Mini-Reviews in Organic Chemistry - Volume 22, Issue 1, 2025

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is one of the deadliest viruses among respiratory viruses which resulted in COVID-19 pandemic. The virus gets transmitted by the nasal route and moves down to the trachea, bronchi, and then to the lungs. Once replicated inside the alveolar cells, the SARS-CoV-2 makes the membrane of the alveolar sac porous, which causes the leaking of plasma from surrounding blood vessels into the alveolar sac leading to its buildup. This process results in the production of pro-inflammatory cytokines like interleukin-1β (IL-1β) and Tumor necrosis factor-α (TNF-α) by the helper T-cells at the site of the infection, causing difficulty in breathing. Plant-based alkaloids can be promising to treat viral infections. Plants have contributed to drug development against viruses like Herpes simplex virus (HSV), Human immunodeficiency virus (HIV), Hepatitis B virus (HBV), and viruses that cause respiratory diseases in humans. Plant alkaloids, either in the form of extract, infusion, or powder, have shown potential in treating viral diseases mainly by targeting the replication of viruses. Alkaloids like Tetrandrine, Oxymatrine, and Berberine have been shown to have a positive role in mediating pro-inflammatory cytokines like IL-1. These alkaloids thus inactivate the nuclear factor kappa-B (NF-kB) pathway, inhibiting the expression of its targeted genes, IL-1β and TNF-α. This inactivation of NF-kB results in reduced levels of IL-1 and TNF-α, and consequently reduced inflammation, decreasing the stress on the immune cells and increasing the ability of the patient to fight the infection. Despite vaccine development for SARS-CoV-2, the virus is continuously evolving into new varieties, posing a threat to humans and it is necessary to develop effective drug discovery programs. Natural products can pave the way in this regard. This review can contribute towards safer drug development against SARS-CoV-2, combating the threat of the ever-emerging variants of this virus.

In-depth research is being carried out on mangrove communities, which are regarded as significant habitats for microorganisms’s, in order to find novel secondary metabolites with useful pharmaceutical and medicinal uses. According to a growing number of articles that point to the enormous potential of this ecological niche, mangrove-associated fungi are acknowledged as a rich source of bioactive chemicals. The fungi Aspergillus sp., Penicillium sp., and Fusarium sp., which are isolated from the plant's leaves, rhizosphere, rhizospheres’ soil, and pneumatophore, are mangrove-associated and derived, according to this review. The secondary metabolites produced by fungi originating from mangroves, including alkaloids and polyketides, are discussed in this research, along with how these fungi are the source of bioactive chemicals with potent bioactivities, including antibacterial, anti-inflammatory, antioxidant, antifungal, and anticancer properties.

Water, a kind of abundant natural resource, is considered to be a green and desirable solvent for reasons of its low cost, high safety and environmental friendliness. This review article aims to briefly introduce the methodologies that have utilized water as reaction media under the aid of granular polytetrafluoroethylene (PTFE) to mediate reactions of a series of water-insoluble and high melting points substrates in a green, quantitative, fast, and stereoselective way in most situations. Besides, this review will be helpful to stimulate further study on both practical applications and mechanistic understanding of these aqueous reactions promoted by granular PTFE for the novel synthesis of interesting structures.

It is known that flotation is the main method of extracting non-ferrous metals. The need of modern society for precious metals is constantly growing, and deposits of easily reversible ores are being depleted. Therefore, the improvement of the reagent regime and the search for new flotation reagents is an urgent task. We analyzed the literature data on the synthesis and use of common collectors such as xanthates and dithiocarbamates. Particular importance is given to recent progress in the functionalization of xanthates and dithiocarbamates, their selective characteristics and flotation mechanisms. Progress in the field of flotation can be made in the use of new effective reagents and their combinations, as well as in the modification of already known collectors. The generalization of the material in this review will help in the development of this area. The mini-review summarizes the syntheses of collectors such as xanthates and dithiocarbamates with the increased selective properties in the flotation process of non-ferrous metals. Furthermore, this review provides an analysis of the developments in these studies, especially highlighting recent progress in the functionalization of xanthates and dithiocarbamates, their selective characteristics and flotation mechanisms.

Cucurbiturils are a class of macrocyclic compounds with highly polar carbonyl portals and a hydrophobic cavity. They are usually utilized as efficient host molecules in supramolecular chemistry applications due to their high binding affinity for positively charged or cationic compounds. This review investigates the application of CB[n] immobilization at semi-conductive interfaces to produce electrochemical sensors. Critical to the production of thin film electrode preparations is the solubility of the CB[n] to produce homogeneous thin films when deposited. The solubility of CB[n] molecules in organic and inorganic solvents is limited; however, CB[7] has been applied successfully in the production of a wide range of electrochemical sensors. Furthermore, we introduce simple drop-casting of efficiently solubilized CB[7] as a simple yet effective method for producing CB[7] modified electrochemical sensors for the sensitive reporting of dopamine in aqueous solutions in the concentration range of 3.33×10^-9 to 1.16×10^-8 M with a sensitivity of 0.315 µA/M, (n=3).

Heterocyclic moiety is a key part of some enzymes and vitamins and plays a vital role in various biochemical and enzymatic processes. Piperazine ring is a heterocyclic moiety present in various well-known drugs and is effective against different types of diseases by acting on a variety of receptors. Various piperazine analogs possess diverse biological activities, especially in central nervous system disorders, which involve the activation of neurotransmitter receptors and targeting various enzymes and act as antianxiety, antipsychotic, antidepressant, etc. This review is focused on the piperazine derivatives and their diverse therapeutic potential against different types of diseases particularly against neuronal disorders.

Catalytic transformations have been observed in every reaction to provide a specific product and to formulate regio and stereo-selective adducts in well-defined pathways. Among various catalytic processes used in current chemistry, tandem catalysis has been proven to be an effective technology by applying the technology for better and time-saving ways of production. It has shown its usability in various fields of research like organic reactions, inorganic salt extractions, isolation, and purification of intermediates, photoprotection of dye, pigment, and polymer chemistry, specifically in paint industries, biological sequencing and natural product chemistry. Ideally, it is a single molecule conversation to the desired product (beneficial to both research and industries) with many competing effects in spatial arrangement with almost no major equipment in operation. The advantages of tandem catalysis in the field of chemistry (Organic/Bio-chemistry/Polymer chemistry etc.) by utilizing the positive side is a newer way for energetic and favourable technology.

Cyclodepsipeptides, mainly derived from marine organisms and soil microorganisms, are amphiphilic molecules consisting of short oligopeptides with fatty acid tails attached to form a macrocyclic structure. Studies on the activity of cyclodepsipeptides have shown that they have cytotoxicity, antibacterial and anthelmintic effects, and are widely used in biological control, drug development, environmental remediation and disease treatment. Cyclodepsipeptides play a prominent role in the development of new drugs and drug lead compounds, especially as antibiotics with great medicinal potentiall, and are slowly seeping into the public consciousness. The biosynthesis of cyclodepsipeptides is mainly based on the synthesis of non-ribosomal peptide synthases, and selection of key regulatory enzymes for homologue regulation and biosynthetic strategies using genetic engineering and metabolic engineering approaches. The biosynthesis method is miniaturised, recyclable, and safer. The total synthesis methods of cyclodepsipeptides are mainly combined solid-liquid phase methods, which synthesise cyclodepsipeptides faster and are easy to purify. This paper reviews the biological activities of cyclodepsipeptides, their biosynthesis, and total synthesis.