Novichoks are the suspected nerve agents in the March 2018 Skripal poisoning. In this context, the novichok agent A234 (chemical structure proposed by Mirzayanov) was studied using computational methods to shed light on its molecular, electronic, spectroscopic, thermodynamic and toxicity parameters as well as on potential thermal and hydrolysis degradation pathways. The poisoning action and antidote of A234 were also investigated. Some of these parameters were compared to three common G- and V-series nerve agents, namely GB, VR and VX. The research findings should be useful towards the detection, development of antidotes and destruction of A234.

The current research used a virtual screening method to study 57 isolated phytochemicals (alkaloids, phytosterols, and flavonoids) against the SARS-CoV-2 main protease (M^pro). The absorption, distribution, metabolism, excretion, and toxicity (ADMET) of the selected compounds were analysed using admetSAR tool while SwissADME and Molinspiration chemoinformatics tools were used to examine the oral bioavailability and drug-likeness properties. Parameters such as physicochemical properties, activity spectra for substances (PASS) prediction, bioactivity, binding mode, and molecular interactions were also analysed. Our results favoured Lupeol (–8.6 kcal/mol), Lupenone (–7.7 kcal/mol), Hesperetin (–7.4 kcal/mol), Apigenin (–7.3 kcal/mol) and Castasterone (–7.3 kcal/mol) as probable inhibitors of SARS-CoV-2. This is because of their good binding affinities, bioactivities, drug-likeness, ADMET properties, PASS properties, oral bioavailability, binding mode and their interactions with the active site of the target receptor compared to Remdesivir and Azithromycin. Therefore, these compounds could be explored towards the development of new therapeutic agents against SARS-CoV-2. Graphical Abstract

The purpose of this study was to remove dyes from synthetic dyed wastewater using activated carbon derived from rice husk. The initial dye concentration was 45 mg/L. The batch adsorption worked best in an acidic medium of pH 2, adsorbent dosage of 13 g/L and agitation speed of 100 rpm with maximum dye removal of 80% after 10 min. The maximum adsorption capacity of the absorbent was found to be 2.0 mg/g with a final dye concentration of 10.8 mg/L. The adsorption was found to be a non-spontaneous, endothermic chemisorption process with less disorder which best fitted the Temkin model and followed pseudo-second order. For column adsorption, the highest q_o corresponds to 12.8 mg/g and the maximum dye removal was above 99.5%. Some of the experimental deductions were confirmed by gas-phase computations [B3LYP/6-31G(d)].

A theoretical study of the hydrolysis mechanism of A-234 [EtO–P(O)(F)–NC(Me)–N(Et)₂]; the suspected novichok agent in the Skripal attack.

Fullerenes have received attentions due to their versatile properties. Molecular structures and electronic properties namely binding energy, band gap, electrophilicity index and molecular topological analysis were studied for undoped and silicon doped C ₂₀ fullerenes and favipiravir in order to search for possible application of the systems as drug delivery vehicles. Density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM) were used for the research. Molecular structures having the interaction edges of SiC ₁₉ … OH in water and SiC ₁₉ …C=O in gas phase were found as those most stable with binding energies of -57.28 kcal/mol and -43.46 kcal/mol correspondingly. The results and parameters found in this research may provide additional insights into drug delivery systems.