Current Physical Chemistry - Volume 13, Issue 1, 2023

Biologically active compounds play a very important role in our daily life. Almost all biologically active compounds contain heteroatoms and among these, a major portion is heterocycles. Heterocycles are a significant component in drug development programs. Drugs containing a heterocyclic moiety are highly valued resources in the fight against human and animal diseases. Some of these compounds are utilized as anticonvulsants antivirals, anti-inflammatory, and central vasodilators, while others are used as nontherapeutic anthelmintics, diuretics, anti-hypertensives, uricosurics, fungicides, bactericides, and herbicides. In this review, we have discussed the chemistry of heterocyclic compounds such as Quinoxaline, Triazole, Pyrimidine, Pyridine, Oxadiazole, Thiazole, Indole, and Azepine. Besides some of their recent synthetic methodologies, their pharmaceutical importance is also discussed. Undoubtedly, the contents of this review will motivate readers to do more novel work in this area which will accelerate the journey toward the exploration of the pharmacological activity of heterocyclic compounds.

Background: Copper is a metal that is widely used in many fields such as industry and construction, etc. These different industrial sectors use acid solutions such as nitric acid and hydrochloric acid, etc. The use of acid solutions in the industrial environment causes degradation of materials. In recent decades, the use of corrosion inhibitors has become very essential. Objective: The objective of our study is to test the performance of meloxicam as a copper corrosion inhibitor in a nitric acid medium. Methods: The studies were conducted using the gravimetric method and density functional theory (DFT) at B3LYP/6-311G (d, p) level of theory. The inhibitory efficiency of the molecule increases with increasing concentration of Meloxicam, but decreases with increasing temperature. The adsorption of the molecule on the copper surface follows the Villamil model. Results: The thermodynamic quantities of adsorption and activation were determined and discussed. Quantum chemical calculations have allowed determining the molecular descriptors. Conclusion: There is a good agreement between the experimental and theoretical results. Electrochemical studies are envisaged.

Background: The parent molecule in the skeleton of this chalcone is the benzyloxy phenyl, which is linked to the chlorophenylpropen at C-3. The hydrophobic phenyl groups are naturally resistant to oxidation and reduction. Antiviral, antimalarial, antibacterial, anti-inflammatory, anticancer, antioxidant, antitubercular, and anti-Alzheimer activities are among the many pharmacological properties of chalcone derivatives. As a result, chalcone-based compounds are investigated using molecular docking and molecular modelling calculations to determine their suitability for drug formulation. Aims: To synthesise (2E)-3-[3-(benzyloxy) phenyl]-1-(4’-chlorophenyl)-2-propen-1-one [BPClPO] and perform DFT and molecular docking analysis of the synthesized compound to better understand its medicinal properties. Objective: The characterization of BPClPO is investigated in this study using various approaches, including wavefunction analysis and spectral analysis, which are associated with quantum chemical calculations to investigate its medicinal properties. Methods: The Gaussian 09W programme was used to perform computational chemistry calculations. The BPClPO's molecular structure was optimised, and the vibrational frequencies, Natural Bond Orbital (NBO), Fukui function, electronic properties and Nuclear Magnetic Resonance (NMR) chemical shifts were calculated using the B3LYP/6-311G (d, p) as the basis set. The VMD user interface and Multiwfn (3.4.1) software were used to conduct topological analyses of the Electron Localization Function (ELF), Localized Orbital Locator (LOL) and Reduced Density Gradient (RDG). The binding sites of active cancer proteins were calculated using the auto dock and auto grid. Results: Theoretical reaction path investigation was done for BPClPO to detect reactions from the parent chemical to the synthesized compound. Theoretical bond lengths and bond angles are compared with XRD values. Theoretical values of vibrations caused by electron-rich and electrondeficient centres were investigated. The electronic spectra of λmax were examined under UV-Vis light and the electron absorbance spectrum was absorbance wavelength and oscillator strength compared to theoretical values. The electron-rich carbon atoms are de-shielded in NMR, resulting in stronger fields and chemical shifts. The Harmonic Oscillator Model of Aromaticity (HOMA)and the retain ability of aromaticity in the addition and removal of electrons are examined in the Nucleus Independent Chemical Shift (NICS) study. The stability of the compound was investigated using Thermo- Gravimetric analysis and Differential Scanning Calorimeter (TG/DSC) analysis. Four cancer proteins with the reactive site were studied in docking simulations. Conclusion: The NBO analysis determined the intramolecular charge transfer within the molecule of high stabilization transition from C34-C37 donor to C35-C39 acceptor of (22.31 Kcal/mol) (π→π*) due to phenyl transition belonging to Cl atom in the ring. In the solvent phase, UV-visible spectra reveal a prominent peak at 300 λmax, with an absorbance range of intensity of 0.6983. (a.u.). According to TG/DSC experiments, the molecule begins to break around 290-370°C, and total decomposition occurs at 300°C. The molecule was found to have a higher bioactivity than and was employed related more to medicinal properties mechanism(s) of action in drug docking investigations.

Background: Parkinson's disease (PD) is a neurodegenerative pathology common in the elderly, and it may be related to several factors, such as excessive and continuous use of drugs, alcoholism, and cerebral ischemia, among others. Emphasizing that there is still no cure for PD, current pharmacological treatment aims to restore reduced dopaminergic activity in the central nervous system and manage symptoms. However, due to the different side effects caused by antiparkinsonian drugs, their use is recommended just when symptoms considerably impair professional performance or the patient's daily tasks. Therefore, studies for developing new drugs have been conducted, and natural products are gaining importance due to the possibility of discovering new bioactive molecules. In this sense, this research aimed to perform the in silico study of molecules of natural origin for treating PD. Methods: A search for molecules from medicinal plants was carried out; they underwent a pharmacokinetic and toxicological prediction with a subsequent molecular docking study coupled with the MAO-B enzyme and the dopamine receptor 2. Results: The ginsenosides compounds present an unfavorable pharmacokinetic pattern, which can be explained by their molecular mass, while the other molecules present average patterns, with the exception of kavains, which obtained very satisfactory results. When it comes to toxicity, the molecules curcumin, dihydrokavain, vitexin, kavain and tetrahydrocurcumin did not exhibit any toxic alert. As for the molecular docking study, the compound curcumin stood out with many interactions at many amino acid residues relevant to antiparkinsonian activity, both in the MAO-B enzyme and in the D2 receptor. Conclusion: Of 25 molecules of natural products, 3 are good candidates for studies of oral drugs, owing to their excellent pharmacokinetic profile and low probability of being toxic. The curcumin molecule has great notoriety, as it obtained relevant interactions with the two proteins studied in molecular docking, especially in the MAO-B enzyme.