scholarly journals Cheminformatics Modeling of Closantel Analogues for Treating River Blindness

2020 ◽  
Author(s):  
Melaine A. Kuenemann ◽  
Phyo Phyo Zin ◽  
Sravya Kuchibhotla ◽  
Denis Fourches
Keyword(s):  
Active Site ◽  
Structural Changes ◽  
Parasitic Nematode ◽  
Chemical Space ◽  
Therapeutic Agents ◽  
Binding Modes ◽  
River Blindness ◽  
Structure Activity ◽  
Potential Binding ◽  
Biological Target

<p></p><p>Onchocerciasis (also known as river blindness<i>)</i> is a neglected tropical disease caused by the <i>Onchocerca volvulus</i> parasitic nematode. Currently, the only approved drug for treating this disease is ivermectin, which is a broad-spectrum antiparasitic agent. However, signs of resistance towards ivermectin have started to emerge. New therapeutic agents are thus urgently needed. The OvCHT1 chitinase enzyme from <i>O. volvulus</i> has been established as a relevant biological target for combatting river blindness. The veterinary anthelmintic drug closantel has been found to be a potent, micro-molar OvCHT1 inhibitor. Herein, we investigated the chemical space of closantel and all its synthesized analogues, focusing on the analysis of their potential binding modes towards OvCHT1. First, we conducted an unsupervised hierarchical clustering to group highly similar analogues and explore structure-activity relationships. Second, we conducted a structure-based molecular docking to predict and study the binding modes of all 57 closantel analogues in the active site of OvCHT1. Third, we screened more than 4 million lead-like compounds from the ZINC library to identify other structurally similar ligands that could potentially bind to OvCHT1. The cheminformatics analysis of the closantel analogues illustrated how minor structural changes in closantel analogues can impact their OvCHT1 activity.</p><p></p>

scholarly journals Cheminformatics Modeling of Closantel Analogues for Treating River Blindness

2020 ◽  
Author(s):  
Melaine A. Kuenemann ◽  
Phyo Phyo Zin ◽  
Sravya Kuchibhotla ◽  
Denis Fourches
Keyword(s):  
Active Site ◽  
Structural Changes ◽  
Parasitic Nematode ◽  
Chemical Space ◽  
Therapeutic Agents ◽  
Binding Modes ◽  
River Blindness ◽  
Structure Activity ◽  
Potential Binding ◽  
Biological Target

<p></p><p>Onchocerciasis (also known as river blindness<i>)</i> is a neglected tropical disease caused by the <i>Onchocerca volvulus</i> parasitic nematode. Currently, the only approved drug for treating this disease is ivermectin, which is a broad-spectrum antiparasitic agent. However, signs of resistance towards ivermectin have started to emerge. New therapeutic agents are thus urgently needed. The OvCHT1 chitinase enzyme from <i>O. volvulus</i> has been established as a relevant biological target for combatting river blindness. The veterinary anthelmintic drug closantel has been found to be a potent, micro-molar OvCHT1 inhibitor. Herein, we investigated the chemical space of closantel and all its synthesized analogues, focusing on the analysis of their potential binding modes towards OvCHT1. First, we conducted an unsupervised hierarchical clustering to group highly similar analogues and explore structure-activity relationships. Second, we conducted a structure-based molecular docking to predict and study the binding modes of all 57 closantel analogues in the active site of OvCHT1. Third, we screened more than 4 million lead-like compounds from the ZINC library to identify other structurally similar ligands that could potentially bind to OvCHT1. The cheminformatics analysis of the closantel analogues illustrated how minor structural changes in closantel analogues can impact their OvCHT1 activity.</p><p></p>

Metal-, and Organocatalyst-Free One-Pot Assembly of Chiral Aza-Tricyclic Molecules: Creating Six Contiguous Stereocenters from 2-D-Structures and an Amino Acid

2020 ◽  
Author(s):  
Dung Do
Keyword(s):  
Amino Acid ◽  
Chemical Space ◽  
Structural Diversity ◽  
Therapeutic Agents ◽  
Chiral Molecules ◽  
One Pot ◽  
Complex Molecules ◽  
Chiral Catalyst ◽  
Chiral Complex ◽  
Free Process

<p>Chiral molecules with their defined 3-D structures are of paramount importance for the study of chemical biology and drug discovery. Having rich structural diversity and unique stereoisomerism, chiral molecules offer a large chemical space that can be explored for the design of new therapeutic agents.<sup>1</sup> Practically, chiral architectures are usually prepared from organometallic and organocatalytic processes where a transition metal or an organocatalyst is tailor-made for desired reactions. As a result, developing a method that enables rapid assembly of chiral complex molecules under metal- and organocatalyst-free condition represents a daunting challenge. Here we developed a straightforward route to create a chiral 3-D structure from 2-D structures and an amino acid without any chiral catalyst. The center of this research is the design of a <a>special chiral spiroimidazolidinone cyclohexadienone intermediate</a>, a merger of a chiral reactive substrate with multiple nucleophillic/electrophillic sites and a transient organocatalyst. <a>This unique substrate-catalyst (“subcatalyst”) dual role of the intermediate enhances </a><a>the coordinational proximity of the chiral substrate and catalyst</a> in the key Aza-Michael/Michael cascade resulting in a substantial steric discrimination and an excellent overall diastereoselectivity. Whereas the “subcatalyst” (hidden catalyst) is not present in the reaction’s initial components, which renders a chiral catalyst-free process, it is strategically produced to promote sequential self-catalyzed reactions. The success of this methodology will pave the way for many efficient preparations of chiral complex molecules and aid for the quest to create next generation of therapeutic agents.</p>

Applications of Quantitative Structure-Activity Relationships (QSAR) based Virtual Screening in Drug Design: A Review

2020 ◽  
Vol 20 (14) ◽  
pp. 1375-1388 ◽  
Author(s):  
Patnala Ganga Raju Achary
Keyword(s):  
Machine Learning ◽  
Drug Discovery ◽  
Virtual Screening ◽  
Model Building ◽  
Chemical Space ◽  
Qsar Model ◽  
Quantitative Structure ◽  
Efficient Manner ◽  
Qsar Analysis ◽  
Structure Activity

The scientists, and the researchers around the globe generate tremendous amount of information everyday; for instance, so far more than 74 million molecules are registered in Chemical Abstract Services. According to a recent study, at present we have around 1060 molecules, which are classified as new drug-like molecules. The library of such molecules is now considered as ‘dark chemical space’ or ‘dark chemistry.’ Now, in order to explore such hidden molecules scientifically, a good number of live and updated databases (protein, cell, tissues, structure, drugs, etc.) are available today. The synchronization of the three different sciences: ‘genomics’, proteomics and ‘in-silico simulation’ will revolutionize the process of drug discovery. The screening of a sizable number of drugs like molecules is a challenge and it must be treated in an efficient manner. Virtual screening (VS) is an important computational tool in the drug discovery process; however, experimental verification of the drugs also equally important for the drug development process. The quantitative structure-activity relationship (QSAR) analysis is one of the machine learning technique, which is extensively used in VS techniques. QSAR is well-known for its high and fast throughput screening with a satisfactory hit rate. The QSAR model building involves (i) chemo-genomics data collection from a database or literature (ii) Calculation of right descriptors from molecular representation (iii) establishing a relationship (model) between biological activity and the selected descriptors (iv) application of QSAR model to predict the biological property for the molecules. All the hits obtained by the VS technique needs to be experimentally verified. The present mini-review highlights: the web-based machine learning tools, the role of QSAR in VS techniques, successful applications of QSAR based VS leading to the drug discovery and advantages and challenges of QSAR.

scholarly journals Multi-Targeting Bioactive Compounds Extracted from Essential Oils as Kinase Inhibitors

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2174 ◽  
Author(s):  
Annalisa Maruca ◽  
Delia Lanzillotta ◽  
Roberta Rocca ◽  
Antonio Lupia ◽  
Giosuè Costa ◽  
...  
Keyword(s):  
Essential Oils ◽  
Binding Affinity ◽  
Structural Changes ◽  
Kinase Inhibitors ◽  
Synergistic Effects ◽  
Data Bank ◽  
Binding Modes ◽  
Starting Point ◽  
Target Action ◽  
Potential Resource

Essential oils (EOs) are popular in aromatherapy, a branch of alternative medicine that claims their curative effects. Moreover, several studies reported EOs as potential anti-cancer agents by inducing apoptosis in different cancer cell models. In this study, we have considered EOs as a potential resource of new kinase inhibitors with a polypharmacological profile. On the other hand, computational methods offer the possibility to predict the theoretical activity profile of ligands, discovering dangerous off-targets and/or synergistic effects due to the potential multi-target action. With this aim, we performed a Structure-Based Virtual Screening (SBVS) against X-ray models of several protein kinases selected from the Protein Data Bank (PDB) by using a chemoinformatics database of EOs. By evaluating theoretical binding affinity, 13 molecules were detected among EOs as new potential kinase inhibitors with a multi-target profile. The two compounds with higher percentages in the EOs were studied more in depth by means Induced Fit Docking (IFD) protocol, in order to better predict their binding modes taking into account also structural changes in the receptor. Finally, given its good binding affinity towards five different kinases, cinnamyl cinnamate was biologically tested on different cell lines with the aim to verify the antiproliferative activity. Thus, this work represents a starting point for the optimization of the most promising EOs structure as kinase inhibitors with multi-target features.

scholarly journals Discovery of New Inhibitors of Transforming Growth Factor-Beta Type 1 Receptor by Utilizing Docking and Structure-Activity Relationship Analysis

2019 ◽  
Vol 20 (17) ◽  
pp. 4090 ◽  
Author(s):  
Jiang ◽  
Deng
Keyword(s):  
Molecular Docking ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Binding Modes ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Growth Factor Beta ◽  
New Compounds

The transforming growth factor-beta (TGF-β) plays an important role in pathological fibrosis and cancer transformation. Therefore, the inhibition of the TGF-β signaling pathway has therapeutic potential in the treatment of cancer. In this study, the binding modes between 47 molecules with a pyrrolotriazine-like backbone structure and transforming growth factor-beta type 1 receptor (TβR1) were simulated by molecular docking using Discovery Studio software, and their structure–activity relationships were analyzed. On the basis of the analysis of the binding modes of ligands in the active site and the structure–activity relationships, 29,254 new compounds were designed for virtual screening. According to the aforementioned analyses and Lipinski’s rule of five, five new compounds (CQMU1901–1905) with potential activity were screened through molecular docking. Among them, CQMU1905 is an attractive molecule composed of 5-fluorouracil (5-FU), 6-mercaptopurine (6-MP), and 5-azacytosine. Interestingly, 5-FU, 6-MP, and 5-azacytidine are often used as anti-metabolic agents in cancer treatment. Compared with existing compounds, CQMU1901–1905 can interact with target proteins more effectively and have good potential for modification, making them worthy of further study.

scholarly journals Flavonoids from the Genus Euphorbia: Isolation, Structure, Pharmacological Activities and Structure–Activity Relationships

2021 ◽  
Vol 14 (5) ◽  
pp. 428
Author(s):  
Douglas Kemboi Magozwi ◽  
Mmabatho Dinala ◽  
Nthabiseng Mokwana ◽  
Xavier Siwe-Noundou ◽  
Rui W. M. Krause ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Antioxidant Properties ◽  
Structure Activity Relationship ◽  
Biological Properties ◽  
Therapeutic Agents ◽  
Skeletal Structure ◽  
Activity Relationship ◽  
Hydroxyl Groups ◽  
Structure Activity ◽  
Review Reports

Plants of the genus Euphorbia are widely distributed across temperate, tropical and subtropical regions of South America, Asia and Africa with established Ayurvedic, Chinese and Malay ethnomedical records. The present review reports the isolation, occurrence, phytochemistry, biological properties, therapeutic potential and structure–activity relationship of Euphorbia flavonoids for the period covering 2000–2020, while identifying potential areas for future studies aimed at development of new therapeutic agents from these plants. The findings suggest that the extracts and isolated flavonoids possess anticancer, antiproliferative, antimalarial, antibacterial, anti-venom, anti-inflammatory, anti-hepatitis and antioxidant properties and have different mechanisms of action against cancer cells. Of the investigated species, over 80 different types of flavonoids have been isolated to date. Most of the isolated flavonoids were flavonols and comprised simple O-substitution patterns, C-methylation and prenylation. Others had a glycoside, glycosidic linkages and a carbohydrate attached at either C-3 or C-7, and were designated as d-glucose, l-rhamnose or glucorhamnose. The structure–activity relationship studies showed that methylation of the hydroxyl groups on C-3 or C-7 reduces the activities while glycosylation loses the activity and that the parent skeletal structure is essential in retaining the activity. These constituents can therefore offer potential alternative scaffolds towards development of new Euphorbia-based therapeutic agents.

scholarly journals The Influence of Varying Fluorination Patterns on the Thermodynamics and Kinetics of Benzenesulfonamide Binding to Human Carbonic Anhydrase II

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 509 ◽  
Author(s):  
Steffen Glöckner ◽  
Khang Ngo ◽  
Björn Wagner ◽  
Andreas Heine ◽  
Gerhard Klebe
Keyword(s):  
Carbonic Anhydrase ◽  
Carbonic Anhydrase Ii ◽  
The Novel ◽  
Binding Modes ◽  
X Ray ◽  
Structure Activity ◽  
Small Set ◽  
Novel Method ◽  
Human Carbonic Anhydrase ◽  
Kinetics Of

The fluorination of lead-like compounds is a common tool in medicinal chemistry to alter molecular properties in various ways and with different goals. We herein present a detailed study of the binding of fluorinated benzenesulfonamides to human Carbonic Anhydrase II by complementing macromolecular X-ray crystallographic observations with thermodynamic and kinetic data collected with the novel method of kinITC. Our findings comprise so far unknown alternative binding modes in the crystalline state for some of the investigated compounds as well as complex thermodynamic and kinetic structure-activity relationships. They suggest that fluorination of the benzenesulfonamide core is especially advantageous in one position with respect to the kinetic signatures of binding and that a higher degree of fluorination does not necessarily provide for a higher affinity or more favorable kinetic binding profiles. Lastly, we propose a relationship between the kinetics of binding and ligand acidity based on a small set of compounds with similar substitution patterns.

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