In the past decade, a sudden increase in the number and kind of emerging water contaminants has been observed. The emerging contaminants can be categorized as organic or inorganic. Organic contaminants have been known for years, and techniques for their detection and remediation have been developed. However, inorganic pollutants are much more common. This is because they are detected in very low or negligible concentrations and are equally toxic as organic pollutants at higher concentrations. To boost the research on inorganic pollutant contamination, advancements in detection and quantification techniques are required. The presented paper discusses major inorganic pollutants such as metals and their salts, inorganic fertilizers, sulfides, acids and bases, and ammonia and oxides of nitrogen. In addition, it discusses the inorganic toxicants’ toxicity to organisms and the environment, upgraded quantification methods, and advancements in inorganic toxicant mitigation. Moreover, the major bottlenecks in the quantification and removal of inorganic pollutants are discussed at the end.

Triazine, one of the nitrogen containing heterocyclic compounds has attracted the considerable interest of researchers due to the vast array of biological properties such as anti-viral, antitumor, anti-convulsant, analgesic, antioxidant, anti-depressant, herbicidal, insecticidal, fungicidal, antibacterial and anti-inflammatory activities offered by it. Various antibacterial agents have been synthesized by researchers to curb bacterial diseases but due to rapid development in drug resistance, tolerance and side effects, there had always been a need for the synthesis of a new class of antibacterial agents that would exhibit improved pharmacological action. Therefore, this review mainly focuses on the various methods for the synthesis of triazine derivatives and their antibacterial activity.

Heterocyclic chemistry is the only branch of chemistry that has applications in varied areas such as dyes, photosensitizers, coordination compounds, polymeric materials, biological, and many other fields. Quinoline and its derivatives have always engrossed both synthetic chemists and biologists because of their diverse chemical and pharmacological properties as these ring systems can be easily found in various natural products, especially in alkaloids. Among alkaloids, quinoline derivatives i.e. quinolinium salts have attracted much attention nowadays owing to their diverse biological profile such as antimicrobial, antitumor, antifungal, hypotensive, anti-HIV, analgesics and anti-inflammatory, etc. Quinoline and its analogs have recently been examined for their modes of function in the inhibition of tyrosine kinases, proteasome, tubulin polymerization, topoisomerase, and DNA repair. These observations have been guiding scientists for the expansion of new quinoline derivatives with improved and varied biological activities. Quinolinium salts have immense possibilities and scope to investigate these compounds as potential drug candidates. Therefore, we shall present a concise compilation of this work to aid in present knowledge and to help researchers explore an interesting quinoline class having medicinal potential.

Various types of isatin derivatives were synthesized by reacting isatin with different reagents viz substituted acetophenones, sodium nitrate, hydroxylamine hydrochloride and hydrazine hydrate. Characterization of the synthesized compounds was done by using various spectral techniques such as IR, 1HNMR, 13CNMR, elemental analysis and mass spectrometry. Synthesized compounds were further evaluated for their antifungal activity against Helminthosporium oryzae, Rhizoctonia solani and Fusarium moniliforme using poison food technique. 3-(2-Oxo-2-phenylethylidene) indolin- 2-one showed significant mycelium inhibition against all tested rice fungi.

Pyrazole derivatives were synthesized by bromination of pyrazole, followed by N-alkylation of 4-bromopyrazole. The synthesized derivatives were characterized by microanalytical data and IR and ¹H and ¹³C NMR spectra and were evaluated for their nematicidal activity against the root knot nematode Meloidogyne incognita. The compounds were screened for their egg hatch inhibition and mortality potential, and they showed significant nematicidal activity as compared to the control. 1H-Pyrazol-5(4H)-one was found to be most effective in egg hatch inhibition, and 4-bromopyrazole was found to be most effective in juvenile mortality.