Chemical Review and Letters
Volume:3 Issue: 3, Summer 2020

In this study, biodegradable composite starch/tragacanth gum/Nanoclay (St/TG/Clay) film was prepared. The basis of the film was wheat starch, which tragacanth gum was added at three levels (0.2 and 0.5% by w/w) and clay nanoparticles at three levels (0.1, 0.5 and 3% by w/w). Physicochemical properties of the film, including thickness, water solubility, moisture content, and vapor vapor permeability (WVP), were investigated. The mechanical properties of the films, including the tensile strength and elongation of the films, and the color characteristics of the films were examined. The results showed that adding tragacanth to the starch film increased the thickness, moisture content and permeability of the water vapor and reduced its solubility. The addition of tragacanth to the starch film increased tensile strength and elongation. The addition of tragacanth reduced the transparency of the films. Adding clay nanoparticles to starch film increased the water content, reduced water vapor permeability, and reduced solubility, but adding nanoparticles increased the thickness. Nanoclay increased the tensile strength of the films and reduced the elongation. The lightness of the films decreased with the addition of nano-clay, and the factor b, which indicated the yellowness of the film, increased. In general, it can be concluded that the addition of tragacanth and Nanoclay improves the physical and mechanical properties of starch film.

Dengue infection is a major public health challenge in several parts of the world, especially the sub-tropical and tropical regions. The development of agents that are able to inhibit the dengue virus (DNV) replication are therefore of utmost significance. I. tinctoria is one of the most investigated Chinese herbs, which has been recognised to be effective in the treatment of dengue fever. However, the mechanisms through which it exhibits such biological activity of great importance are still unclear. A total number of about 27 compounds isolated from I. tinctoria leaves which have been identified and reported in the literature to be effective against dengue fever were investigated for their inhibitory potencies against dengue virus as novel drugs for treating early attacks of dengue fever. The compounds were optimized by employing a method of Density functional theory (DFT) and a basis set of B3LYP (6-31G**). The results of Molecular docking investigation between the compounds and the dengue viral protein (PDB: 6MO1) revealed that three of the compounds (GB-20, GB-19, and GB-6) possessing best binding energy in of -27.051, -26.193 and -24.664 kcal/mol respective were observed to inhibit the target through hydrogen bonds and hydrophobic interactions with amino acids residue of the protease binding site. The results of these studies would offer relevant insight into structural requirements for the development of effective and a specific therapeutic treatment against dengue virus infection.

In this research, the performance of boron nitride nanocone for the detection and removal of ampicillin was investigated by infra-red (IR), natural bond orbital (NBO), frontier molecular orbital (FMO) computations. The calculated values of adsorption energy showed the interaction of ampicillin with BN nanocone is experimentally possible. The calculated values of Gibbs free energy and thermodynamic equilibrium constant showed the adsorption process is spontaneous and irreversible. The calculated values of enthalpy changes and specific heat capacity showed ampicillin adsorption is exothermic and BN nanocone can be used for the construction of a new thermal sensor for the detection of ampicillin. The effect of temperature on the thermodynamic parameters was also evaluated and the results indicated ampicillin adsorption is more favorable in room temperature. The NBO results demonstrated in both of the studied configurations a monovalent chemical bond is formed between the nanostructure and the adsorbate and the interaction process is chemisorption. The DOS spectrums showed the bandgap of BN nanocone increased from 1.888 (eV) to 7.030 (eV) which proved this nanomaterial is an appropriate electrochemical sensing material for detection of ampicillin. Some important structural parameters such as dipole moment, electrophilicity, maximum charge capacity, chemical hardness and chemical potential were also calculated and discussed in detail.

Trace elements are minerals present in living tissues in minute quantities. Some of them are known to be nutritionally essential and the remainder is considered to be nonessential. The body requires certain essential elements and their deficiency or excess may result in serious dysfunction of the body and even death in extreme cases. The low intakes dietary of trace element produce changes in biochemical pathways that can raise the risk of diseases over time. On the other hand, excessive levels, a level higher than needed for biological functions, of these elements can be toxic for the body health. This review evaluates the role and importance of the essential trace element in the human organism. The potential importance of key essential trace elements; Magnesium, Manganese, Iron, Zinc, Copper, Cobalt, Iodine, Selenium, Nickel, Molybdenum and Chromium; and nonessential trace such as Cadmium, Lead, Arsenic and Mercury are discussed.

The cotton whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an important pest of cotton which by transmitting plant pathogenic viruses cause damage and reduce lint quality. To reduce the use of chemical insecticides, effects of ZnO nanoparticles, Kaolin alone or in pairwise combination with NeemAzal-T/S against egg and second instar nymph of B. tabaci and pupae of its parasitoid Eretmocerus mundus Mercet were evaluated. The LC50 values of ZnO NPs, Kaolin and NeemAzal-T/S against eggs and nymphs of B. tabaci were 7.49 mg L-1, 24.89 g L-1, 6.83 mg L-1 AZA and 6.93 mg L-1, 18.36 g L-1 and 6.00 mg L-1 AZA 3 days after treatment, respectively. The LC50 values of ZnO NPs, Kaolin and NeemAzal-T/S against E. mundus were 11.30 mg L-1, 41.59 g L-1, 36.90 mg L-1 AZA, respectively 3 days after treatment. In the laboratory conditions, ZnO + NeemAzal and Kaolin + NeemAzal exerted a higher level of control on eggs and nymphs of the pest than either alone, while they had a lower level of negative effects on the parasitoid pupae, too. In the field conditions and at 7 DAT, Kaolin + NeemAzal was the most effective treatment on eggs of the pest, causing a 67.43% reduction, while NeemAzal-T/S was the most effective treatment on nymph (86.52% reduction), which was not different with ZnO + NeemAzal and Kaolin + NeemAzal. NeemAzal and ZnO exerted the highest and lowest mortality on pupae of the parasitoid, respectively. Based on the field studies, ZnO NPs at 20 mg L-1, Kaolin at 30 g L-1, NeemAzal-T/S at 15 mg L-1 AZA and mixing equal volumes of NeemAzal-T/S (7.5 mg L-1 AZA)+ZnO NPs (10 mg L-1) and NeemAzal-T/S (7.5 mg L-1 AZA)+ Kaolin (15 g L-1) can be suitable candidates in IPM programs of B. tabaci field condition.

The management of HIV in the human body has been a major research area in the quest to either find the cure or the preventative scientific measure. The quest to manage the virus has been successful using some organic molecules which target one or more of the stages of the replication cycle of HIV rendering it inhibited to continue infecting other host cells. However, the approach is now moving to use of transition metal complexes to manage the HIV infection in the host cells and this review highlights the relevant contributions of such as HIV/AIDS inhibitors. There have been increasing number of reports on the trends for transition metal complexes with anticancer and antimicrobial activity hence this probed the need of such a review. Complexes of vanadium, manganese, iron, copper, cobalt, nickel, zinc, ruthenium, platinum and gold have been reported to be active against HIV-1 virus. The complexes discussed in this review showed anti-viral activity compared to the vehicle control.