Browsing by Author "Novak, Jurica"

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Design, one-pot synthesis, computational and biological evaluation of diaryl benzimidazole derivatives as MEK inhibitors
(Taylor and Francis Ltd., 2023-10-09T00:00:00) Ram, Teja; Singh, Ankit Kumar; Pathak, Prateek; Kumar, Adarsh; Singh, Harshwardhan; Grishina, Maria; Novak, Jurica; Kumar, Pradeep
MEK mutations are more common in various human malignancies, such as pancreatic cancer (70�90%), mock melanoma (50%), liver cancer (20�40%), colorectal cancer (25�35%), melanoma (15�20%), non-small cell lung cancer (10�20%) and basal breast cancer (1�5%). Considering the significance of MEK mutations in diverse cancer types, the rational design of the proposed compounds relies on the structural resemblance to FDA-approved MEK inhibitors like selumetinib and binimetinib. The compound under design features distinct substitutions at the benzimidazole moiety, specifically at positions 2 and 3, akin to the FDA-approved drugs, albeit differing in positions 5 and 6. Subsequent structural refinement was guided by key elements including the DFG motif, hydrophobic pocket and catalytic loop of the MEK protein. A set of 15 diverse diaryl benzimidazole derivatives (S1�S15) were synthesized via a one-pot approach and characterized through spectroscopic techniques, including MASS, IR, 1H NMR and 13C NMR. In vitro anticancer activities of all the synthesized compounds were evaluated against four cancer cell lines, A375, HT ?29, A431 and HFF, along with the standard drug trametinib. Molecular docking was performed for all synthesized compounds (S1�15), followed by 950 ns molecular dynamics simulation studies for the promising compounds S1, S5 and S15. The stability of these complexes was assessed by calculating the root-mean-square deviation, solvent accessible surface area and gyration radius relative to their parent structures. Additionally, free energy of binding calculations were performed. Based on the biological and computational results, S15 was the most potent compound and S1 and S5 are comparable to the standard drug trametinib. Communicated by Ramaswamy H. Sarma. � 2023 Informa UK Limited, trading as Taylor & Francis Group.
Gaussian field-based 3D-QSAR and molecular simulation studies to design potent pyrimidine-sulfonamide hybrids as selective BRAFV600E inhibitors
(Royal Society of Chemistry, 2022-10-21T00:00:00) Singh, Ankit Kumar; Novak, Jurica; Kumar, Adarsh; Singh, Harshwardhan; Thareja, Suresh; Pathak, Prateek; Grishina, Maria; Verma, Amita; Yadav, Jagat Pal; Khalilullah, Habibullah; Pathania, Vikas; Nandanwar, Hemraj; Jaremko, Mariusz; Emwas, Abdul-Hamid; Kumar, Pradeep
The �RAS-RAF-MEK-ERK� pathway is an important signaling pathway in melanoma. BRAFV600E (70-90%) is the most common mutation in this pathway. BRAF inhibitors have four types of conformers: type I (?C-IN/DFG-IN), type II (?C-IN/DFG-OUT), type I1/2 (?C-OUT/DFG-IN), and type I/II (?C-OUT/DFG-OUT). First- and second-generation BRAF inhibitors show resistance to BRAFV600E and are ineffective against malignancies induced by dimer BRAF mutants causing �paradoxical� activation. In the present study, we performed molecular modeling of pyrimidine-sulfonamide hybrids inhibitors using 3D-QSAR, molecular docking, and molecular dynamics simulations. Previous reports reveal the importance of pyrimidine and sulfonamide moieties in the development of BRAFV600E inhibitors. Analysis of 3D-QSAR models provided novel pyrimidine sulfonamide hybrid BRAFV600E inhibitors. The designed compounds share similarities with several structural moieties present in first- and second-generation BRAF inhibitors. A total library of 88 designed compounds was generated and molecular docking studies were performed with them. Four molecules (T109, T183, T160, and T126) were identified as hits and selected for detailed studies. Molecular dynamics simulations were performed at 900 ns and binding was calculated. Based on molecular docking and simulation studies, it was found that the designed compounds have better interactions with the core active site [the nucleotide (ADP or ATP) binding site, DFG motif, and the phospho-acceptor site (activation segment) of BRAFV600E protein than previous inhibitors. Similar to the FDA-approved BRAFV600E inhibitors the developed compounds have [?C-OUT/DFG-IN] conformation. Compounds T126, T160 and T183 interacted with DIF (Leu505), making them potentially useful against BRAFV600E resistance and malignancies induced by dimer BRAF mutants. The synthesis and biological evaluation of the designed molecules is in progress, which may lead to some potent BRAFV600E selective inhibitors. � 2022 The Royal Society of Chemistry.
Virtual screening, structure based pharmacophore mapping, and molecular simulation studies of pyrido[2,3-d]pyrimidines as selective thymidylate synthase inhibitors
(Taylor and Francis Ltd., 2023-05-08T00:00:00) Kumar, Adarsh; Novak, Jurica; Singh, Ankit Kumar; Singh, Harshwardhan; Thareja, Suresh; Pathak, Prateek; Grishina, Maria; Verma, Amita; Kumar, Pradeep
Human thymidylate synthase is the rate-limiting enzyme in the de novo synthesis of 2'-deoxythymidine-5'-monophosphate. dUMP (pyrimidine) and folate binding site hTS inhibitors showed resistance in colorectal cancer (CRC). In the present study, we have performed virtual screening of the pyrido[2,3-d]pyrimidine database, followed by binding free energy calculations, and pharmacophore mapping to design novel pyrido[2,3-d]pyrimidine derivatives to stabilize inactive confirmation of hTS. A library of 42 molecules was designed. Based on the molecular docking studies, four ligands (T36, T39, T40, and T13) were identified to have better interactions and docking scores with the catalytic sites [dUMP (pyrimidine) and folate binding sites] of hTS protein than standard drug, raltitrexed. To validate efficacy of the designed molecules, we performed molecular dynamics simulation studies at 1000 ns with principal component analysis and binding free energy calculations on the hTS protein, also drug likeness properties of all hits were in acceptable range. Compounds T36, T39, T40, and T13 interacted with the catalytic amino acid (Cys195), an essential amino acid for anticancer activity. The designed molecules stabilized the inactive conformation of hTS, resulting in the inhibition of hTS. The designed compounds will undergo synthesis and biological evaluation, which may yield selective, less toxic, and highly potent hTS inhibitors. Communicated by Ramaswamy H. Sarma. � 2023 Informa UK Limited, trading as Taylor & Francis Group.