Advanced Journal of Chemistry, Section A
Volume:7 Issue: 1, Winter 2024

Dolichos pachyrhizus (Annonaceae) has been traditionally used in Africa to treat syphilis and many other microbial infections. However, no phytochemical study and antimicrobial investigations have been conducted on this species. Thus there is need for the discovery and development of new antibiotics and anifungal. The triterpenoids [Lupeol (1) and β-amyrin (2)] isolated from rhizome of Dolichos pachyrhizus (Harm) were evaluated for their antimicrobial activity against some selected Gram positive bacterial, Gram negative bacterial and Fungal isolates. The antimicrobial activity of the crude extract and compounds isolated was determined using agar well diffusion method. The compounds exhibited antimicrobial activity against most of the tested bacteria with minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentrations (MBC/MFC) values ranging from 2.5 to 20 mg/ml and 5 to 40 mg/ml, respectively. The triterpenoids could be a potentially effective antimicrobial agent to combat infectious diseases. The structures of the compounds were elucidated using modern spectroscopic and spectrometric techniques such as nuclear magnetic resonance (NMR) and mass spectrometry (MS) to be Lupeol and β-amyrin.

Methicillin-resistant Staphylococcus aureus (MRSA) poses an increasingly alarming threat to global public health, characterized by its escalating antibiotic resistance and heightened virulence. This dire situation necessitates the exploration of novel and hitherto uncharted targets for effective pathogen control. The primary objective of our current investigation is to identify the most promising riboswitch as a druggable target and assess its potential inhibition through both small molecules and antisense oligonucleotides (ASO) in silico. I conducted an exhaustive search for the most plausible druggable riboswitch using the RiboScan tool, subsequently subjecting its sequence to rigorous docking studies with ten distinct resveratrol derivatives through the PatchDock algorithm. In addition, we harnessed the power of ASO by designing and hybridizing five ASO sequences to silence the identified riboswitch target effectively. This comprehensive analysis pinpointed the glmS riboswitch as the most promising candidate for targeted intervention. Molecular docking results uncovered the exceptional inhibitory potential of resveratrol derivatives, with particular emphasis on ZINC000100827960, which emerged as a lead natural inhibitor. Furthermore, the ASO sequences, meticulously designed for their intended purpose, exhibited compelling efficacy in terms of hybrid free energy, RNA-RNA docking interactions, and a remarkably low probability of causing off-target effects within the human transcriptome. Taken together, our findings underscore the significant promise of both resveratrol derivatives and the ASO candidates as potent inhibitors of the glmS riboswitch in MRSA. These results warrant not only further consideration, but also rigorous experimental validation to pave the way for innovative strategies in combating the menace posed by MRSA.

The primary hindrance to widespread solar energy adoption has been the high initial cost of technology. Traditional silicon solar cells, while efficient, are costly. Perovskite solar cells face three key challenges: instability under various conditions, environmental toxicity from synthetic additives and solvents, and long-term reliability concerns. To address this, we are exploring perovskite solar cells (PSCs) for their potential cost-effectiveness by enhancing PSC performance and stability using natural dyes extracted from cashew and mango leaves, offering an eco-friendly solution to toxic additives. UV spectrophotometry was used to compare the optical properties of perovskite devices with and without plant dyes, and the results showed enhanced optical properties with plant dyes. The band gaps of the pristine device and those incorporating cashew dye and mango dye were measured at 1.59 eV, 1.70 eV, and 2.52 eV, respectively. The samples that were prepared were confirmed to be polycrystalline in nature through XRD analysis. The SEM analysis offered valuable insights into the morphological characteristics of the perovskite films before and after dye treatment, each sample exhibiting unique attributes. Also, EDX elemental analysis proved that the substrate contained CH3NH3PbI3. The perovskite solar cell with mango dye had a PCE of 0.0297% and an improved FF of 0.571, indicating the potential impact of cashew dye. After 1032 hours the optical properties of the samples were monitored under room temperature and conditions to assess their stability.

Due to continuous growing in energy consumption brought on by economic development and population growth around the world, solar energy has emerged as one of the most important sources of renewable energy for human use. In this study, twelve metal-free organic dyes containing 2-[3-(10H-phenothiazin-3-yl)furan-2-yl]-10H-phenothiazine and its analogues as donor units inform of the D-A-π-A structure (PBPD and PTPD) were theoretically studied for application in dye-sensitized solar cells (DSSCs). The structural, electrical, photovoltaic and optical properties of the PBPD and PTDP dyes were carefully examined in relation to the impacts of changing the donor and π-spacer. The PBDP dyes showed band gaps (ΔEg) in the range of 1.75 (PBPD-4) to 2.09 eV (PBPD-3) while ΔEg values for PTPD dyes range from 1.87 eV (PTPD-4) to 2.33 eV (PTPD-3). The estimated open-circuit voltage (Voc) values ranged from 0.79 eV (PTPD-3) to 0.96 eV (PBPD-1 and PBPD-2) while the light gathering efficiency (LHE) values ranged from 0.766 (PTPD-2) to 0.968 (PBPD-6). The HOMO energies, ΔEg values, injection drive force (ΔGinj), reorganization energies (λ total) and coupling constant (|V_RP |) favoured PBPD dyes over PTPD dyes.

Substantial hazards are posed by cadmium (Cd), a hazardous heavy metal, to both human well-being and the ecosystem. To address this, the environmentally friendly and cost-effective technique of biosorption is employed, utilizing biological materials. In our research, emphasis was placed on the development of a biosorbent material using readily available agricultural waste, olive stones powder (OSP). The effectiveness of OSP in the extraction of Cd(II) ions from diverse aqueous solutions under various experimental parameters was evaluated. Additionally, the adsorption kinetics and isotherms were analyzed using different models. The findings revealed a strong adsorption capacity and affinity of OSP for Cd(II) ions, with a maximum value of 20.245 mg/g achieved at pH 6, an OSP dosage of 0.05 g, and a contact time of 30 minutes. The adsorption process followed the pseudo-second-order kinetic model and conformed to the Freundlich isotherm model. Furthermore, comparison of the maximum capacity value (Qm) of OSP obtained in our study with previous research showed it to fall within the intermediate range. Overall, our study demonstrated the potential of OSP as a highly effective biosorbent material for the efficient elimination of Cd(II) ions from aqueous solutions.

Water hyacinth, an abundant aqueous source of biomass, can be considered as a cash crop if properly utilized. As a lignocellulosic biomass, water hyacinth consists of three major chemical components-cellulose, hemicellulose, and lignin. These components have their direct industrial applications and can be used as raw materials to synthesize numerous chemicals. The objective of this study was to co-extract the cellulose, hemicellulose, and lignin from water hyacinth. Hemicellulose and lignin were isolated from water hyacinth by acidic and basic treatment, respectively. The operating conditions (concentration, temperature, and time) of the acid and basic treatment processes were optimized based on the hemicellulose and lignin yield. The solid residue was further oxidized by a bleaching process to obtain cellulose. The yields for cellulose, hemicellulose, and lignin-rich solids were determined as 20.5%, 7.9%, and 13.8%, respectively. The products were confirmed and characterized by FTIR and XRD. Highly crystalline nanocellulose particles were produced. From XRD, the crystallinity index and average crystallite size were calculated as 61- 67.59% and 4.26 nm, respectively.

In recent years, considering the global warming and climate changes mainly resulting from greenhouse gas emissions, especially carbon dioxide, absorption and storage of carbon dioxide in generating clean and sustainable fuels such as hydrogen fuel production have been heavily studied and investigated. Researchers have presented various methods for carbon dioxide absorption in the hydrogen production process. The biomass gasification process, alongside absorption, can enhance the generation of hydrogen-rich gas by absorbing carbon dioxide. In this study, the first hydrogen generation in the biomass gasification process has been examined, followed by the technologies available for the absorption of carbon dioxide. This study reveals that developing novel materials for absorbing and separating carbon dioxide is essential. Given their unique physicochemical and structural features, metal-organic frameworks, including pore size, high thermal stability, high absorption capacity, and pore size tuning, are helpful adsorbents for absorbing carbon dioxide and achieving clean hydrogen energy. Thus, metal-organic frameworks (MOFs) may efficiently generate high-purity hydrogen by merging biomass gasification with CO2 adsorption.