Molecular structure, optoelectronic properties, spectroscopic (FT-IR, FT-Raman and UV–Vis), H-BDE, NBO and drug likeness investigations on 7, 8-benzocoumarin-4-acetic acid (7BAA)

Unequal Behaviour between Hydrolysable Functions of Nirmatrelvir under Stress Conditions: Structural and Theoretical Approaches in Support of Preformulation Studies

Nirmatrelvir is an antiviral drug approved for the treatment of COVID-19. The available dosage form consists of tablets marketed under the brand name PAXLOVID^®. Although knowledge of nirmatrelvir’s intrinsic stability may be useful for any potential development of other pharmaceutical forms, no data regarding this matter is available to date. Preliminary forced degradation studies have shown that the molecule is stable under oxidative and photolytic conditions, while hydrolytic conditions, both acidic and basic, have proven deleterious. Indeed, the molecule presents a priori several functions that can undergo hydrolysis, i.e., three amide moieties and a nitrile function. However, considering the degradation products formed under forced conditions and which were detected and identified by LC-UV-HRMSⁿ, the hydrolysis process leading to their formation is selective since it involved only 2 of the 4 hydrolysable functions of the molecule. Ab initio studies based on density functional theory (DFT) have helped better understand these reactivity differences in aqueous media. Some hydrolyzable functions of nirmatrelvir differ from others in terms of electrostatic potential and Fukui functions, and this seems to correlate with the forced degradation outcomes.

Synthesis, spectroscopic (FT-IR, FT-Raman, NMR & UV-Vis), reactive (ELF, LOL, Fukui), drug likeness and molecular docking insights on novel 4-[3-(3-methoxy-phenyl)-3-oxo-propenyl]-benzonitrile by experimental and computational methods

The spectroscopic analysis such as FT-IR, FT-Raman, UV-Vis and NMR are conducted for the synthesized molecule by both experimental and theoretical approach. The theoretical computations were achieved by DFT method with B3LYP functional and 6-311 ++ G (d, P) basis set. Firstly the geometrical parameters obtained by DFT are compared with the related experimental parameters. Experimental FT-IR and FT-Raman spectra of the title molecule have been acquired. The vibrational analysis is conducted and the assignments concerned to the observed bands are mentioned through the potential energy distribution (PED). The GIAO method was employed for theoretical NMR analysis and the results are compared with experimental chemical shifts. In accumulation to these analyses NLO, NBO, FMO and MEP analysis have been conducted to understand the nature of the molecule. ELF and LOL were performed. The drug likeness and molecular docking studies also conducted. The potency of inhibition of molecule against MPRO and PLPRO receptors has been performed using molecular docking studies.

Synthesis, Structural Characterizations, and Quantum Chemical Investigations on 1-(3-Methoxy-phenyl)-3-naphthalen-1-yl-propenone

In the present study, 1-(3-methoxy-phenyl)-3-naphthalen-1-yl-propenone (MPNP) is synthesized and characterized by several experimental techniques such as Fourier transform-infrared spectroscopy (FT-IR), FT-Raman, NMR and UV-vis spectral methods. The similar techniques are also investigated by the computational method using Gaussian software. The density functional theory (DFT) method is used to obtain the optimized structure using the B3LYP/6-311++G(d,p) basis set. This optimization procedure of the molecule gives the minimum energy confirmation of the structure. The computed geometrical parameters are compared with experimental data. The experimental FT-IR and FT-Raman spectra of MPNP are obtained in the regions 4000-400 and 4000-50 cm-1 respectively. The detailed vibrational assignments of the molecule are obtained with the support of potential energy distribution. The theoretical NMR (1H and 13C) analysis is conducted by the GIAO method for its structural characterization and compared with experimental chemical shifts. The experimental UV-vis spectrum is obtained in the dimethyl sulfoxide solvent and compared with the theoretically computed spectrum by the time-dependent DFT method. In addition to these studies, other analyses such as nonlinear optical, natural bonds orbital, frontier molecular orbital, molecular electrostatic potential, and NCI have been conducted to understand the nature of the molecule. The title molecule is docked and also the drug-likeness, ADMET studies were carried out. The RBD domain bound to the ACE2 receptor during the fusion makes spike glycoprotein an elusive therapeutic target in SARS-CoV-2 infection.

Quantum chemical calculation, performance of selective antimicrobial activity using molecular docking analysis, RDG and experimental (FT-IR, FT-Raman) investigation of 4-[{2-[3-(4-chlorophenyl)-5-(4-propan-2-yl) phenyl)-4, 5-dihydro- 1H- pyrazol-1-yl]-4-oxo-1, 3- thiazol-5(4H)-ylidene} methyl] benzonitrile

The research received a great deal of worldwide attention due to the nature of interpretation before the experimental process. Based on the systematic process the structure of thiazole -pyrazole compound 4-[{2-[3-(4-chlorophenyl)-5-(4-propan-2-yl) phenyl)-4, 5-dihydro- 1H- pyrazol-1-yl]-4-oxo-1, 3- thiazol-5(4H)-ylidene} methyl] benzonitrile [CPTBN] was investigated. In the first level, the spectral statistics on experimental FT-IR and FT- Raman was reported. At the next level, geometrical parameters was theoretically acquired from density functional theory (DFT) using B3LPY/6-31G and 6-311G basis set. The computed Wavenumber were collected and compared with the experimental data. The vibrational modes were interpreted in terms of potential energy distribution (PED) results. The FMO, MEP, and NBO analysis further validated the electrophilic and nucleophilic interaction in the molecular systems. Two grams-positive bacteria: staphylococcus aureus, Bacillus subtilis and two gram-negative bacteria: Esherichia coli, Pseudomonas aeruginosa was performed for antibacterial activity. Two fungal strain Candida albicans and Aspergillus Niger was carried out against a ligand using anti-fungal activity. The molecular docking analysis explores the antimicrobial and selective potential inhibitory nature of the binding molecule. Besides, RDG and ELF analysis were also performed to show the nature of interactions between the molecule.

Intrinsic stability of the antiviral drug umifenovir by stress testing and DFT studies

Umifenovir is an antiviral drug approved in China and Russia for the treatment of influenza. The available dosage form consists of capsules marketed under the brand name Arbidol®. Due to its broad spectrum, umifenovir may also be used in other viral contexts, alone or combined with other antiviral drugs. Although knowledge of umifenovir intrinsic stability may be useful for any potential development of other pharmaceutical forms for other routes of administration and for quality risk management, no data regarding this matter is available to date. In this study, the exploration of the molecule's behaviour under hydrolytic, oxidative and photolytic conditions was carried out experimentally and supported by density functional theory (DFT) studies. It comes out that umifenovir is sensitive to these stress conditions giving rise to 6 structurally characterized degradation products. The one-electron oxidation process produced on the sulphur atom is probably the main cause of umifenovir degradation with reference to the structures of the degradation products formed and the DFT data.

Synthesis, antimicrobial activities, docking studies and computational calculations of new bis-1,4-phenylene -1H-1,2,3-triazole derivatives utilized ultrasonic energy

In this elucidation, we studied the utility of condensation reaction between 1,4-phenylenediamine (1) with acetyl acetone (2) with hydrazine hydrate utilized ultrasonic energy in one step reaction to afford the corresponding 1,1'-(1,4-phenylenebis (5-methyl-1H-1,2,3-triazole-1,4-diyl))bis(ethan-1-one) (4) in excellent yield. The ethanol solution of bis triazole (4) and different aldehyde derivatives were sonicated at 75 °C for 2 h to afford chalcone derivatives 5a-d which were confirmed via spectral data such as FTIR, ¹HNMR, ¹³CNMR and mass spectra. Moreover, the intermolecular cyclization of chalcone (5a) with NH₂NH₂ in sodium hydroxide solution to give the corresponding 4,5-dihydro-1H-pyrazol-5-yl)-1H-indole (6) using ultrasonic energy for 4 h, while the Michael addition of chalcones (5a) and (5 b) with thiourea in basic condition to afford the corresponding pyrimidine-2-thiol derivatives (7) and (9). Treatment of compound (7) with NH₂NH₂ to afford 1,4-bis(4-(2-hydrazineyl-6-(1H-indol-3-yl)pyrimidin-4-yl) derivatives (8). The synthesized compounds were screened against various microbial strains and displayed excellent antimicrobial potential. Additionally, the docking studies of these nine compounds were carried out with (PDB ID:3t88), (PDB ID:2wje), (PDB ID:4ynt) and (PDB ID:1tgh) which were attached with different amino acids with shortage bond length, and it was noticed that PMTS₁, PMTS₂ and PMTS₃ were the most stable compounds with the lowest energy affinity which is compatible with biological study. Furthermore, the theoretical investigation of bis-triazole compounds were optimized via DFT/B3LYP/6-31G(d) level which showed the hyperconjugation of nitrogen atoms and elucidated their physical parameters and NBO charges and confirmed their stability and biological activity.Communicated by Ramaswamy H. Sarma.