Molecular dynamics and absolute binding free energy studies of piperine derivatives as potential inhibitors of SARS-CoV-2 main protease

Piperine: Chemistry and Biology

Piperine is a plant-derived promising piperamide candidate isolated from the black pepper (Piper nigrum L.). In the last few years, this natural botanical product and its derivatives have aroused much attention for their comprehensive biological activities, including not only medical but also agricultural bioactivities. In order to achieve sustainable development and improve survival conditions, looking for environmentally friendly pesticides with low toxicity and residue is an extremely urgent challenge. Fortunately, plant-derived pesticides are rising like a shining star, guiding us in the direction of development in pesticidal research. In the present review, the recent progress in the biological activities, mechanisms of action, and structural modifications of piperine and its derivatives from 2020 to 2023 are summarized. The structure-activity relationships were analyzed in order to pave the way for future development and utilization of piperine and its derivatives as potent drugs and pesticides for improving the local economic development.

Unraveling bioactive metabolites of mangroves as putative inhibitors of SARS-CoV-2 Mpro and RBD proteins: molecular dynamics and ADMET analysis

COVID-19 is a deadly pandemic caused by Corona virus leading to millions of deaths worldwide. Till today no medicine was available to cure this disease. This study selected 262 potential bioactive natural products derived from mangroves to inhibit the main protease (Mpro) and receptor-binding domain (RBD) protein of the COVID-19 virus. All the ligands were subjected to Adsorption Digestion Metabolism Excretion and Toxicity (ADMET) predictions and docking studies using AutodockVina. Among all the ligands, NP_143 (Shearinine A) and NP_242 (Amentoflavone), having the highest docking score of 10.2 and 10.1 Kj/mole, respectively, were picked for 100 ns of Molecular Dynamics using GROMACS. The trajectories generated were used to estimate Root mean square deviation (RMSD), Root mean square fluctuations (RMSF), Radius of Gyrations (RG), Solvent accessible surface area (SASA), and Hydrogen bonds. From the data generated, both the ligands have good binding ability at the active site of Mpro protein and do not deviate much. They have strong interactions with the amino acids during the 100 ns of simulations and can thus be considered potential drug candidates.Communicated by Ramaswamy H. Sarma.

Neuroprotective Agents with Therapeutic Potential for COVID-19

COVID-19 patients can exhibit a wide range of clinical manifestations affecting various organs and systems. Neurological symptoms have been reported in COVID-19 patients, both during the acute phase of the illness and in cases of long-term COVID. Moderate symptoms include ageusia, anosmia, altered mental status, and cognitive impairment, and in more severe cases can manifest as ischemic cerebrovascular disease and encephalitis. In this narrative review, we delve into the reported neurological symptoms associated with COVID-19, as well as the underlying mechanisms contributing to them. These mechanisms include direct damage to neurons, inflammation, oxidative stress, and protein misfolding. We further investigate the potential of small molecules from natural products to offer neuroprotection in models of neurodegenerative diseases. Through our analysis, we discovered that flavonoids, alkaloids, terpenoids, and other natural compounds exhibit neuroprotective effects by modulating signaling pathways known to be impacted by COVID-19. Some of these compounds also directly target SARS-CoV-2 viral replication. Therefore, molecules of natural origin show promise as potential agents to prevent or mitigate nervous system damage in COVID-19 patients. Further research and the evaluation of different stages of the disease are warranted to explore their potential benefits.