Chemistry and Biochemistry: Research Progress Vol. 7

Evaluation of DNA Binding and Cytotoxicity of Newly Synthesised Schiff Base (Z)-4-(((2-hydroxy phenyl)amino) (phenyl)methylene)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one and Its Analogues

2025-07-05T12:25:01+00:00

A new Schiff base (Z)-4-(((2-hydroxy phenyl)amino)(phenyl)methylene)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one and its analogues were synthesised by condensation of 5-methyl-2-phenyl-4-substituted pyrazolin-3-one with 2-amino phenol from hot ethanolic solution. Schiff bases appear to be an important intermediate in a number of enzymatic reactions involving the interaction of the amino group of an enzyme, usually that of a lysine residue, with a carbonyl group of the substrate. In this study, the primary Schiff base and its derivatives are characterised by FTIR, UV, H¹NMR, elemental analysis and single-crystal X- ray diffraction analysis. These potential Schiff bases are subjected to DNA binding analysis against the Calf thymus DNA, and their binding constant values were calculated and compared to the standard ruthenium intercalators. The cytotoxic nature of these Schiff bases was also studied against the human breast cancer cell line MCF-7, and their IC₅₀values were determined. The Schiff bases synthesised (L1, L2, L3) were stable at room temperature and possessed good keeping qualities. They were soluble in chloroform, dichloromethane, ethyl acetate and insoluble in n-hexane, petroleum ether, and toluene. The compounds exhibited different tautomeric forms (Gowri et al., 2015) in the solid state: L1 as keto-imine, L2 as imine-ol, and L3 as keto-amine. From ¹H NMR spectra, it was inferred that the resulting Schiff bases exist as a mixture of tautomers (II) and (III) in CDCl₃solution. Electronic spectra revealed four types of transitions, and DNA titration studies showed increasing band intensity at ~230 and ~260 nm with DNA concentration. This study contributes to a better understanding of the interaction mechanisms between Schiff bases and nucleic acids and may aid in the development of potential probes for analysing DNA structure and conformation.

Anti-oxidant Activity of Fruits: The Biological Aspect

2025-07-05T12:30:05+00:00

Fruits and fruit products are an essential part of the human diet. Fruits play an important role in maintaining a healthy diet due to the content of antioxidant compounds such as vitamins (ascorbic acid and tocopherols), minerals (selenium), polyphenols (flavonoids and anthocyanins) and other components such as fibre (pectins and cellulose). This study aimed to evaluate the antioxidant potential of selected fruits. For this study, fifteen types of fresh fruits were collected from the local market in the months of July-September. Three samples of each fruit from different markets were collected. This study evaluated the total phenolic content and antioxidant activities of the collected fruits. The fruit samples were analysed using several in vitro antioxidant assays, including total phenolic content, reducing power assay, free radical scavenging activity, hydroxyl radical scavenging ability, and inhibition of DNA damage. The fruits were extracted with 70% Acetone, which extracts maximum free and conjugated phenolic compounds, including anthocyanins and showed a significant antioxidant activity. The Total Phenolic Content of fruits varied from 40 - 882 mg of gallic acid equivalents per 100g of fresh weight, and more than 60% of fruits showed reasonably high phenolic content. The Phenolic Content of plant foods are known to be a powerful antioxidant; therefore Phenolic content of fruit indicates a rough estimate of antioxidants. The fruit with high Phenolic Content also showed high antioxidant activities. The Hydroxyl radical is an extremely reactive species formed in biological systems, implicated as highly damaging in free radical pathology, capable of damaging almost every molecule found in living cells. Therefore, the Hydroxyl radical Scavenging Activity was assessed by fruit extracts, which showed 60 - 80% Inhibition of Hydroxyl radical in vitro. In addition effect of fruit extracts were assessed for the inhibitory effect of DNA Oxidation invitro and the results showed a decrease in DNA damage. These findings suggest that increased consumption of fruits rich in phytochemicals may help prevent chronic diseases.

Biodiesel Production from Rapeseed Oil

2025-07-05T12:33:04+00:00

Rapeseed oil technology refers to the process of extracting and refining oil from rapeseed, a plant belonging to the Brassicaceae family. It is cultivated in many parts of the world due to its high content of vegetable oils. Rapeseed oil is valued for its nutritional profile, containing a high amount of unsaturated fatty acids, especially omega-3 and omega-6. These are the main steps in the technology of obtaining rapeseed oil: harvesting and preparation, washing and drying rapeseed, grinding or crushing the seeds, pressing the oil (cold or hot pressing), solvent extraction (optional), refining the oil and packaging and storage. Rapeseed oil technology is a well-established process which allows for the production of a versatile and healthy product, used not only in food but also in various industrial and cosmetic applications.

Synthesis and Characterisation of 2-Acetylbenzothiophene-Based Semicarbazone Ligands

2025-07-05T12:35:09+00:00

Two semicarbazone ligands, 2-acetylbenzothiophene-3-semicarbazone (Hbtsc) and 2-acetylbenzothiophene-4-phenyl-3-semicarbazone (Hbtpsc), were synthesised via condensation reactions of semicarbazide derivatives with 2-acetylbenzothiophene. The 2-acetylbenzothiophene scaffold was chosen because of its heteroaromatic core, which is rich in electrons and is known to improve conjugation and bioactivity. Because of their biological significance and adaptable coordination behaviour, semicarbazones are the subject of extensive research. FT-IR, UV-Vis, ¹H and ¹³C NMR spectroscopy, elemental analysis, and single crystal X-ray diffraction (for b) were all used to completely characterise the ligands. Spectroscopic data confirmed the keto tautomeric form of both ligands in the solid state. IR spectra showed characteristic ν(C=N) and ν(C=O) stretching vibrations around the range of 1587-1536 cm⁻¹ and 1753-1682 cm⁻¹, respectively. Signals at δ around 10 ppm and 6–8 ppm in the ¹H NMR spectra were attributed to N–H and aromatic protons, which is in line with the keto tautomer. Electronic spectra displayed broad absorptions at 315–318 nm due to n→π* transitions. Single crystal structural analysis of b revealed a triclinic unit cell with P1 space group and two independent molecules (Z′ = 2) in the asymmetric unit. The molecules adopt an E-configuration across the C=N bond, and C=O bond lengths of 1.235 and 1.221 Å, confirming the presence of the keto form. The structure was stabilised by intramolecular hydrogen bonding and weak C–H···π interactions, which contribute to the formation of a stable zigzag packing arrangement. These structural insights provide a foundation for potential future applications in coordination chemistry and materials science.

Chitosan-stabilized ZnO Nanoparticles: Synthesis, Characterization, and Antibacterial Applications in Wastewater Treatment

2025-07-05T12:38:00+00:00

Zinc oxide nanoparticles (ZnO NPs) are widely recognised for their strong antibacterial properties, making them highly valuable in environmental and biomedical applications. Their appeal lies in their affordability, non-toxic nature, and environmental friendliness. Thanks to their high chemical stability and low toxicity, ZnO nanoparticles are frequently used in disinfectants and in the removal of pollutants from water.

One promising strategy for enhancing the utility of these nanoparticles involves combining them with natural polymers. Among these, chitosan—a biodegradable, biocompatible, and hydrophilic polymer derived from chitin—stands out for its own intrinsic antibacterial properties. When metal-based nanoparticles like ZnO are embedded in chitosan, the resulting nanocomposites benefit from both the antimicrobial strength of the metal and the stability and safety of the polymer.

This chapter presents a green synthesis approach where zinc oxide nanoparticles are stabilised within a chitosan matrix using an alkaline solidification process. The resulting chitosan–ZnO nanocomposite offers multiple advantages, including improved dispersion (non-aggregated nature), recyclability, and enhanced antibacterial action. Such materials hold great promise for diverse applications, particularly in water purification, bacterial control, and prevention of biofouling.

Mechanism of Oxidative Process Inhibition by Roundup: Role of N-phosphomethylglycine and its Photodecomposition Products

2025-07-15T10:29:17+00:00

The presented material presents the results of studies performed on N-(phosphonomethyl)glycine (NPMG). This compound is the active ingredient of the most widely used herbicide in agricultural practice, Roundup (Glyphosate; Tornado; and many others). The presented study investigates the behaviour and toxicological impact of NPMG, the active ingredient in widely used herbicides such as Roundup, Glyphosate, and Tornado. To assess the hazard of photochemical decomposition products formed under the influence of solar ultraviolet radiation and ozone, NPMG was exposed to hard UV radiation with λ = 250-600 nm with simultaneous bubbling with ozone. After 14.3 hours, NPMG is practically not identified in the solution. The decomposition process is complex and multistage. The toxicological effect of aqueous solutions of NPMG and the products of its photochemical decomposition was studied on test objects: luminous bacteria of the Ecolum series and ciliates Tetrahymena pyriformis. Treatment of NPMG with UV irradiation + ozonation leads to a 10-fold decrease in toxicity. Using lux-biosensors based on Escherichia coli, the ability of NPMG photochemical decomposition products to induce oxidative stress in bacterial cells was studied. A comparative study of genetic effects using two genetic bacterial test systems showed that among the products of NPMG photochemical decomposition, there are substances with weak mutagenic and genotoxic activity. It was shown that NPMG inhibits the activity of horseradish root peroxidase by a competitive type: Ki = 0.1004 mM; Km = 1.776 mM; I₅₀ = 0.302 mM. The obtained data show that NPMG is able to block the antioxidant system and can cause the accumulation of free radicals in warm-blooded organisms, which is an addition to the available literature data on the biological targets of the Roundup herbicide.

Microwave-Assisted Synthesis: Characterization and in vitro Biological Screening Effects of Schiff Base Metal Complexes

2025-07-28T07:20:50+00:00

Eco-friendly synthesis and green applications are continuously being explored by researchers all over the world. Numerous research studies demonstrated that microwave technology is a sophisticated tool for both synthesis and leading applications of Schiff base compounds. The greener approach is prioritized over the conventional synthesis because of its environment friendly, less energy-consuming, less time-consuming, and less hazardous compounds synthesis with low cost. Microwave-assisted synthesis is a branch of green chemistry. Microwave irradiated reactions offer reduced pollution, low cost, and high yield, together with simplicity in processing and handling. Some new Schiff bases and their Co(II), Ni(II) and Cu(II) complexes formed by the condensation of salicylaldehyde with 2-amino-4-hydroxy-6-methylpyrimidine (SAP) and 2-chloroacetophenone with 2-chloro-4-nitroaniline (CCA) have been synthesized by conventional as well as microwave methods. All the reagents used for the preparation of the Schiff bases were obtained from Sigma Aldrich. Metal salts were purchased from Loba Chemie. The synthesized compounds were spectrochemically characterized by elemental analysis, molar conductance, FT-IR, UV–Vis, Mass spectral analysis, ESR and Powdered-XRD. The complexes are coloured and stable in air. Analytical data revealed that all the complexes exhibited 1:2 (metal:ligand) ratio with 4 or 6 coordination around the metal center. FAB-mass and thermal data show a degradation pattern of the complexes. XRD patterns indicate a crystalline nature for the complexes. The Schiff base and metal complexes show a good activity against the bacteria; E. coli, S. aureus, S. fecalis and fungi A.niger, T. polysporum, C. albicans. The antimicrobial results also indicate that the metal complexes are better antimicrobial agents as compared to the Schiff bases. These observations show that the majority of the complexes are more active than their respective Schiff base ligand. The higher inhibition zone of metal complexes than that of the ligands can be explained on the basis of Overtone’s concept and the Chelation theory. The findings of the bactericidal and fungicidal investigation of the compounds against the opportunistic pathogens reveal that the synthesized compounds have antipathogenic activity.