Mushroom-derived bioactive compounds potentially serve as the inhibitors of SARS-CoV-2 main protease: An in silico approach

Background and aim Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has now become the world pandemic. There is a race to develop suitable drugs and vaccines for the disease. The anti-HIV protease drugs are currently repurposed for the potential treatment of COVID-19. The drugs were primarily screened against the SARS-CoV-2 main protease. With an urgent need for safe and effective drugs to treat the virus, we have explored natural products isolated from edible and medicinal mushrooms that have been reported to possess anti-HIV protease. Experimental procedures We have examined 36 compounds for their potential to be SARS-CoV-2 main protease inhibitors using molecular docking study. Moreover, drug-likeness properties including absorption, distribution, metabolism, excretion and toxicity were evaluated by in silico ADMET analysis. Results Our AutoDock study showed that 25 of 36 candidate compounds have the potential to inhibit the main viral protease based on their binding affinity against the enzyme’s active site when compared to the standard drugs. Interestingly, ADMET analysis and toxicity prediction revealed that 6 out of 25 compounds are the best drug-like property candidates, including colossolactone VIII, colossolactone E, colossolactone G, ergosterol, heliantriol F and velutin. Conclusion Our study highlights the potential of existing mushroom-derived natural compounds for further investigation and possibly can be used to fight against SARS-CoV-2 infection. Taxonomy (classification by evise) Disease, Infectious Disease, Respiratory System Disease, Covid-19, Traditional Medicine, Traditional Herbal Medicine, Phamaceutical Analysis

In Vitro Anti-HIV-1 Reverse Transcriptase and Integrase Properties of Punica granatum L. Leaves, Bark, and Peel Extracts and Their Main Compounds.

In a search for natural compounds with anti-HIV-1 activity, we studied the effect of the ethanolic extract obtained from leaves, bark, and peels of Punica granatum L. for the inhibition of the HIV-1 reverse transcriptase (RT)-associated ribonuclease H (RNase H) and integrase (IN) LEDGFdependent activities. The chemical analyses led to the detection of compounds belonging mainly to the phenolic and flavonoid chemical classes. Ellagic acid, flavones, and triterpenoid molecules were identified in leaves. The bark and peels were characterized by the presence of hydrolyzable tannins, such as punicalins and punicalagins, together with ellagic acid. Among the isolated compounds, the hydrolyzable tannins and ellagic acid showed a very high inhibition (IC50 values ranging from 0.12 to 1.4 microM and 0.065 to 0.09 microM of the RNase H and IN activities, respectively). Of the flavonoids, luteolin and apigenin were found to be able to inhibit RNase H and IN functions (IC50 values in the 3.7–22 microM range), whereas luteolin 7-O-glucoside showed selective activity for HIV-1 IN. In contrast, betulinic acid, ursolic acid, and oleanolic acid were selective for the HIV-1 RNase H activity. Our results strongly support the potential of non-edible P. granatum organs as a valuable source of anti-HIV-1 compounds

Chelation motifs affecting metal-dependent viral enzymes: N′-acylhydrazone ligands as dual target inhibitors of HIV-1 Integrase and Reverse Transcriptase Ribonuclease H domain

Human immunodeficiency virus type 1 (HIV-1) infection, still represent a serious global health emergency. The chronic toxicity derived from the current anti-retroviral therapy limits the prolonged use of several antiretroviral agents, continuously requiring the discovery of new antiviral agents with innovative strategies of action. In particular, the development of single molecules targeting two proteins (dual inhibitors) is one of the current main goals in drug discovery. In this contest, metal-chelating molecules have been extensively explored as potential inhibitors of viral metal-dependent enzymes, resulting in some important classes of antiviral agents. Inhibition of HIV Integrase (IN) is, in this sense, paradigmatic. HIV-1 IN and Reverse Transcriptase-associated Ribonuclease H (RNase H) active sites show structural homologies, with the presence of two Mg(II) cofactors, hence it seems possible to inhibit both enzymes by means of chelating ligands with analogous structural features. Here we present a series of N′-acylhydrazone ligands with groups able to chelate the Mg(II) hard Lewis acid ions in the active sites of both the enzymes, resulting in dual inhibitors with micromolar and even nanomolar activities. The most interesting identified N′-acylhydrazone analog, compound 18, shows dual RNase H-IN inhibition and it is also able to inhibit viral replication in cell-based antiviral assays in the low micromolar range. Computational modeling studies were also conducted to explore the binding attitudes of some model ligands within the active site of both the enzymes

Molecular docking: Bioactive compounds of Mimosa pudica as an inhibitor of Candida albicans Sap 3

Candida albicans (C. albicans) is a commensal microbiota that resides in humans. However, in certain cases, C. albicans can infect and cause several diseases to humans. This study aimed to investigate the interaction between Mimosa pudica bioactive compounds and C. albicans Sap 3. Molecular docking analysis was carried out using YASARA structure. The procedures involved preparation of ligands and target receptor, molecular docking, data analysis and visualization. All 3D ligands were downloaded from PubChem NCBI, while target receptor was downloaded from RCSB PDB. The interaction between Mimosa pudica bioactive compounds against Sap 3 resulted in a binding energies ranges from 5,168 – 7,480 kcal/mol and most of the interactions formed were relatively strong. Furthermore, the test ligands had contact with the catalytic residues and substrate binding site pockets S1/S2/S3/S4 on the target receptor. Bioactive compounds of Mimosa pudica have relatively good interactions in inhibiting C. albicans Sap

<i>Garcinia cambogia</i> phenolics as potent anti-COVID-19 agents:phytochemical profiling, biological activities, and molecular docking

COVID-19 is a disease caused by the coronavirus SARS-CoV-2 and became a pandemic in a critically short time. Phenolic secondary metabolites attracted much attention from the pharmaceutical industries for their easily accessible natural sources and proven antiviral activity. In our mission, a metabolomics study of the Garcinia cambogia Roxb. fruit rind was performed using LC-HRESIMS to investigate its chemical profile, especially the polar aspects, followed by a detailed phytochemical analysis, which led to the isolation of eight known compounds. Using spectrometric techniques, the isolated compounds were identified as quercetin, amentoflavone, vitexin, rutin, naringin, catechin, p-coumaric, and gallic acids. The antiviral activities of the isolated compounds were investigated using two assays; the 3CL-Mpro enzyme showed that naringin had a potent effect with IC50 16.62 &mu;g/mL, followed by catechin and gallic acid (IC50 26.2, 30.35 &mu;g/mL, respectively), while the direct antiviral inhibition effect of naringin confirmed the potency with an EC50 of 0.0169 &mu;M. To show the molecular interaction, in situ molecular docking was carried out using a COVID-19 protease enzyme. Both biological effects and docking studies showed the hydrophobic interactions with Gln 189 or Glu 166, per the predicated binding pose of the isolated naringin

Natural Phenolic Acids and Their Derivatives against Human Viral Infections

Natural compounds with structural diversity and complexity offer a great chance to find new antiviral agents. Phenolic acids have attracted considerable attention due to their potent antiviral abilities and unique mechanisms. The aim of this review is to report new discoveries and update pertaining to antiviral phenolic acids. The antiviral phenolic acids were classified according to their structural properties and antiviral types. Meanwhile, the antiviral characteristics and structure-activity relationships of phenolic acids and their derivatives were summarized. Natural phenolic acids and their derivatives possess potent inhibitory effects on multiple viruses in humans such as human immunodeficiency virus, hepatitis C virus, hepatitis B virus, herpes simplex virus, influenza virus and respiratory syncytial virus etc. In particular, caffeic acid/gallic acid and their derivatives exhibit outstanding antiviral properties through a variety of modes of action. In conclusion, naturally derived phenolic acids especially caffeic acid/gallic acid and their derivatives may be regarded as novel promising antiviral leads or candidates. Additionally, scarcely any of these compounds have been used as antiviral treatments in clinical practice. Therefore, these phenolic acids with diverse skeletons and mechanisms provide us an excellent resource for finding novel antiviral drugs

Inhibitory Potential of Chromene Derivatives on Structural and Non-Structural Proteins of Dengue Virus

Dengue fever is a mosquito-borne viral disease that has become a serious health issue across the globe. It is caused by a virus of the Flaviviridae family, and it comprises five different serotypes (DENV-1 to DENV-5). As there is no specific medicine or effective vaccine for controlling dengue fever, there is an urgent need to develop potential inhibitors against it. Traditionally, various natural products have been used to manage dengue fever and its co-morbid conditions. A detailed analysis of these plants revealed the presence of various chromene derivatives as the major phytochemicals. Inspired by these observations, authors have critically analyzed the anti-dengue virus potential of various 4H chromene derivatives. Further, in silico, in vitro, and in vivo reports of these scaffolds against the dengue virus are detailed in the present manuscript. These analogues exerted their activity by interfering with various stages of viral entry, assembly, and replications. Moreover, these analogues mainly target envelope protein, NS2B-NS3 protease, and NS5 RNA-dependent RNA polymerase, etc. Overall, chromene-containing analogues exerted a potent activity against the dengue virus and the present review will be helpful for the further exploration of these scaffolds for the development of novel antiviral drug candidates

POTENTIAL PHYTOCONSTITUENTS FROM NATURAL PRODUCTS FOR COMBATING AGAINST CORONAVIRUS DISEASE-19 (SEVERE ACUTE RESPIRATORY SYNDROME CORONAVIRUS‐2) - A REVIEW

Coronavirus called as coronavirus diseases (COVID)-19 (severe acute respiratory syndrome coronavirus [SARS‐CoV]‐2) is a viral infection which is spreading to a great extent and affecting many people worldwide, many developed and developing countries are severely affected by the virus. The World Health Organization (WHO) is taking serious preventive measures to stop this viral infection worldwide. The coronavirus is a big threat to human beings and controlling the emerging viral infections is a global concern. Antiviral drug such as Remdesivir has been approved by the FDA, but combating against these viral infections is a great challenge to scientists and researchers with the available few antiviral drugs due to severe side effects and toxicity. Many drugs such as hydroxy chloroquin, Remdesivir, and vaccines have been recommended for combating this virus. Few Polyherbal formulations and Ayurvedic formulations containing antiviral phytoconstituents have been recommended to boost the immunity. Some drugs and phytoconstituents are under different phases of human clinical trials. The currently available synthetic drugs and vaccines for the treatment of viral infections have severe side effects. Medicinal plants play a critical role in treating viral infections by developing immunity against viral diseases. Some medicinal plants which were used as antipyretic, analgesic, and anti-inflammatory activity helped in treating various diseases and viral infections. Many plants contain flavonoids such as quercetin, luteolin, apigenin, and polyphenols such as thymoquinone, phytosteroids such as cucurbitacin and others which may likely to act as antioxidants and immunomodulatory that can fight against COVID-19. The current review provides information on phytochemical constituents present in medicinal plants, their mechanism of action, in silico molecular docking studies and human clinical trials to treat viral disorders

Tailored functionalization of natural phenols to improve biological activity

Phenols are widespread in nature, being the major components of several plants and essential oils. Natural phenols' anti-microbial, anti-bacterial, anti-oxidant, pharmacological and nutritional properties are, nowadays, well established. Hence, given their peculiar biological role, numerous studies are currently ongoing to overcome their limitations, as well as to enhance their activity. In this review, the functionalization of selected natural phenols is critically examined, mainly highlighting their improved bioactivity after the proper chemical transformations. In particular, functionalization of the most abundant naturally occurring monophenols, diphenols, lipidic phenols, phenolic acids, polyphenols and curcumin derivatives is explored