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The pandemic caused by novel coronavirus disease 2019 infecting millions of populations worldwide and counting, has demanded quick and potential therapeutic strategies. Current approved drugs or molecules under clinical trials can be a good pool for repurposing through in-silico techniques to quickly identify promising drug candidates. The structural information of recently released crystal structures of main protease (M pro ) in APO and complex with inhibitors, N3, and 13b molecules was utilized to explore the binding site architecture through Molecular dynamics (MD) simulations. The stable state of M pro was used to conduct extensive virtual screening of the aforementioned drug pool. Considering the recent success of HIV protease molecules, we also used anti-protease molecules for drug repurposing purposes. The identified top hits were further evaluated through MD simulations followed by the binding free energy calculations using MM-GBSA. Interestingly, in our screening, several promising drugs stand out as potential inhibitors of M pro . However, based on control (N3 and 13b), we have identified six potential molecules, Leupeptin Hemisulphate, Pepstatin A, Nelfinavir, Birinapant, Lypression and Octreotide which have shown the reasonably significant MM-GBSA score. Further insight shows that the molecules form stable interactions with hot-spot residues, that are mainly conserved and can be targeted for structure-and pharmacophore-based designing. The pharmacokinetic annotations and therapeutic importance have suggested that these molecules possess drug-like properties and pave their way for in-vitro studies. ARTICLE HISTORY

Benzoquinones are class of natural quinones found chiefly in higher plants, fungi, bacteria and animal kingdom. They are involved in important biological functions such as bioenergetic transport, oxidative phosphorylation and electron transport processes. In recent years it has become increasingly clear that some of them possess potent antioxidant, anti-inflammatory and anticancer activities. There is clearly a common thread running through these activities and there have been a large number of studies carried out to unravel the mechanisms of these activities. In the present review we have provided a brief account of these studies especially covering these aspects. Although antioxidant potentials of these compounds constitute the basis of their biological activities its nature and scope is dictated by many microscopic biological environments. One of the important advantages offered by these compounds is the ease with which they can be synthesized and chemically manipulated. This can easily provide impetus for further research in developing some potentially useful drug molecules.

Purpose Pancreatic cancer (PC) is one of the deadliest of all tumors. Previously, we were the first to show that Thymoquinone (TQ) derived from black seed (Nigella sativa) oil has anti-tumor activity against PC. However, the concentration of TQ required was considered to be high to show this efficacy. Therefore, novel analogs of TQ with lower IC50 are highly desirable. Methods We have synthesized a series of 27 new analogs of TQ by modifications at the carbonyl sites or the benzenoid sites using single pot synthesis and tested their biological activity in PC cells. Results Among these compounds, TQ-2G, TQ-4A1 and TQ-5A1 (patent pending) were found to be more potent than TQ in terms of inhibition of cell growth, induction of apoptosis and modulation of transcription factor-NF-κB. We also found that our novel analogs were able to sensitize gemcitabine and oxaliplatin-induced apoptosis in MiaPaCa-2 (gemcitabine resistant) PC cells, which was associated with down-regulation of Bcl-2, Bcl-xL, survivin, XIAP, COX-2 and the associated Prostaglandin E2. Conclusion From our results, we conclude that three of our novel TQ analogs warrant further investigation against PC, especially in combination with conventional chemotherapeutic agents.

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Glycosyl triazoles are conveniently accessible and contain multiple metal-binding units that may assist in metal-mediated catalysis. Azide derivatives of d-glucose have been converted to their respective aryltriazoles and screened as ligands for the synthesis of 2-substituted benz-fused azoles and benzimidazoquinazolinones by Cu-catalyzed intramolecular Ullmann type C-heteroatom coupling. Good to excellent yields for a variety of benz-fused heterocyles were obtained for this readily accessible catalytic system.

Benzotriazole has been established as an efficient ligand in Cu-catalyzed cross-coupling of terminal alkynes to form 1,3-dialkynes using CuI as the catalyst and K 2 CO 3 as the base at room temperature in an open round-bottom flask. The established protocol has the following notable advantages: simple to handle, easy work-up, mild reaction condition, high substrate scope, requirement of less quantity of ligand and also Cu-catalyst, less expensive, and high reaction yield.

The plasticity in Ubiquitin Specific Proteases (USP7) inducing conformational changes at important areas has highlighted an intricate mechanism, by which USP7 is regulated. Given the importance of USP7 in oncogenic pathways and immune-oncology, identification of USP7 inhibitors has attracted considerable interest. Despite substantial efforts, the discovery of deubiquitinases (DUBs) inhibitors, knowledge of their binding site and understanding the possible mechanism of action has proven particularly challenging. We disclose the most likely binding site of P5091 (a potent USP7 inhibitor), which reveal a cryptic allosteric site through extensive computational studies in an inhibitor dependent and independent manner. Overall, these findings demonstrate the tractability and druggability of USP7. Through a series of molecular dynamics simulations and detailed quantitative analysis, a dynamically stable allosteric binding site near catalytic center of the inactive state of USP7 (site partially absent in active state), along with two newly identified sites have been revealed, which opens the avenue for rational structure-guided inhibitor designing in USP7 specific-manner.