Design, Synthesis, Antimicrobial and Anti-biofilm Evaluation, and Molecular Docking of Newly Substituted Fluoroquinazolinones

2019 ◽  
Vol 15 (6) ◽  
pp. 659-675
Author(s):  
Mohamed F. Zayed ◽  
Sabrin R.M. Ibrahim ◽  
EL-Sayed E. Habib ◽  
Memy H. Hassan ◽  
Sahar Ahmed ◽  
...  

Background: Quinazolines and quinazolinones derivatives are well known for their important range of therapeutic activities. Objective: The study aims to carry out the synthesis of some derivatives of substituted fluoroquinazolinones based on structure-based design and evaluation of their antibacterial, antifungal, and anti-biofilm activities. Methods: Compounds were chemically synthesized by conventional methods. Structures were established on the basis of spectral and elemental analyses. The antimicrobial potential was tested against various microorganisms using the agar disc-diffusion method. MIC and MBC as well as anti-biofilm activity for the highly active compounds were assessed. Moreover, the computational studies were performed using Auto dock free software package (version 4.0) to explain the predicted mode of binding. Results: All derivatives (5-8), (10a-g), and (A-H) were biologically tested and showed significant antimicrobial activity comparable to the reference compounds. Compounds 10b, 10c, and 10d had a good MIC and MBC against Gram-positive bacteria, whereas 10b and 10d showed significant MIC and MBC against Gram-negative bacteria. However, compounds E and F exhibited good MIC and MBC against fungi. Compound 10c and 8 exhibited significant anti-biofilm activity towards S. aureus and M. luteus. Molecular docking study revealed a strong binding of these derivatives with their receptor-site and detected their predicted mode of binding. Conclusion: The synthesized derivatives showed promising antibacterial, antifungal, and antibiofilm activities. Modeling study explained their binding mode and showed strong binding affinity with their receptor-site. The highly active compounds 5 and 10c could be subjected to future optimization and investigation to be effective antimicrobial agents.

JSMARTech ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. 028-034
Author(s):  
Rachmawati Ardiana ◽  
◽  
Dewi Uswatun Khasanah ◽  
Diah Permatasari ◽  
Oktavia Rahayu Adianingsih ◽  
...  

2019 ◽  
Vol 88 ◽  
pp. 102934 ◽  
Author(s):  
Omaima G. Shaaban ◽  
Doaa A.E. Issa ◽  
Alaa A. El-Tombary ◽  
Shrouk M. Abd El Wahab ◽  
Abeer E. Abdel Wahab ◽  
...  

2020 ◽  
Vol 18 (3) ◽  
pp. 306-314 ◽  
Author(s):  
Nisheeth C. Desai ◽  
Darshita V. Vaja ◽  
Krunalsinh A. Jadeja ◽  
Surbhi B. Joshi ◽  
Vijay M. Khedkar

Introduction: In continuation of our efforts to find new antimicrobials, herein we report the synthesis of various pyrazole, pyrazoline, and pyridine based novel bioactive heterocycles (3a-t). Methods: Newly synthesized compounds were analysed for their antimicrobial activity. Compounds 3c, 3h, 3i, 3k, 3n, and 3q showed significant antimicrobial activity. Results: Molecular docking study for the most active analogues against DNA gyrase subunit b (PDB ID: 1KZN) corroborated well with the observed antimicrobial potency exhibiting significant binding affinity. Conclusion: Interpretation of the chemical structures reported in this paper was based on IR, 1H NMR, 13C NMR, and mass spectral data.


Author(s):  
Seyithan Taysi ◽  
Firas Shawqi Algburi ◽  
Zaid Mohammed ◽  
Omeed Akbar Ali ◽  
Muhammed Enes Taysi

Widely consumed worldwide, Nigella sativa (NS) is a medicinal herb commonly used in various alternative medicine systems such as Unani and Tibb, Ayurveda, and Siddha. Recommended for regular use in Tibb-e-Nabwi (Prophetic Medicine), NS is considered one of the most notable forms of healing medicine in Islamic literature. Thymoquinone (TQ), the main component of the essential oil of NS, has been reported to have many properties such as antioxidant, anti-inflammatory, antiviral, and antineoplastic. Its chemical structure indicates antiviral potential against many viruses, including the hepatitis C virus, human immunodeficiency virus, and other coronavirus diseases. Interestingly, molecular docking studies have demonstrated that TQ can potentially inhibit the development of the coronavirus disease 2019 (COVID-19) by binding to the receptor site on the transmembrane serine proteinase 2 (the activator enzyme that attaches the virus to the cell). In addition, TQ has been shown to be effective against cancer cells due to its inhibitory effect by binding to the different regions of MDM2, according to the proposed molecular docking study. Detailed in this review is the origin of TQ, its significance in alternative medicine, pharmacological value, potential as a cancer anti-proliferative agent, use against the coronavirus disease 2019 (COVID-19), and treatment of other diseases.


2019 ◽  
Vol 15 (7) ◽  
pp. 813-832 ◽  
Author(s):  
Sunil Harer ◽  
Manish Bhatia ◽  
Vikram Kawade

Background: Dihydrofolate reductase is one of the important enzymes for thymidylate and purine synthesis in micro-organisms. A large number of drugs have been designed to inhibit microbial DHFR but over the period of time, some drugs have developed resistance and cross reactivity towards the enzyme. Over the past few decades, benzimidazoles, triazoles and their derivatives have been grabbing the attention of the synthetic chemists for their wide gamut of antibacterial and antifungal activities targeting microbial protein DHFR. Objective: Our goal behind present investigation is to explore benzimidazoles class of drugs as microbial DHFR inhibitors by studying ligand-receptor binding interactions, in vitro enzyme inhibition assay and confirmation of anti-microbial activity against selected pathogenic microorganisms. Methods: A library containing thirty novel 2,6-disubstituted 1H-benzimidazoles was synthesized by one pot condensation of o-nitro aniline or 2,4-dinitro aniline with series of aldehydes or acetophenones using Na2S2O4 or SnCl2 respectively and reflux for 5-6hr. Structures of compounds have been confirmed by spectroscopic methods as 1H and 13C NMR, FT-IR and MS. In vitro DHFR inhibition study was performed by using Epoch microplate reader and IC50 of the test compounds was compared with Trimethoprim. In vitro antimicrobial activity was performed against selected clinical pathogens by agar disk diffusion method and MIC (µg/mL) was reported. Results: Moderate to good level of DHFR inhibition was observed with IC50 values in the range of 7-23 µM. Compounds B1, B19, B22, B24 and B30 expressed 1.1 to 1.4 folds more prominent DHFR inhibitory activity as compared to standard Trimethoprim. Remarkable antimicrobial activity was exhibited by B1, B19, B22, B24 and B30. Molecular docking study revealed perfect binding of test ligands with key amino acids of DHFR as Phe31, Ile94, Ile5, Asp27, Gln32 and Phe36. Conclusion: Nature of 1H-benzimidazole substituents at position 2 and 6 had influence over magnitude and type of molecular binding and variation in the biological activity. The present series of 1H-benzimidazoles could be considered promising broad-spectrum antimicrobial candidates that deserve in future for preclinical antimicrobial evaluation and development of newer antimicrobial agents targeting microbial DHFR.


2019 ◽  
Vol 92 ◽  
pp. 103217 ◽  
Author(s):  
Mahadev Patil ◽  
Anurag Noonikara Poyil ◽  
Shrinivas D. Joshi ◽  
Shivaputra A. Patil ◽  
Siddappa A. Patil ◽  
...  

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