Chemical Review and Letters

Abstract Piperidine is a heterocyclic chemical molecule that is forming by hydrogenating pyridine. In natural and pharmaceutically active drugs, the piperidine ring is an essential molecular component. Several crystal structures of piperidine-4-ones and their derivatives are reported for their medicinal value. While several methods of piperidin-4-one crystallization have been developed to obtain a crystal structure, novel approaches are still needed. A review of the synthesis and crystallization procedure of piperidin-4-ones and its derivatives is outlined in this review paper.

Abstract Abstract

The widespread of dengue infection globally has become a great source of concern especially to developing countries with limited resources to control the spread of the dengue virus vector as such infection characterized by fever, joint pain, etc. may progress to a fatal phase such as dengue hemorrhagic fever and organ failure or dengue shock syndrome. An in-silico method using the DFT approach was employed for the geometric optimisation of phthalazinone derivatives with previously established interaction with NS2B-NS3 protease of dengue virus. Herein, molecular docking was employed to evaluate their biochemical interactions with dengue virus serotype 2 protease NS-5 as multi-target. Likewise, the ADME/PK property of the studied compounds was investigated. The molecular docking calculation showed that the previously reported compound 21 with the best potency against NS2B-NS3 protease had the best docking score of -9.0 kcal/mol against NS-5 protease. The physicochemical and ADME/PK properties result revealed that these compounds are orally bioavailable with high gastrointestinal absorption, and are all inhibitors of CYP-3A4 and CYP-2D6 except compound 7 which is a non-inhibitor of CYP-2D6. Also, all the compounds are substrates of P-glycoprotein. The information derived from this study can be utilized in the drug discovery process to improve the anti-dengue activity of the studied compounds. This study would provide physicochemical and pharmacokinetics properties required for the identification of potent anti-dengue drugs and other relevant information in drug discovery.

Abstract Phytochemicals are chemical compounds produced by plants during the natural metabolic processes to resisting them fungi, bacteria and plant virus infections, and also consumption by insects and other animals. Phytochemicals is generally used to describe plant compounds that are under research and are often referred to as secondary metabolites. Some phytochemicals have been used as poisons and some others as traditional medicine and Nutrition. The aim of present study was to update a comprehensive review published on Urtica dioica which includes phytochemical and pharmacological synthesis. Urtica dioica or stinging nettle which is Urticaceae family herbaceous perennial, usually grows in temperate regions such as Europe, some places of Asia and western North Africa, New Zealand and North America. Its stem and leaves covered with hairs called trichomes which act like hypodermic needles and inject histamine and some other chemicals. Burning sensation during contact and contact urticaria (contact dermatitis) is visible because of it. A lot of bioactive phytochemical compounds have been identified in the methanolic extract of it.

Abstract The current research targeted to estimate total sugars, fats, proteins, phenols, and antioxidant activity of ethanolic extract of five date varieties (al-Tabouni (TAB), al-Bakrari (BAK), al-Aami (AAM), al-Hamouri (HAM), and al-daqla (DAQ)) available in Libya. Also, phytochemical screening for ethanolic and aqueous extracts were performed. In general, the two extracts were rich in carbohydrates, proteins, phenols, flavonoids, alkaloids, and glycosides. However, steroids didn’t exist in aqueous extract and saponins in both extracts. Total sugars were estimated by spectrophotometric methods, the proteins using the Kjeldahl method, and fats by the Soxhlet device, and their percent were ranged between 49 - 66%, 1.43 - 2.25, 0.10 - 0.25% (w/w) for sugars, proteins and fats, respectively. The total phenols were also estimated using the Folin reagent method, where the results are expressed as mg (gallic acid equivalent) per g (extract) and ranged from 13.5 to 20.5 mg/g, and the highest level was in the DAQ variety. The DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging method was also used to estimate total antioxidants where the two largest levels were found in the DAQ and HAM varieties with concentrations of 10.68 and 10.63 mg (ascorbic equivalent)/g (extract), respectively. DAQ extract has reduced the 50% of DPPH at lower concentration of 0.110 mg/ml (IC50). Furthermore, good positive correlation was found between total phenols and DDPH in ethanolic extract.

Abstract This study aims to Gentian Violet (G.V) removal using activated carbon (AC). The AC was obtained by chemical activation of mango kernel shells (Adams) with potassium hydroxide (AC-BK), at 600°C and for 2h. AC-BK has been characterized by physico-chemical analyses such as: specific surface area, zero charge point pH, surface functions and morphology. With a specific surface area of 534 m2.g-1, AC-BK was used to remove Gentian Violet (G.V) in batch mode and under magnetic stirrer at 150 rpm. Thus, the effect of contact time, initial concentration, pH and temperature of the reaction medium was studied. The maximum abatement rate for G.V was 96.5 % at temperature of 25 °C and pH = 6. Among the models discussed, the Freundlich model seems to better reflect the elimination of G.V. by AC-BK with a coefficient of determination very close to 1 (R2 > 0.99). In addition, this reaction is well fitted by pseudo-second order kinetics with a regression coefficient of 0.99. The adsorption of G.V by AC-BK is characterized by a multilayer on the surface of the AC. These results suggest that AC-BK was effective in removing of G.V with a maximum adsorption capacity of 160. 10 mg.g-1 and could therefore be tested for the remediation of dye-laden industrial effluents.

Abstract In this work, the possible apply of a hexa-cata-hexabenzocoronene HCor as anode material was studied for Li-ion batteries (LIBs) using the B3LYP/6-31G* level. The planar structure of HCor is less stable (by about 0.243 hartree) in comparison with the twisted structure. The Li cation and neutral are suitably adsorbed high up the middle of a HCor hexagonal ring with the adsorption energy of -120.3 and -2.7 kcal/mol, respectively. The calculated specific storage capacity of HCor is 450.1 mAh/g and the great cell voltage is 2.63 V generated by the interaction between Li+ and HCor. The HCOR is considered an ideal candidate to be used as an anode material in LIBs because of high storage capacity and ion mobility.

Abstract The requirement for novel adsorbents from inexpensive sources, directs this research towards innovation of new adsorbent materials through extracting and modifying cellulose fibres from peanut shells and corn stalk. The processes involved delignification, alkaline hydrolysis, acetylation of pure cellulose and the adsorption of Lead Pb2+. The adsorbents obtained are pure celluloses of peanut shells (PSC), Corn stalk (CSC) and Acetyled Celluloses of Peanut Shells (PSCA) and Corn Stalk (CSCA). The Structural and functional properties were analyzed by Fourier transformed infrared spectroscopy, FTIR and Atomic Absorption Spectrometer, AAS. The four adsorbents all exhibited high removal percentage of Lead from the solutions. However, acetyled Cellulose of peanut shells exhibited the highest adsorptive capacity of 397.5 mg/g with final Lead (Pb) concentration of 0.125 mg/L, the removal of Lead from solution amounted to 99.3% as compared to the other adsorbents. This research proved the efficiency of agro waste cellulose acetate for use as novel adsorbents through the Lead Adsorption. An extensive exploration in researches involving biodegradable waste materials is required to utilize this source and control environmental pollution.