Advanced Journal of Chemistry, Section B: Natural Products and Medical Chemistry
Volume:2 Issue: 1, Winter 2020

Recent developments in computer hardware and software, in addition to modern algorithms, have led to new era of scientific laboratories; called Lab-in-Silico. The simulation protocols have been evaluated for several types of chemical matters and reactions to simulate the real systems in the computers. There is no doubt in the importance of efforts in the experimental chemical laboratories to yield novel materials, but the simulation processes could push ideas into products at the higher accuracy. Knowledge about what happens during the reactions and the corresponding mechanisms is always an important task for those scientists working on the mystery of chemistry.

This review aims to provide overall aspects of the history, biology, chemistry and the total synthesis of Aflavinines.  The origin of this molecule traced back from the isolation and structural elucidation by Clardy and co–workers in 1980 [Tetrahed. Lett. 1980;21:243–246]. Most of the previously published total syntheses were covered in a brief summary and the key points of each work are highlighted. Moreover, various antiinsectant and antiviral Aflavinines congener are presented. This review is almost the first in Aflavinine topics covering all aspects in brief, to the best of our knowledge.

An analytical method has been proposed based on the separation and determination of selenium(IV) ion using polyurethane foam as a solid sorbent coated with ammonium pyrrolidine dithiocarbamate (APDC). Different factors including the pH of sample solution, time of extraction, volume of sample, and amount of the loaded and unloaded polyurethane foam were examined and a preconcentration factor of 5 was obtained. The interference effects of some additional salts in the solution such as NaCl, FeCl3, BaCl2, CH3COONa and Na2SO4 have been investigated. The improved limit of detection (LOD) for the method is 0.064 mg/L. The improved LOD is much lower than the LOD of FAAS and approaching the LOD of GFAAS. The new developed procedure SPE-FAAS has been Found to be successful in separating the complex matrices (human hair, bovine liver, pork liver, bovine muscle) and pre-concentrating selenium ion from real blood sample. The developed method for solid-liquid extraction is convenient, simple, sensitive and of low costs.

The interactions between boron carbide (BC) nanocluster of B16C16 and H2O, NO2, CO, and CH4 small molecules were investigated by using density functional theory (DFT) computations to exploit the structural and electronic properties of the adsorbate/cluster complexes. The calculated adsorption energies of the most stable states are -16.6, -0.17, -1.28, -0.18 eV for NO2, CO, H2O, and CH4 molecules, respectively. Meanwhile, the interactions between CO and CH4 molecules and the cluster induce dramatic changes to the cluster electronic properties so that the molecular orbital (HOMO/LUMO) gap of cluster decreased its original value. It was shown that the phenomenon leads to an increment in the electrical conductivity of the cluster at a definite temperature. Furthermore, it is revealed that the adsorptions of NO2 and H2O molecules have no significant effects on the electronic properties of the cluster. Thus, this work suggests that the investigated B16C16 nano-cage could work as a selective gas sensor device towards CO, CH4, NO2 and H2O molecules.

The main purpose of present study is evaluation of structural and medicinal properties for Withaferin A (WIT) using density functional theory (DFT) method. All studies are done via computational chemistry methods using Gaussian 03 and Molegro Virtual Docker (MVD) software packages and SwissADME web-based tool. Molecular structure of WIT was optimized at the B3LYP/6-311++G(d,p) theoretical level of DFT. The reactivity and stability properties of the optimized molecule were explored via global reactivity indices. Calculating the reactivity indices using energies of frontier molecular orbitals (FMOs) showed that WIT is stable against the oxidizing agents in the cell and has low reactivity against the biomolecules. On the other hand, the docking analysis data indicated the steric interactions play important role in WIT binding to beta-Tubulin via the residues Tyr224, Cys12, Gln11, Asn101, Gly143, Gln15, Gly144, Asn206, Gly142, and Asp179.

The properties for 2(5H)-furanone and 2(5Methyl)- and 2(5Phenyl)-furanone derivatives have been explored by computational chemistry approach. The subatomic unit calculations have been done to optimize the models and to evaluate their corresponding properties, in which several achievements have been seen for the investigated models. The energy levels of molecular orbitals indicated the importance of structural modifications for obtaining better electronic properties. To this aim, total energy, energy levels of the highest occupied and the lowest unoccupied molecular orbitals, energy gap, ionization positional, electron affinity, hardness, softness and dipole moment have been evaluated in addition to the original molecular weight and LogP parameters. The results revealed better reactivity and antioxidativity for 2(5Phenyl)-furanone in comparison with two other models proposing it for various possible applications in biological systems. Moreover, hardness and softness properties were also seen more favorable for this model. As a conclusion, the importance of furanone could be very much increased regarding structural modification, which could be very well investigated by the computational chemistry approach.

Non-covalent interactions of N-(4-carboxyphenyl)phthalimide (CPP) with carbon nanotubes (CNTs) have been investigated to see the effects of interactions on the properties of CPP, which is a medicinal compound. Two models of (3,3) armchair and (6,0) zigzag CNTs have been considered in this work. All structures have been optimized by density functional theory (DFT) calculations to evaluate the corresponding properties. Moreover, quadrupole coupling constants (CQ) have been evaluated at the atomic scale for the optimized structures. The results yielded stabilized CPP@CNT hybrids by effects of hybridization on the properties of both of CPP and CNT counterparts. The CQ parameters also indicate that the carbon atoms are very much important to detect the type of CNT whereas other atoms showed almost the same effects at the same situations. As a result, the CPP could be very well hybridized with the CNT through non-covalent interacting system.