Poly(ethylene glycol) (PEG) is the most widely used polymer in delivering anticancer drugs clinically. PEGylation (i.e., the covalent attachment of PEG) of peptides proteins, drugs, and bioactives is known to enhance the aqueous solubility of hydrophobic drugs, prolong circulation time, minimize nonspecific uptake, and achieve specific tumor targetability through the enhanced permeability and retention effect. Numerous PEG-based therapeutics have been developed, and several have received market approval. A vast amount of clinical experience has been gained which has helped to design PEG prodrug conjugates with improved therapeutic efficacy and reduced systemic toxicity. However, more efforts in designing PEG-based prodrug conjugates are anticipated. In light of this, the current paper highlights the synthetic advances in PEG prodrug conjugation methodologies with varied bioactive components of clinical relevance. In addition, this paper discusses FDA-approved PEGylated delivery systems, their intended clinical applications, and formulations under clinical trials.

Aim: In view of the strong immunomodulatory and antiviral activity of andrographolide and its derivative, the present study aimed to investigate the binding a nities of andrographolide and its derivative 14deoxy-11,12-didehydroandrographolide with 3 major targets of COVID-19 i.e. 3CLpro, PLpro and spike protein followed by their gene-set enrichment analysis with special reference to immune modulation. Materials and methods: SMILES of the compounds were retrieved from DigepPred database and the proteins identi ed were queried in STRING to evaluate the protein-protein interaction and modulated pathways were identi ed concerning the KEGG database. Drug-likeness and ADMET pro les were evaluated using MolSoft and admet SAR 2.0, respectively. Molecular docking was carried using autodock 4.0. Results: Andrographolide and 14-Deoxy-11,12-didehydroandrographolide were predicted to have a high binding a nity with papain-like protease i.e.-6.7 kcal/mol and-6.5 kcal/mol, respectively while they interact with equal binding energies with 3clpro (-6.8 kcal/mol) and spike protein (-6.9 kcal/mol). Network pharmacology analysis revealed that both compounds modulated the immune system through the regulation of chemokine signaling pathway, Rap1 signaling pathway, Cytokine-cytokine receptor interaction, MAPK signaling pathway, NF-kappa B signaling pathway, Rassignaling pathway, p53 signaling pathway, HIF-1 signaling pathway, and Natural killer cell-mediated cytotoxicity. Although the 14deoxy-11,12-didehydroandrographolide scored higher drug-likeness character, it showed less potency to interaction with targeted proteins of COVID-19. Conclusion: The study suggests the strong interaction of the andrographolide and its derivative 14-deoxy-11,12-didehydroandrographolide against target proteins associated with COVID-19. Further, network pharmacology analysis elucidated the different pathways of immunomodulation. However, clinical research should be conducted to con rm the current ndings.

COVID-19 has ravaged the world and is the greatest of pandemics in modern human history, in the absence of treatment or vaccine, the mortality and morbidity rates are very high. The present investigation identifies potential leads from the plant Withania somnifera (Indian ginseng), a well-known antiviral, immunomodulatory, anti-inflammatory and a potent antioxidant plant, using molecular docking and dynamics studies. Two different protein targets of SARS-CoV-2 namely NSP15 endoribonuclease and receptor binding domain of prefusion spike protein from SARS-CoV-2 were targeted. Molecular docking studies suggested Withanoside X and Quercetin glucoside from W. somnifera have favorable interactions at the binding site of selected proteins, that is, 6W01 and 6M0J. The top-ranked phytochemicals from docking studies, subjected to 100 ns molecular dynamics (MD) suggested Withanoside X with the highest binding free energy (DG bind ¼ À89.42 kcal/mol) as the most promising inhibitor. During MD studies, the molecule optimizes its conformation for better fitting with the receptor active site justifying the high binding affinity. Based on proven therapeutic, that is, immunomodulatory, antioxidant and anti-inflammatory roles and plausible potential against n-CoV-2 proteins, Indian ginseng could be one of the alternatives as an antiviral agent in the treatment of COVID 19. HIGHLIGHTSWithania somnifera has antiviral potential. Phytochemicals of Ashwagandha showed promising in silico docking and molecular dynamics results.

COVID-19 has ravaged the world and is the greatest of pandemics in human history, in the absence of treatment or vaccine the mortality and morbidity rates are very high. The present investigation was undertaken to screen and identify the potent leads from the Indian Ayurvedic herb, Asparagus racemosus (Willd.) against SARS-CoV-2 using molecular docking and dynamics studies. The docking analysis was performed on the Glide module of Schr€ odinger suite on two different proteins from SARS-CoV-2 viz. NSP15 Endoribonuclease and spike receptor-binding domain. Asparoside-C, Asparoside-D and Asparoside -F were found to be most effective against both the proteins as confirmed through their docking score and affinity. Further, the 100 ns molecular dynamics study also confirmed the potential of these compounds from reasonably lower root mean square deviations and better stabilization of Asparoside-C and Asparoside-F in spike receptor-binding domain and NSP15 Endoribonuclease respectively. MM-GBSA based binding free energy calculations also suggest the most favourable binding affinities of Asparoside-C and Asparoside-F with binding energies of À62.61 and À55.19 Kcal/mol respectively with spike receptor-binding domain and NSP15 Endoribonuclease. HIGHLIGHTSAsparagus racemosus have antiviral potential Phytochemicals of Shatavari showed promising in-silico docking and MD results Asparaoside-C and Asparoside-F has good binding with target proteins Asparagus racemosus holds promise as SARS-COV-2 (S) and (N) proteins inhibitor

Bioflavonoids are the largest group of plant-derived polyphenolic compounds with diverse biological potential and have also been proven efficacious in the treatment of Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS). The present investigation validates molecular docking, simulation, and MM-PBSA studies of fifteen bioactive bioflavonoids derived from plants as a plausible potential antiviral in the treatment of COVID-19. Molecular docking studies for 15 flavonoids on the three SARS CoV-2 proteins, non-structural protein-15 Endoribonuclease (NSP15), the receptor-binding domain of spike protein (RBD of S protein), and main protease (M pro /3CL pro ) were performed and selected protein-ligand complexes were subjected to Molecular Dynamics simulations. The molecular dynamics trajectories were subjected to free energy calculation by the MM-PBSA method. All flavonoids were further assessed for their effectiveness as adjuvant therapy by network pharmacology analysis on the target proteins. The network pharmacology analysis suggests the involvement of selected bioflavonoids in the modulation of multiple signaling pathways like p53, FoxO, MAPK, Wnt, Rap1, TNF, adipocytokine, and leukocyte transendothelial migration which plays a significant role in immunomodulation, minimizing the oxidative stress and inflammation. Molecular docking and molecular dynamics simulation studies illustrated the potential of glycyrrhizic acid, amentoflavone, and mulberroside in inhibiting key SARS-CoV-2 proteins and these results could be exploited further in designing future ligands from natural sources.