site residues of Escherichia coli beta-hydroxydecanoyl thioester dehydrase.

1988 ◽  
Vol 263 (10) ◽  
pp. 4641-4646 ◽  
Author(s):  
J E Cronan ◽  
W B Li ◽  
R Coleman ◽  
M Narasimhan ◽  
D de Mendoza ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Active Site ◽  
Active Site Residues

scholarly journals Synthesis, Molecular Docking Analysis, and Carbonic Anhydrase Inhibitory Evaluations of Benzenesulfonamide Derivatives Containing Thiazolidinone

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2418
Author(s):  
Zuo-Peng Zhang ◽  
Ze-Fa Yin ◽  
Jia-Yue Li ◽  
Zhi-Peng Wang ◽  
Qian-Jie Wu ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Active Site ◽  
Docking Studies ◽  
Active Site Residues ◽  
Single Crystal Diffraction ◽  
Docking Analysis ◽  
X Ray ◽  
Active Site Cavity ◽  
Molecular Docking Analysis ◽  
Positive Controls

To find novel human carbonic anhydrase (hCA) inhibitors, we synthesized thirteen compounds by combining thiazolidinone with benzenesulfonamide. The result of the X-ray single-crystal diffraction experiment confirmed the configuration of this class of compounds. The enzyme inhibition assays against hCA II and IX showed desirable potency profiles, as effective as the positive controls. The docking studies revealed that compounds (2) and (7) efficiently bound in the active site cavity of hCA IX by forming sufficient interactions with active site residues. The fragment of thiazolidinone played an important role in the binding of the molecules to the active site.

scholarly journals Synthesis, Molecular Docking Studies and Antifungal Activity Evaluation of New Thiazolyl-methylen-1,3,4-oxadiazolines as Potential Lanosterol 14a-demethylase Inhibitors

2019 ◽  
Vol 70 (10) ◽  
pp. 3522-3526
Author(s):  
Smaranda Oniga ◽  
Catalin Araniciu ◽  
Gabriel Marc ◽  
Livia Uncu ◽  
Mariana Palage ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Molecular Docking ◽  
Antifungal Activity ◽  
Active Site ◽  
Docking Studies ◽  
Molecular Docking Studies ◽  
Activity Evaluation ◽  
Lanosterol Demethylase ◽  
Target Enzyme

Considering the well-established antifungal activity of azole compounds, a new series of thiazolyl-methylen-1,3,4-oxadiazolines derivatives were designed and synthesized as lanosterol-demethylase inhibitors. The final compounds were screened for antifungal activity against the Candida albicans ATCC 90028 strain. Molecular docking studies were performed to investigate the interaction modes between the compounds and the active site of lanosterol 14a-demethylase, which is a target enzyme for anticandidal azoles. Theoretical ADME predictions were also calculated for the final compounds 5a-h.

Synthesis, characterization and molecular docking studies on some new N-substituted 2-phenylpyrido[2,3-d]pyrimidine derivatives

2021 ◽  
pp. 3846-3854
Author(s):  
Vivek B. Panchabhai ◽  
Santosh R. Butle ◽  
Parag G. Ingole
Keyword(s):  
Crystal Structure ◽  
Antibacterial Activity ◽  
Molecular Docking ◽  
Active Site ◽  
Docking Studies ◽  
Biotin Carboxylase ◽  
Active Site Residues ◽  
Pyrimidine Derivatives ◽  
Molecular Docking Studies ◽  
Novel Scaffold

We report a novel scaffold of N-substituted 2-phenylpyrido(2,3-d)pyrimidine derivatives with potent antibacterial activity by targeting this biotin carboxylase enzyme. The series of eighteen N-substituted 2-phenylpyrido(2,3-d)pyrimidine derivatives were synthesized, characterized and further molecular docking studied to determine the mode of binding and energy changes with the crystal structure of biotin carboxylase (PDB ID: 2V58) was employed as the receptor with compounds 6a-r as ligands. The results obtained from the simulation were obtained in the form of dock score; these values represent the minimum energies. Compounds 6d, 6l, 6n, 6o, 6r and 6i showed formation of hydrogen bonds with the active site residues and van Der Walls interactions with the biotin carboxylase enzyme in their molecular docking studies. This compound can be studied further and developed into a potential antibacterial lead molecule.

SYNTHESIS AND EVALUATION OF SOME SUBSTITUTED 2-AMINOTHIAZOLE DERIVATIVES FOR THEIR ANTITUBERCULAR, ANTIMICROBIAL & ANTIFUNGAL ACTIVITY

INDIAN DRUGS ◽  
2012 ◽  
Vol 49 (01) ◽  
pp. 24-32
Author(s):  
S. R. Pattan ◽  
◽  
S. H Kale ◽  
R. A. Mali ◽  
S. S. Dengale ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Antifungal Agents ◽  
Antitubercular Activity ◽  
Diffusion Method ◽  
Zone Of Inhibition ◽  
Standard Drug ◽  
E Coli ◽  
H Nmr ◽  
Antimicrobial And Antifungal Activity ◽  
Micro Organisms

Millions of people are affected by infectious diseases caused by micro-organisms. Further the widespread microbial resistance had renewed the interest in quest for new antitubercular, antimicrobial & antifungal agents. The present study deals with synthesis & evaluation of some substituted 2-aminothiazole derivatives for their antitubercular, antimicrobial and antifungal activity. 2-aminothiazole derivatives were synthesized by treating substituted acetophenones with thiourea in presence of bromine to give 2-amino 4-substituted phenylthizole and then further treated with chloracetyl chloride to give 2-chloro-N-(4-substituted phenylthizole-2-yl)-acetamide which on refluxing with primary amine gives 15 derivatives. All the synthesized compounds were characterized by IR, H-NMR and elemental analysis.All the synthesized compounds were screened for their antibacterial activity against S. aureus and E. coli by using cup plate agar diffusion method. The activity was measured in terms of zone of inhibition and compared with standard drug ciprofloxacin, sulfonamide. The aminothiazole derivatives were evaluated for antitubercular activity and their result were compared with standard streptomycin.

scholarly journals The Uncommon Active Site of D-Amino Acid Transaminase from Haliscomenobacter hydrossis: Biochemical and Structural Insights into the New Enzyme

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 5053
Author(s):  
Alina K. Bakunova ◽  
Alena Yu. Nikolaeva ◽  
Tatiana V. Rakitina ◽  
Tatiana Y. Isaikina ◽  
Maria G. Khrenova ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Structural Analysis ◽  
Active Site ◽  
Active Sites ◽  
Structural Basis ◽  
Active Site Residues ◽  
Type Iv ◽  
Fold Type ◽  
Arginine Residues

Among industrially important pyridoxal-5’-phosphate (PLP)-dependent transaminases of fold type IV D-amino acid transaminases are the least studied. However, the development of cascade enzymatic processes, including the synthesis of D-amino acids, renewed interest in their study. Here, we describe the identification, biochemical and structural characterization of a new D-amino acid transaminase from Haliscomenobacter hydrossis (Halhy). The new enzyme is strictly specific towards D-amino acids and their keto analogs; it demonstrates one of the highest rates of transamination between D-glutamate and pyruvate. We obtained the crystal structure of the Halhy in the holo form with the protonated Schiff base formed by the K143 and the PLP. Structural analysis revealed a novel set of the active site residues that differ from the key residues forming the active sites of the previously studied D-amino acids transaminases. The active site of Halhy includes three arginine residues, one of which is unique among studied transaminases. We identified critical residues for the Halhy catalytic activity and suggested functions of the arginine residues based on the comparative structural analysis, mutagenesis, and molecular modeling simulations. We suggested a strong positive charge in the O-pocket and the unshaped P-pocket as a structural code for the D-amino acid specificity among transaminases of PLP fold type IV. Characteristics of Halhy complement our knowledge of the structural basis of substrate specificity of D-amino acid transaminases and the sequence-structure-function relationships in these enzymes.

scholarly journals PREMONITION - Preprocessing motifs in protein structures for search acceleration

F1000Research ◽  
2014 ◽  
Vol 3 ◽  
pp. 217 ◽  
Author(s):  
Sandeep Chakraborty ◽  
Basuthkar J. Rao ◽  
Bjarni Asgeirsson ◽  
Ravindra Venkatramani ◽  
Abhaya M. Dandekar
Keyword(s):  
Protein Structure ◽  
Amino Acid ◽  
Active Site ◽  
Active Sites ◽  
Protein Structures ◽  
3D Structure ◽  
Search Space ◽  
Computational Method ◽  
Computational Time ◽  
Active Site Residues

The remarkable diversity in biological systems is rooted in the ability of the twenty naturally occurring amino acids to perform multifarious catalytic functions by creating unique structural scaffolds known as the active site. Finding such structrual motifs within the protein structure is a key aspect of many computational methods. The algorithm for obtaining combinations of motifs of a certain length, although polynomial in complexity, runs in non-trivial computer time. Also, the search space expands considerably if stereochemically equivalent residues are allowed to replace an amino acid in the motif. In the present work, we propose a method to precompile all possible motifs comprising of a set (n=4 in this case) of predefined amino acid residues from a protein structure that occur within a specified distance (R) of each other (PREMONITION). PREMONITION rolls a sphere of radius R along the protein fold centered at the C atom of each residue, and all possible motifs are extracted within this sphere. The number of residues that can occur within a sphere centered around a residue is bounded by physical constraints, thus setting an upper limit on the processing times. After such a pre-compilation step, the computational time required for querying a protein structure with multiple motifs is considerably reduced. Previously, we had proposed a computational method to estimate the promiscuity of proteins with known active site residues and 3D structure using a database of known active sites in proteins (CSA) by querying each protein with the active site motif of every other residue. The runtimes for such a comparison is reduced from days to hours using the PREMONITION methodology.

scholarly journals Synthesis and Molecular Docking Studies of some Pyrano[2,3-c] Pyrazole as an Inhibitor of SARS-Coronavirus 3CL Protease

2021 ◽  
Vol 11 (3) ◽  
pp. 3780-3801
Keyword(s):  
Molecular Docking ◽  
Active Site ◽  
Antiviral Treatment ◽  
Specific Treatment ◽  
Docking Studies ◽  
Strong Hydrogen Bond ◽  
Active Site Residues ◽  
Hydrogen Bond Interaction ◽  
Main Protease ◽  
3Cl Protease

The widespread global COVID-19 pandemic due to the lack of specific treatment and the urgent situation requires the use of all resources to remedy this scourge. The current study aimed to use molecular docking tools to find potential drug candidates for treatment. The pyrano[2,3-c] pyrazole 5(a-e) was targeted against the Main protease (Mpro), which plays a vital role in the replication and transcription of the Corona viral genome. The 3CL Protease (PDB ID 6LU7) was modeled, and the compounds were docked using Autodock Vina software, and ADMET data have been studied. All synthesized compounds were well engaged into the active site of the main protease with strong hydrogen bond interaction and a good score of energy. The 5b have been classed as the best inhibitor with an energy score of -6.2 kcal/mol, similar to the one given by chloroquine (-6.2Kcal/mol). Moreover, the molecular interaction studies showed that protease structure had multiple active site residues for all studied compounds. Our finding confirms the potential of these derivatives as lead compounds against the selected target protein of coronavirus, which needs further analysis and dynamic simulation studies to propose then develop a new antiviral treatment.

scholarly journals Optimization Rules for SARS-CoV-2 Mpro Antivirals: Ensemble Docking and Exploration of the Coronavirus Protease Active Site

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 942 ◽  
Author(s):  
Shana V. Stoddard ◽  
Serena D. Stoddard ◽  
Benjamin K. Oelkers ◽  
Kennedi Fitts ◽  
Kellen Whalum ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Active Site ◽  
Viral Infections ◽  
Data Bank ◽  
Docking Studies ◽  
Design Guidelines ◽  
Hydrogen Binding ◽  
Drug Candidates ◽  
Ensemble Docking ◽  
Drug Compounds

Coronaviruses are viral infections that have a significant ability to impact human health. Coronaviruses have produced two pandemics and one epidemic in the last two decades. The current pandemic has created a worldwide catastrophe threatening the lives of over 15 million as of July 2020. Current research efforts have been focused on producing a vaccine or repurposing current drug compounds to develop a therapeutic. There is, however, a need to study the active site preferences of relevant targets, such as the SARS-CoV-2 main protease (SARS-CoV-2 Mpro), to determine ways to optimize these drug compounds. The ensemble docking and characterization work described in this article demonstrates the multifaceted features of the SARS-CoV-2 Mpro active site, molecular guidelines to improving binding affinity, and ultimately the optimization of drug candidates. A total of 220 compounds were docked into both the 5R7Z and 6LU7 SARS-CoV-2 Mpro crystal structures. Several key preferences for strong binding to the four subsites (S1, S1′, S2, and S4) were identified, such as accessing hydrogen binding hotspots, hydrophobic patches, and utilization of primarily aliphatic instead of aromatic substituents. After optimization efforts using the design guidelines developed from the molecular docking studies, the average docking score of the parent compounds was improved by 6.59 −log10(Kd) in binding affinity which represents an increase of greater than six orders of magnitude. Using the optimization guidelines, the SARS-CoV-2 Mpro inhibitor cinanserin was optimized resulting in an increase in binding affinity of 4.59 −log10(Kd) and increased protease inhibitor bioactivity. The results of molecular dynamic (MD) simulation of cinanserin-optimized compounds CM02, CM06, and CM07 revealed that CM02 and CM06 fit well into the active site of SARS-CoV-2 Mpro [Protein Data Bank (PDB) accession number 6LU7] and formed strong and stable interactions with the key residues, Ser-144, His-163, and Glu-166. The enhanced binding affinity produced demonstrates the utility of the design guidelines described. The work described herein will assist scientists in developing potent COVID-19 antivirals.

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