Dopant engineering has become a central strategy for addressing the fundamental shortcomings of pristine semiconductor photocatalysts, such as limited visible-light absorption and rapid charge carrier recombination. This review presents a detailed analysis of recent advances in atomic-scale dopant engineering for modulating the charge separation dynamics to degrade persistent organic pollutants (POPs). Different electronic and structural mechanisms governing transition metal, noble metal, rare-earth element, non-metal and multi-element co-doping strategies are deconstructed. The ways foreign atoms modulate the semiconductor framework are critically evaluated. Bandgap narrowing via orbital hybridization, shallow vs. deep trap-assisted kinetic separation and generation of localized internal electric fields via lattice distortion are the physical pathways discussed. This work also correlates the atomic modifications with macro-scale photocatalytic performance in terms of the degradation pathways for synthetic azo dyes, complex pharmaceuticals and broad-spectrum antibiotics. Finally, this work addresses prevailing industrial bottlenecks such as the over-doping dilemma, structural stability and scalability presenting a definitive roadmap to design the next generation of highly efficient solar driven photocatalysts for global environmental remediation.
A series of nine thiazole-hydrazone hybrids (D1-D9) was prepared in two steps: 5-chloro-1,3-dimethyl-1H-pyrazole-4-carbaldehyde was condensed with thiosemicarbazide, and the resulting thiosemicarbazone was cyclized with substituted phenacyl bromides. The products were characterized by Fourier-transform infrared (FT-IR) spectroscopy, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry. Antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Klebsiella pneumoniae, and antifungal activity against Candida albicans, were screened by the Kirby-Bauer disc diffusion method. Compounds D1, D2 and D7 were the most promising, mainly against the Gram-negative strains and C. albicans. Docking of the most active compounds into four microbial target proteins (Protein Data Bank IDs 4URM, 1KZN, 5ECX and 5TZ1) gave binding energies of -6.7 to -8.7 kcal/mol, with hydrogen-bonding and hydrophobic contacts in the active sites. Density functional theory (DFT) calculations supplied frontier orbital energies, reactivity descriptors and electrostatic potential maps, and in silico absorption, distribution, metabolism and excretion (ADME) screening suggested drug-like behavior. These results point to thiazole-hydrazone hybrids as useful starting points for antimicrobial lead development.
The living systems are, at their core, extraordinarily sophisticated organic chemistry laboratories. Every biological process including DNA replication, enzyme catalysis, signal transduction, metabolism is executed through the same functional-group chemistry taught in an introductory organic course: nucleophiles attacking electrophiles, acids donating protons to bases, electrons flowing through conjugated systems. This review examines how organic chemistry principles explain the structure and behaviour of biomolecules, how biological catalysis mirrors and inspires laboratory reactivity, and how this shared chemical language is exploited across the drug development pipeline right from target identification and hit discovery to lead optimization, pharmacokinetics, and clinical translation. The boundary between "organic chemistry" and "biology" is, in a real sense, artificial. Carbohydrates, lipids, proteins, and nucleic acids are organic molecules governed by the same rules of bonding, stereochemistry, and reactivity as any small molecule on a laboratory bench. What makes biological chemistry distinctive is not a different set of rules but an extraordinary degree of control: enzymes accelerate reactions by many times precisely organizing functional groups in three-dimensional space, and biological systems achieve levels of chemo-, regio-, and stereoselectivity that synthetic chemists still strive to match. Drug development sits directly at this interface. A drug is, definitionally, a small organic molecule (or increasingly, a biologic) designed to intervene in a biological process using organic-chemical logic like binding a receptor through hydrogen bonds and van der Waals contacts, inhibiting an enzyme by mimicking its transition state, or undergoing metabolic transformation that activates or deactivates the compound. This review traces that logic from the fundamental organic chemistry of biomolecules through to its application in modern drug discovery.
The Schiff base ligand (L) N-(4-(diethylamino-2-hydroxybenzylidene)isonicotinohydrazid was synthesized by reaction of isoniazid with 4-(diethylamino)-2-hydroxybenzaldehyde using microwave assisted method and then synthesized its transition metal complexes having general formula [Cr(L)2], [Mn(L)2], [Fe(L)2], [Co(L)2], [Ni((L)2], [Cu((L)2] and [Zn(L)Cl]. 1H NMR,13C NMR, FT-IR and TGA characterized the synthesized Schiff base and its transition metal complexes. Spectroscopic data indicate that the Schiff base ligand (L) is tridentate, featuring an ONO donor atom. The synthesized Schiff base transition metal complex [Zn(L)Cl] demonstrated the highest antidiabetic inhibitory activity with 50% inhibition, whereas the other complexes showed a maximum inhibition of 30%. The synthesized Schiff base and its transition metal complexes do not exhibit fluorescence.
This study examines the effectiveness of low-cost adsorbents derived from agricultural waste in removing Rhodamine 6G from simulated dairy effluent and dye wastewater. The dairy industry generates substantial wastewater with a high organic content, while textile dye wastewater poses challenges due to the presence of persistent and toxic-colored compounds. Adsorption was explored using activated carbon, peanut hull, and banana peel. Synthetic wastewater samples mimicking dairy effluent were prepared, and Rhodamine 6G was added. Batch experiments assessed dye removal efficiency under varying conditions, including adsorbent dosage, initial dye concentration, and the presence of organic matter. Transmittance and absorbance measurements quantified Rhodamine 6G concentrations. Activated carbon showed the highest transmittance of 95.93% when treated with activated carbon at its lowest concentration of 20 mg/L and milk wastewater concentration at 50 mg/L. Peanut hull treated Rhodamine 6G at a concentration of 20 mg/L and milk wastewater at 50 mg/L, achieving a transmittance value of 76.03%. At a dye concentration of 20 mg/L and milk wastewater concentration of 50 mg/L, banana peel powder yielded the highest transmittance value of 84.07%. Organic matter in simulated dairy effluent slightly impacted adsorption, likely due to competitive adsorption. However, agricultural waste adsorbents maintained reasonable performance. Agricultural waste materials show potential as low-cost alternatives to activated carbon for dye-containing wastewater treatment. Converting these wastes into effective adsorbents offers an economical and sustainable solution, contributing to a circular economy. Further research should optimize the process, enhance the adsorption capacity of waste adsorbents, and examine their long-term stability and reusability.
