Synthesis and characterization of new imidazolidineiminothione and bis-imidazolidineiminothione derivatives as potential antimicrobial agents

Therapeutic strategies for Covid-19 based on molecular docking and dynamic studies to the ACE-2 receptors, Furin, and viral spike proteins

SARS-CoV-2 is a pandemic virus that caused infections and deaths in many world countries, including the Middle East. The virus-infected human cells by binding via ACE-2 receptor through the Spike protein of the virus with Furin's help causing cell membrane fusion leading to Covid-19-cell entry. No registered drugs or vaccines are triggering this pandemic viral disease yet. Our present work is based on molecular docking and dynamics simulation that performed to spike protein-ACE-2 interface complex, ACE-2 receptor, Spike protein (RBD), and Furin as targets for new small molecules. These drugs target new potential therapies to show their probabilities toward the active sites of mentioned proteins, strongly causing inhibition and/or potential therapy for covid-19. All target proteins were estimated against new target compounds under clinical trials and repurposing drugs currently present. Possibilities of those molecules and potential therapeutics acting on a certain target were predicted. MD simulations over 200 ns with molecular mechanics-generalized Born surface area (MMGBSA) binding energy calculations were performed. The structural and energetic analyses demonstrated the stability of the ligands-M^Pros complex. Our present work will introduce new visions of some biologically active molecules for further studies in-vitro and in-vivo for Covid-19, repurposing of these molecules should be taking place under clinical works and offering different strategies for drugs repurposing against Covid-19 diseases.Communicated by Ramaswamy H. Sarma.

Development of adamantane scaffold containing 1,3,4-thiadiazole derivatives: Design, synthesis, anti-proliferative activity and molecular docking study targeting EGFR

A new series of 1,3,4-thiadiazolo-adamantane derivatives were synthesized through molecular hybridization approach, then used as starting material to synthesize chloro and cyano acetamide-thiadiazole derivatives 2, 3. The newly designed compounds 1-3 were treated with different reagents to design 5-adamantyl thiadiazole derivatives 4-17 and evaluate their in vitro anti-proliferative activity against three cancer cell lines (MCF-7, HepG-2 and A549). Doxorubicin was used as a positive control. The most promising compounds 5, 6, 10a, 10b, 14b, 14c, and 17 showed up-regulation for BAX and down-regulation of Bcl-2, these findings proved their role as hopeful apoptotic inducers. In addition, the inhibitory activity against both wild EGFR^WT and mutant EGFR^L858R-TK for these derivatives revealed that compounds 5, 14c, and 17 have IC₅₀ value ranging from 85 nM to 71.5 nM against wild EGFR^WT and 37.85-41.19 nM against the mutant type, Lapatinib was used as a reference standard with IC₅₀ values of 31.8 nM and 39.53 nM, respectively. The most potent derivatives were subjected to further evaluation against double mutant EGFR ^L858R/T790M and showed good IC₅₀ values between (0.27-0.78 nM) compared to Lapatinib (0.18 nM) and Erlotinib (0.21 nM). Among them, thiazolo-thiadiazole adamantane derivative 17 exhibited the strongest inhibitory activity to the EGFR. Molecular docking studies were performed inside the active site of EGFR (1M17), and binding energy scores ranged between (-19.19 to -22.07 Kcal/mol) compared to Erlotinib (-19.10 Kcal/mol). Furthermore, oral bioavailability beside some pharmacokinetics properties of these derivatives were also investigated in this research work.

Sulfaguanidine Hybrid with Some New Pyridine-2-One Derivatives: Design, Synthesis, and Antimicrobial Activity against Multidrug-Resistant Bacteria as Dual DNA Gyrase and DHFR Inhibitors

Herein, a series of novel hybrid sulfaguanidine moieties, bearing 2-cyanoacrylamide 2a-d, pyridine-2-one 3-10, and 2-imino-2H-chromene-3-carboxamide 11, 12 derivatives, were synthesized, and their structure confirmed by spectral data and elemental analysis. All the synthesized compounds showed moderate to good antimicrobial activity against eight pathogens. The most promising six derivatives, 2a, 2b, 2d, 3a, 8, and 11, revealed to be best in inhibiting bacterial and fungal growth, thus showing bactericidal and fungicidal activity. These derivatives exhibited moderate to potent inhibition against DNA gyrase and DHFR enzymes, with three derivatives 2d, 3a, and 2a demonstrating inhibition of DNA gyrase, with IC₅₀ values of 18.17-23.87 µM, and of DHFR, with IC₅₀ values of 4.33-5.54 µM; their potency is near to that of the positive controls. Further, the six derivatives exhibited immunomodulatory potential and three derivatives, 2d, 8, and 11, were selected for further study and displayed an increase in spleen and thymus weight and enhanced the activation of CD4⁺ and CD8⁺ T lymphocytes. Finally, molecular docking and some AMED studies were performed.

Design, synthesis, in vitro antimicrobial evaluation and molecular docking studies of indol-2-one tagged with morpholinosulfonyl moiety as DNA gyrase inhibitors

A series of Schiff bases 3, 5, 7 and hydrazones 9 were achieved via reaction of 5-(morpholinosulfonyl)indol-2,3-dione (1) with appropriate amines and/or hydrazide derivatives. Representative compounds of the synthesized products were tested and evaluated as antimicrobial agents. According to MIC and MBC results from compounds 9a, 9c, 7a, 3b, 3c, and 5b were able to exhibit significant antibacterial activity against both Gram-positive and Gram-negative bacteria together with moderate antifungal activities. Also, a multi-drug resistance study (MDRS) was carried out to evaluate the activity of most potent compounds, and these compounds showed considerable results compared with Norfloxacin and Tetracycline which observed no results against strains used in this study. The inhibitory activity of most potent compounds (3b, 3c, 5b, 7a, 9a, and 9c) against DNA gyrase isolated from S. aureus was examined. The results indicated that all of these derivatives inhibiting DNA gyrase and therefore lead to separate bacterial DNA and inhibit cell division. Compounds 3b, 9c showed to be very potent inhibitors towards S. aureus DNA gyrase with IC₅₀ values (18.75 ± 1.2 and 19.32 ± 0.99 µM) respectively, compared with Ciprofloxacin (26.43 ± 0.64 µM). Molecular docking studies indicated that the synthesized compounds observed good binding with the enzyme and showed lower binding energy of the most promising compounds than a standard drug used, and enabled a better understanding of their structural features.