Volume 96, Issue 5 - Special Issue: Virtual Conference on Chemistry and its Applications 2023 (VCCA-2023)

Oxidative degradation of 1,2-dichlorobenzene using different loadings of metal (Mn, Ni, V, and Fe) supported on CeO 2 was studied. All metal (Mn, Ni, V, and Fe) loaded CeO 2 catalysts were synthesized using the method called wet impregnation and the as-synthesized catalyst materials were characterized using different analytical instruments such as FT-IR, SEM-EDX, XRD, BET, ICP-OES, and TEM methods. The oxidation reactions of 1,2-dichlorobenzene were studied by bubbling substrate (1,2-dichlorobenzene) with ozone (0.0794 mg/L) into a glass reactor via a porous bubbler of porosity 2 over a period of 24 h. A 2.5 % Fe/CeO 2 catalyst was found to be the most active catalyst with a percentage conversion of 62 % within 24 h of ozonation. The oxidation products were identified using GC-MS and FT-IR spectroscopy was used to study the functional groups present in the ozonation product. The ozonation products that were identified are mucochloric acid and 3,4-dichloro-2,5-furandione. All the V loaded on CeO 2 catalysts produced 100 % mucohloric acid at the end of ozonation (24 h).

The purpose of this research is to improve the stability of α-amylase from Aspergillus fumigatus by chemical modification with citraconic anhydride. The α-amylase was isolated using a centrifugation technique, followed by purification using precipitation and dialysis of ammonium sulfate salt. The experimental results demonstrate that the purity of purified α-amylase is 13.41 times higher than that of the crude extract. A significant increase in the optimum temperature was also achieved, in which the optimum temperature of 50 °C was found for native α-amylase, while for modified α-amylase, the optimum temperature of 60 °C was found. Similarly, an increase in half-life was also evident, which is 38.72 min found for the native enzyme to 256.67–330.00 min for modified α-amylase, depending on the volume of citraconic anhydride used. Modification also resulted in increased free energy values ( ΔG i ) from 104.348 for the native enzyme to 109.585–110.281 kJ mol −1 for modified α-amylase, indicating that modified α-amylase is stiffer than native α-amylase. The results obtained in this work demonstrate that citric anhydride is a very promising modifying agent to improve the stability and performance of α-amylase enzyme isolated from A. fumigatus . The findings of this study also offer an opportunity for the application of citric anhydride for other enzymes.

For a long time, fossil fuel has been a part of our everyday lives and has constantly led to the emission of carbon dioxide (CO 2 ) into the environment. The release of methane (CH 4 ) into our surroundings can be caused by the decomposition of organic wastes produced by our daily activities; CH 4 produced by human activity is responsible for at least 25 % of global warming. CH 4 is a known potent greenhouse gas that can trap about 35 times more heat than CO 2 . These greenhouse gases play a role in climate change and global warming. It, therefore, becomes important to explore measures for decarbonizing our environment. Biomethane production using our generated waste is a promising decarbonization approach with significant potential for mitigating greenhouse gas emissions. This paper overviews potential biomass methanation feedstocks and investigates several technologies, such as anaerobic digestion, combined pyrolysis and methanation, and combined gasification and methanation. SWOT analysis of waste conversion to biomethane was conducted, and important points related to the scaling-up of biomethane production processes were outlined. Also, insights into prospects for promoting biomass methanation deployment were provided. In conclusion, biomass methanation has great potential for producing sustainable energy. Hence, collaboration between industrialists, researchers, government agencies, and stakeholders including an understanding of the financial investments, return on investments, or potential subsidies and incentives could enhance the practicality of the proposed solution. Research and development should be continuously carried out as they are necessary to scale up and promote the technology. Also, there should be technical training for stakeholders as it is essential for the smooth development of the sector.

Reasoning in terms of molecules has since long become fully embedded in any chemistry discourse. On the other hand, students’ familiarization with the molecular level in pre-university instruction is not always satisfactory, and their ability to view chemical phenomena in terms of what molecules do may not reach the extent and quality that would be needed to ensure effective conceptual understanding. Students may remain uncertain about the interpretation of the molecular features of a number of phenomena even through undergraduate instruction. Removing uncertainties and promoting comfortable familiarization is increasingly becoming an imperative for chemistry education, in view of the novel central role that the molecular level is acquiring not only for the customary interpretation of phenomena, but for the high variety of applications that have been blooming in recent years. Consequently, learners’ familiarization with the world of molecules needs to become more informative and complete. It is equally important that the information that they acquire about molecules be consistent with the modern descriptions, which are based on quantum mechanics. This requires accurate search for optimal balances between the need to simplify the terms of the descriptions in order to make them accessible to leaners according to the different levels of chemistry learning, and the simultaneous need to maintain adequate conceptual rigour. The present work outlines approaches which have proved viable and effective, and which rely on accurate use of language and visualization as the major explanation resources.

The amide bond is one of the most important structural units in nature, as it is part of the backbone of peptides and natural proteins, as well as some essential amino acids, DNA, RNA, hormones, or vitamins found in the body. Furthermore, this bond is significant in the pharmaceutical industry due to its presence in the structure of numerous APIs contained in drugs. This paper reviews the most important methods collected in the bibliography for the preparation of this moiety.

The surface tension of ionic liquids with the tris(pentafluoroethyl)trifluorophosphate (FAP) anion were measured using a home-built surface tensiometer. A high-vacuum line was used to pre-evacuate the ionic liquids prior to analyses, ensuring that the samples were free of dissolved gases, water, and volatile impurities. Using the pendant drop method, measurements were performed in a custom-built surface tension vacuum or gas cell, in the presence of nitrogen and carbon dioxide gas. To calibrate the instrument, surface tension measurement of known liquids was also performed. Results show that the presence of saturated carbon dioxide led to the lowering of measured surface tension values, indicating the adsorption of CO 2 on the ionic liquid surface.

Prostate cancer remains a significant global health challenge, necessitating the exploration of novel therapeutic approaches. Androgen receptor (AR) signaling plays a critical role in prostate cancer progression and is a primary target for therapy. This study investigates the potential of phytochemicals from Capsicum annuum (Bell pepper) along with two common standand drugs (Apalutamide and Enzalutamide) as inhibitors of the human androgen receptor (AR) and prostate-specific membrane antigen (PSMA). Utilizing computer-aided drug design techniques, molecular docking studies were conducted to evaluate the binding affinities of selected ligands against AR (PDB ID: 1XOW) and PSMA (PDB ID: 2XEI), their ADMET properties, drug-likeness, oral bioavailability, and bioactivity profiles were also examined. Coumaroylquinic acid and 5-O-caffeoylquinic acid methyl-ester emerged as top-performing ligands, demonstrating strong binding affinities of −9.4 kcal/mol and −9.2 kcal/mol, respectively, against PSMA. Additionally, molecular dynamics simulations provided insights into the stability of protein-ligand complexes, with Coumaroylquinic acid exhibiting a stable binding conformation throughout the simulation. These findings suggest the potential of C. annuum phytochemicals, particularly Coumaroylquinic acid and 5-O-caffeoylquinic acid methyl-ester, as promising inhibitors of PSMA. Moreover, other ligands (Caffeoylglucoside and 1-O-galloyl-beta- d -glucose) identified in the study demonstrate interactions with AR, highlighting a multifaceted approach to prostate cancer treatment. Overall, this study underscores the potential of C. annuum phytochemicals as a source of novel therapeutic agents for prostate cancer, laying the groundwork for further lead optimization efforts.

Mathematics constitutes a fundamental key for the description and understanding of many phenomena. The chemistry discourse incorporates mathematics in various ways and instances. At educational level, interchanges occur in two directions: mathematics provides support for clearer understanding of chemical phenomena, and the level at which students use the relevant mathematics is an indication of the clarity of their conceptual understanding in chemistry. The present work focuses on an issue for which mathematics tightly links to the conceptual understanding of physical terms – the issue of independent and dependent variables. The definition is in principle well known. On the other hand, the distinction between the two types of variables and their roles is not always clearly underlined at explanation level, and is often not sufficiently internalised by students. This results in a variety of misunderstandings and errors. Careful analysis of students’ works enables the identification of errors that can be tracked down to unclear distinction between the dependent and independent variables in a given context; such errors appear in several areas of chemistry, at both undergraduate and postgraduate levels. The present work considers and analyses a number of representative examples, highlighting the impact of their unclear distinction and the ensuing importance of devoting specific attention to it. Selected addressing approaches from direct experience are included and their outcomes discussed.

Various derivatives of cinnamic acid have been reported to possess significant activities such as antioxidant and hepatoprotective, and neuroprotective activities. Interestingly, testicular toxicity has been linked to several causes, with oxidative damage being one of the pathophysiological mechanisms. 3-(4-methoxyphenyl) acrylic acid ( 1 ), a derivative of cinnamic acid, was synthesized and then investigated for its effects on iron-induced testicular injury and oxidative stress via ex vivo and in silico studies, respectively. Evaluations were done on KAD-1’s FRAP, DPPH free radical scavenging activity, and iron chelating potential. Through the ex vivo incubation of tissue supernatant and 0.1 mM FeSO 4 for 30 min at 37 °C with different concentration of 1 , oxidative testicular damage treatments were induced. The scavenging property of 1 increases significantly ( p  < 0.05) as the concentration increases when compared with the standard quercetin. The MDA, CAT, ATPase, and ENTPDase activities were reduced when testicular damage was induced ( p  < 0.05). The group treated with 30 mg/mL had the highest level of MDA. A significant rise in GSH level and activity of SOD were observed. The result obtained indicated that 1 has the potential to prevent oxidative testicular toxicity, as evidenced by its capacity to control nucleotide hydrolysis and reduce oxidative stress. Overall, the results of this experimental study point to some possible uses of 3-(4-methoxyphenyl) acrylic acid ( 1 ) in the prevention of oxidative testicular dysfunction. Therefore, 3-(4-methoxyphenyl) acrylic acid ( 1 ) would be a good product in developing a medication to alleviate male infertility.

Density functional study (DFT) is performed for understanding the reactivity, aromaticity, and UV-visible absorption spectra of chrysene-based materials. Effect of BN doping on the said parameters are analyzed along with the effect of –Me (methyl), –OH (hydroxyl), –CHO (formyl) –COOH (carboxyl) and –CN (cyano) substituents. Global reactivity parameters viz. energy of HOMO ( E HOMO ), global hardness ( η ), chemical potential ( μ ) and electrophilicity ( ω ) are computed. Nucleus independent chemical shifts (NICS) values are estimated to study the variation in aromaticity. Time dependent density functional theory (TD-DFT) is used to study the UV–Visible absorption spectra. Effects of BN doping and substituents on corresponding dipole moments and band gaps are also analyzed. Presence of BN unit and/or substituents induced considerable impact on global reactivity, dipole moment, band gap and aromaticity of the chosen systems, especially for BN doped chrysene at the edge. Absorption spectra which are red shifted in presence of BN and substituents are mostly found within the UV-region.

The Sustainable Development Goal (SDG) 3, which was adopted by all United Nations member states in 2015, is ‘Good Health and Wellbeing’. To contribute in the actualization of this goal, the lipid composition of unripe (UR), about to ripe (AR), and ripe (RP) Citrus sinensis fruit pulps were evaluated using standard analytical techniques. The result showed that the same fatty acids and phospholipids were found in all the fruit pulps examined. The most abundant fatty acid in the fruit pulps was palmitoleic acid with concentration (%) of 26.48, 27.82 and 27.14 for UR, AR, and RP samples respectively. This was followed by oleic acid (25.36 %, 29.13 %, 28.66 %), palmitic acid (25.98 %, 20.14 %, 21.66 %), linoleic acid (12.30 %, 11.18 %, 11.33 %), linolenic acid (7.52 %, 8.71 %, 8.19 %), and stearic acid (1.95 %, 2.73 %, 2.72 %) for UR, AR, and RP fruit pulps respectively. The samples contain healthy saturated and unsaturated fatty acid with the concentration of unsaturated fatty acid (71.75 %, 76.92 %, 75.40 %) being prominent in UR, AR, and RP samples respectively. The most prominent phospholipids (mg/100 g) in the fruit pulps was phosphatidylethanolamine with concentrations of 5.86, 6.47, and 6.03 for AR, UR, and RP samples respectively. This was followed by phosphatidylcholine (4.02 mg/100 g, 4.52 mg/100 g, 4.22 mg/100 g), phosphatic acid (3.59 mg/100 g, 4.02 mg/100 g, 3.89 mg/100 g), diphosphatidylglycerol (3.38 mg/100 g, 3.79 mg/100 g, 3.59 mg/100 g), phosphatidylinositol (1.92 mg/100 g, 2.24 mg/100 g, 2.21 mg/100 g), phosphatidylserine (1.86 mg/100 g, 2.08 mg/100 g, 1.91 mg/100 g) and phosphatidylglycerol (1.07 mg/100 g, 1.21 mg/100 g, 1.18 mg/100 g) for UR, AR and RP fruit pulps respectively. The result revealed that Citrus sinensis is a healthy low fat food at every maturation stage and that the fatty acid and phospholipid composition increased as the fruit pulp ripened.