Challenges and Advances in Chemical Science Vol. 2

Objective: A simple and sensitive extractive visible spectrophotometric method is developed for the assay of Triprolidine Hydrochloride using Sodium nitroprusside.

Methods: Based on color development with amino groups, presence, which is basic, may be due to the formation of inner complex replacing H₂O by the tertiary amino group present in the drug.

Results: The colored products exhibit absorption \(\lambda\)_max at 447 nm. Regression analysis of Beer–Lambert plots showed good correlation in the concentration ranges (40–240) \(\mu\)g/ml and correlation coefficients are 0.994. The Sandell’s sensitivities 2.6373×10^-2 (1 mole cm^-1) and molar absorptivity value are 1.1938×10⁴ (g cm^-2). Recovery studies are found to be 99.708–99.786.

Conclusion: The method can be applied successfully for the estimation of the drug in the presence of other ingredients that are usually present in formulations. The proposed method reports a new way for the determination of Triprolidine Hydrochloride (TPH) in pharmaceuticals.

Coulomb and Newton "fundamental forces" are consequences of the nonlocal organization of energy currents, and these consequences with inverse square accelerations cannot change the steady quantization of an extended charge, including its metric distributions in the chemical bonds of micromolecules, mesoscopic clusters and macroscopic superconductors. Based on the Bohr-Sommerfeld quantization of charged particles, there are no theoretical grounds for developing SQUID-type instruments to calculate electric and gravitational interactions-consequences with quantum precision. The self-coherent nonlocality of isolated molecules and holonomic crystals maintans the metric organization of curved space-time with material 3D space under Euclidean geometry. The metrical shaping and 4D quantization of the elementary material continuum  quantitatively introduce the Sommerfeld constant and the Plank length.

The theoretical investigation of inclusion complexation of amide-imidol  tautomer   of  two  guest  molecules  benzanilide (BA) and fast violet B (FVB) with \(\beta\)-cyclodextrin (\(\beta\)-CD) using DFT  B3LYP 3-21G  method in the gas phase. Benzanilide has no substitution in the basic skeleton and the other selected compound substituted with three groups such as –NH₂, -CH₃ and –OCH₃ group in the same aromatic ring. The tautomer of two selected compounds was formed the stable inclusion complexes with the \(\beta\)-CD supramolecule. The theoretically calculated complexation energy was observed the negative value for all the inclusion complexes. This method was applicable to determine the structural assignment of the inclusion complexes between BA, FVB and \(\beta\)-CD.

Cheminformatics is one of the most emerging fields that add cutting edge state of information to the science. This work presents an updated report of the recent literature in Cheminformatics and related fields that could be of help during the process of Drug Design and Discovery and for the development of therapeutic drugs.

The fulfillment of the ”Koopmans’ theorem in DFT” or KID methodology is verified by means of the calculation of several global descriptors arising from Conceptual DFT. They have been calculated through a \(\triangle\)SCF procedure, and by means of the HOMO and LUMO frontier orbitals. The latest Minnesota family of density functionals has been considered and three fluorescent DNA staining dyes have been studied: Hoechst 33258, Hoechst 33342 and Hoechst 34580. On the basis of the obtained Conceptual DFT indices, a series of descriptors have been devised in order to determine the accuracy of each model chemistry considered here in the verification of the mentioned theorem. It is shown that the only density functionals that fulfill this task are those denoted as range-separated hybrids (RSH), while the local density functionals are not useful at all.

Alzheimer's disease is a progressive nervous system disorder linked to the presence of extracellular senile plaques. Extracellular senile plaques are mostly made up of 40-42 residues of amino acid-containing polypeptides known as  \(\beta\)-peptides. The Theory of Chemical Reactivity, MEDT (Molecular Electron Density Theory), and Conceptual DFT were used to find descriptors that allowed QM:MM calculations with the ONIOM methodology to predict the sites of reactivity of the Alzheimer amyloid \(\beta\)-peptides A\(\beta\)40 and A\(\beta\)42.  

Using cyclic voltammetry, differential-pulse voltammetry, and impedance spectroscopy, the electrochemical behavior of a Nafion-1,10-phenanthroline-modified carbon paste electrode (CMCPE: Chemically Modified Carbon Paste Electrode) immersed in a supporting electrolyte 0.1 mol.L^-1 acetate buffer solution (pH 4.5) containing iron(II) metal ion was investigated. The optimal analytical parameters for determining iron(II) metal ions (preconcentration potential and time, pH, electrode rotation) have been evaluated and correlated with the surface morphology of the CMCPE surface, the surface chemical composition analysis, and the impedance measurements of the CMCPE immersed in the supporting electrolyte. The experimental impedance values were fitted to an equivalent circuit model using a simple methodology based on a redox polymer-modified electrode. It was shown that among various potentials used for iron(II) accumulation in the Nafion-film, the potential of +1.3 V vs. Ag/AgCl/3 mol. L^-1 KCl allowed a better differential-pulse determination of the examined iron(II) metal ion in the supporting electrolyte. With the determination of the iron(II) metal ion in groundwater samples collected in a community on the outskirts of Ouagadougou, the Capital of Burkina Faso, the research was expanded to real applications.

Due to the extreme significant nonlinearities in the system's behaviour, pH regulation is one of the most difficult issues in the process industry. Various ways to pH control have been proposed in the literature. The regulation of pH using an internal model controller for a pH process based on a neural network model is proposed in this paper.  Modeling the pH process is thought to be a tough undertaking since it requires understanding of the components and their nature in the process stream to simulate its dynamics. In this paper, a neural network model based on the first principle equation of nonlinear pH is suggested and applied to effectively control the pH process utilising IMC based PI.

In geometry, Waclaw Sierpinski described fractals such as Sierpinski triangle, Sierpinski gasket and Sierpinski carpet. In this work, Sierpinski triangle is used to find any equation between the atomic number and the atomic weight of elements in the periodic table. First by using Matlab program, an algorithm is written to create a right angle triangle and an equation between the atomic numbers and atomic weights. Also, the resulted the atomic numbers and atomic weights are compared with the real ones. Then this original triangle is divide to 8 smaller triangles on the hypotenuse of the original triangle to get more accurate results and reduce errors of the atomic numbers and atomic weights which are shown in tables. Finally, the resulted equation of correlation between the atomic numbers and the atomic weights of elements based on Sierpinski triangle is determinate to calculate the atomic weights of the future discovered elements in eighth period. This work is a combination research in chemistry and geometry.

Water is a very important component of biochemical processes in the body. Drinking water should conform to standards set by the World Health Organization. Water is a life sustaining drink and it is essential for the survival of all organisms. The provision of safe drinking water is a very important public health priority. Most of the diseases in developing countries are caused by the consumption of contaminated water. The concentrations of six heavy metals and six trace metals were determined in sachet water samples and bottled water samples obtained in Lagos markets, Nigeria using Atomic Absorption Spectrophotometry (AAS). Lead concentrations were below the maximum permissible levels except in Bevap sachet water, Osan bottled water, Christo bottled water and Cway bottled water samples. Cadmium was not found in most of the water samples except in Pringad bottled water, Sunar bottled water and Cway bottle water samples together with Nimbus satchet water. These levels were above the maximum permissible levels of the WHO. Chromium was found present in all the water samples analyzed although in trace amounts.  All other heavy metals analyzed were below the maximum permissible levels. The water samples also contained iron, manganese, calcium, magnesium, sodium and potassium in concentrations that are not harmful to the body. Examination of heavy metals in the water samples showed traces of lead in five sachet water samples and seven bottle water samples together with cadmium in three satchet water samples and three bottled water samples. This may be harmful after being consumed for a long time by the populace.

Adsorption of the pollutant gas CO on B₁₂P₁₂ nanocage surface is studied through density functional calculations. HOMO and LUMO energy levels, binding energies and  energy bond gaps of three possible configurations of CO on pristine B₁₂P₁₂  has been calculated by means of B3LYP and M062X functional with 6-31g⁺ basis set. The results showed that there is none or very slight adsorption of CO molecule by pristine B₁₂P₁₂.To overcome the fault, CO adsorption is investigated on Al and N doped B₁₂P₁₂ nanocage with the same method and basis set. The electronic and structural parameters like HOMO and LUMO energy levels and binding energies of possible configurations are calculated and showed that doped B₁₂P₁₂ with both Al and N atoms have increased about % 1.7 with CO molecule which also indicates more Vander Waals attraction between CO and Al and N doped B₁₂P₁₂ nanocage.

Conductivity and viscosity measurements at 298.15 K were used to investigate the micellization behaviour of anionic surfactant sodium caprylate (SCAP) and cationic surfactant cetyl pyridinium chloride (CPC) in the presence of polymers (polyvinyl pyrrolidone, Tween-20, Tween-40, Tween-60, and Tween-80) in aqueous solutions. For both surfactants, the critical micellar concentration (CMC), critical aggregation concentration (CAC), and polymer saturation point (PSP) have been determined in water and aqueous polymer solutions of various concentrations. The CAC values for both surfactants decreased somewhat as the polymer concentration increased, however the PSP values stayed nearly constant.

The degree of ionization (\(\alpha\)) and standard free energy of transfer (\(\triangle\)G^o) have been estimated. \(\triangle\)G^o values were discovered to decrease as polymer concentrations increased. The relative viscosity, \(\eta\), for the above systems has been determined as well at 298.15 K in various polymer solutions. The maximum value of \(\eta\)_I/\(\eta\)_I,max (\(\eta\)_I is the interaction viscosity) as a function of R (ratio of concentration of surfactant to that of polymer), shifts towards the lower values of R with the increase in polymer concentration. The findings were explored in terms of the numerous interactions that take place in these systems.