What can we learn about the market reaction to macroeconomic surprise? Evidence from the COVID-19 crisis.

We investigate the impact of macroeconomic surprise and uncertainty on G7 financial markets around COVID-19 pandemic using two real-time, real-activity indexes recently constructed by Scotti (2016). We applies the wavelet analysis to detect the response of the stock markets to the macroeconomic surprise and an uncertainty indexes and then we use NARDL model to examine the asymmetric effect of the news surprise and uncertainty on the equity markets. We conduct our empirical analysis with the daily data from January, 2014 to September, 2020. Our findings indicate that G7 stock markets are sensitive to the macroeconomic surprise and uncertainty and the effect is more pronounced at the long term than the short term. Moreover, we show that the COVID-19 crisis supports the relationship between the macroeconomic indexes and the stock prices. The results are useful for investment decision-making for the investors on the G7 stock indices at different investment horizons.

Quinic and Digallic acids from Pistacia atlantica Desf. Leaves Extracts as Potent Dual Effect Inhibitors against main Protease and RNA-dependent RNA Polymerase of SARS-CoV-2.

BACKGROUND: Through this study, the Chemical composition realized by UHPLC-DADESI- MSn allowed the detection of different phenolic compound groups from Pistacia atlantica Desf. leaves extracts. We studied the inhibition of main protease (CL3 Mpro) and RNA-dependent RNA polymerase (RdRp) of the SARS-CoV-2 by the identified molecules through molecular docking. OBJECTIVE: The objective of this study is to identify compounds from Pistacia atlantica Desf. leaves extracts, which might have anti-viral effects. METHODS: Chemical composition was realized by UHPLC-DAD-ESI-MSn, and the inhibition of the main protease (CL3 Mpro) and RNA-dependent RNA polymerase (RdRp) of the SARS-CoV-2 was studied using molecular docking with Autodock Vina software. ADMET analysis was carried out. RESULTS: The identified compounds are quinic acid, digallic acid, galloylquinic acid, gallic acid, trigallic acid, digalloylquinic acids, trigalloylquinic acids and methyl gallate; digallic and quinic acids are the best inhibitors. Digallic acid had binding affinity energy (BAE) of -8.2 kcal/mol, and Ki of 1µM for the CL3 Mpro, Ki of 0.62 mM for the RdRp. Quinic acid showed Ki of 4.6 mM, recorded for both enzymes. Through ADMET analysis, we have found that the two molecules are good drug candidates. CONCLUSION: This is the first time that a group of identified compounds from Pistacia atlantica Desf. leaves are studied for their potential activity against the novel virus by inhibiting two key enzymes in its life cycle, and no further studies have been published in this context.

COVID-19 prophylaxis with doxycycline and zinc in health care workers: a prospective, randomized, double-blind clinical trial.

OBJECTIVES: This study aims to assess the efficacy of a combination treatment of doxycycline and zinc in the primary prevention of COVID-19 infection in Tunisian health care workers compared with two control groups. METHODS: We conducted a prospective, randomized, double-blind clinical trial over 5 months to determine the efficacy of a preventive combination treatment dose of doxycycline (100 mg/day) and zinc (15 mg/day), compared with a single-dose treatment with doxycycline versus placebo. The effectiveness of preventive treatment was measured by the significant decline in the number of cases of COVID-19 infection and/or a decrease in the viral load as determined by SARS-CoV-2 cycle threshold value using reverse transcription polymerase chain reaction tests. RESULTS: We detected a significant decrease of SARS-CoV-2 infection in the group that received both doxycycline and zinc compared with other participants. We also demonstrated that COVID-19 infection was neither associated with diabetes (P = 0.51) nor associated with hypertension (P = 0.99), asthma (P = 0.52), and chronic obstructive pulmonary disease (P = 0.27). CONCLUSION: Our findings indicated that preventive therapy reduced the risk of SARS-CoV-2. These results suggest that the combination of doxycycline and zinc has a protective effect in patients with SARS-CoV-2 infection.

In-silico investigation of phenolic compounds from leaves of Phillyrea Angustifolia L. as a potential inhibitor against the SARS-CoV-2 main protease (Mpro PDB ID:5R83) using a virtual screening method

There is currently a global COVID-19 pandemic caused by the severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) and its variants. This highly contagious viral disease continues to pose a major health threat global. The discovery of vaccinations is not enough to prevent their spread and dire consequences. To take advantage of the current drugs and isolated compounds, and immediately qualifying approach is required. The aim of our research is evaluation the potency for natural antiviral compounds against the SARS CoV-2 Mpro. Molecular docking of four phenolic compounds from Phillyrea Angustifolia leaves with SARS-CoV-2 Mpro has been conducted. Similarly, the stability of selected ligand-protein interactions has been determined using MD simulations. Moreover, the quantitative structure-activity relationship (QSAR), MMGBSA binding energies, pharmacokinetics, and drug-likeness predictions for selected phenolic have been reported. The selected phenolic compounds (Luteolin-7-O-glucoside, Apigenin-7-O-glucoside, Demethyl-oleuropein, and Oleuropein aglycone) revealed strong binding contacts in the two active pockets of a target protein of SARS-CoV-2 Mpro with the docking scores and highest binding energies with a binding energy of −8.2 kcal/mol;−7.8 kcal/mol;−7.2 kcal/mol and −7.0 kcal/mol respectively. Both Demethyloleoeuropein and Oleuropein aglycone can interact with residues His41 and Cys145 (catalytic dyad) and other amino acids of the binding pocket of Mpro. According to QSAR, studies on pharmacokinetics and drug-like properties suggested that oleuropein aglycone could be the best inhibitor of SARS-CoV-2 for new drug design and development. Further in vivo, in vitro, and clinical studies are highly needed to examine the potential of these phenolic compounds in the fight against COVID-19.

Exploring Structural Mechanism of COVID-19 Treatment with Glutathione as a Potential Peptide Inhibitor to the Main Protease: Molecular Dynamics Simulation and MM/PBSA Free Energy Calculations Study.

The 2019-novel coronavirus has unfolded everywhere in the world and obliged a billion human beings in open confinement, whereas many treatments, and vaccines have been proposed towards this pandemic. The main protease (Mpro) is an attractive drug target due to the fact that it is the essential protein for virus invasion. This research tests in silico the effect of five vitamins towards Mpro, by employing molecular docking (MD), molecular dynamics simulation (MDS) with molecular mechanics-Poisson-Boltzmann surface area (MM-PBSA) studies. To achieve this work, we have applied some software's as Autodock Vina, Discovery Studio Visualizer, APBS, and GROMACS. The inhibitors used were decided entirely on the basis of their importance in the production of red blood cells that prevent anemia, in lymphocyte immune system responses, in the regulation of reactive oxygen species production, such as tocopherol (vitamin E), thiamine (vitamin B1), pantothenic acid (vitamin B5), pyridoxine (vitamin B6), biotin (vitamin B7), and glutathione (GSH). The best inhibitor pose established at the highest repetition ratio (RR) and the minimal affinity energy value (MEV), then the best selected inhibitor was considered to MDS. The results indicate that GSH is the leading inhibitor model among the other tested vitamins in the active site of Mpro with a RR value of 94% and MEV of - 5.5 kcal/mol, its RMSD, RMSF, Rg, and hydrogen bonds show stability with Mpro. Furthermore, thiamine, biotin, and tocopherol are viewed as satisfying inhibitors to Mpro, but pyridoxine was observed as the weakest inhibitor. Based on our result, we could recommend the usage of glutathione and vitamin B family as a supportive strategy for feasible remedy of COVID-19 virus.

Oil price, US stock market and the US business conditions in the era of COVID-19 pandemic outbreak.

This paper contributes to Covid-19 outbreak impacts literature. We investigate the connectedness between stock market and oil prices under bullish and bearish economic conditions and uncertainty level at different investment horizons. We applied the wavelet framework on daily dataset cover the pre-COVID-19 and COVID-19 period. We find that the linkage between the economic and financial pairs is characterized by significant changes over the time during the sample period, where the huge co-movements has been identified during the pandemic period at the low scale. We show that due to lockdown policy and oil price shock, the stock return decline, the aggregate business conditions reached its lowest level and the uncertainty increase. The result indicates that the COVID-19 outbreak negatively affects the economy and the financial markets and support the sensitivity, especially between oil-stock, and economic condition and uncertainty.

Hispidin and Lepidine E: Two Natural Compounds and Folic Acid as Potential Inhibitors of 2019-novel Coronavirus Main Protease (2019- nCoVMpro), Molecular Docking and SAR Study.

BACKGROUND: 2019-nCoVis, a novel coronavirus was isolated and identified in 2019 in the city of Wuhan, China. On February 17, 2020 and according to the World Health Organization, 71, 429 confirmed cases worldwide were identified, among them 2162 new cases were recorded in the last 24 hours. One month later, the confirmed cases jumped to 179111, with 11525 new cases in the last 24 hours, with 7426 total deaths. No drug or vaccine is present at the moment for human and animal coronavirus. METHODS: The inhibition of 3CL hydrolase enzyme provides a promising therapeutic principle for developing treatments against CoViD-19. The 3CLpro (Mpro) is known for involving in counteracting the host innate immune response. RESULTS: This work presents the inhibitory effect of some natural compounds against 3CL hydrolase enzyme, and explains the main interactions in inhibitor-enzyme complex. Molecular docking study was carried out using Autodock Vina. By screening several molecules, we identified three candidate agents that inhibit the main protease of coronavirus. Hispidin, lepidine E, and folic acid are bound tightly in the enzyme, therefore strong hydrogen bonds have been formed (1.69-1.80Å) with the active site residues. CONCLUSION: This study provides a possible therapeutic strategy for CoViD-19.

Risk Spillover during the COVID-19 Global Pandemic and Portfolio Management

This paper aims to examine the volatility spillover, diversification benefits, and hedge ratios between U.S. stock markets and different financial variables and commodities during the pre-COVID-19 and COVID-19 crisis, using daily data and multivariate GARCH models. Our results indicate that the risk spillover has reached the highest level during the COVID-19 period, compared to the pre-COVID period, which means that the COVID-19 pandemic enforced the risk spillover between U.S. stock markets and the remains assets. We confirm the economic benefit of diversification in both tranquil and crisis periods (e.g., a negative dynamic conditional correlation between the VIX and SP500). Moreover, the hedging analysis exhibits that the Dow Jones Islamic has the highest hedging effectiveness either before or during the recent COVID19 crisis, offering better resistance to uncertainty caused by unpredictable turmoil such as the COVID19 outbreak. Our finding may have some implications for portfolio managers and investors to reduce their exposure to the risk in their portfolio construction.

Effects of the COVID-19 pandemic on the US stock market and uncertainty: A comparative assessment between the first and second waves.

This paper makes the first comparative assessment of the impacts of the first and second waves of the ongoing COVID-19 pandemic for the US stock market and its uncertainty. To this end, we investigate the dynamic conditional correlation and the asymmetric impacts of shocks on the correlation between the US and Chinese stock markets before and during the COVID-19 crisis. Furthermore, we analyze and compare the relationship between the COVID-19 pandemic and US returns and uncertainty during the first and second waves of the pandemic. First, we find that the dynamic correlation approach supports the presence of volatility spillovers (contagion effects) between the two stock markets, especially during the rapid spread phase of COVID-19 in the US. Second, the analysis of news impact correlation surfaces shows that the shocks to the US and Chinese markets have asymmetric effects on the correlation between the two markets. Finally, we find a persistent link between US returns, uncertainty, and the COVID-19 pandemic during the first and second waves of the outbreak. Our results prove that the pandemic has shown harmful consequences for financial markets in general and the US economy in particular.