Current Organic Chemistry - Volume 27, Issue 20, 2023

Heterocyclic compounds are currently of great interest in pharmaceutical research. Many natural products, including vitamins, hormones, and antibiotics, contain heterocyclic compounds, and these substances have grown in importance. Heterocyclic thiazine derivatives have numerous pharmacological actions, including anticancer, antimicrobial, antipsychotic, anti-mycobacterial, anti-fungal, antiviral, antimycobacterial, antioxidant, analgesic, antipyretic, anti-inflammatory activities, which is present in numerous substances. The N-CS linkage in its scaffold and the ease and economy of its synthesis methods have been key factors in the development of these molecules. Recently, numerous studies considering the various biological actions of thiazines have been published. Thiazine, a six-membered heterocyclic compound with nitrogen and sulfur in its ring system, has a wide range of chemical possibilities, which has encouraged insistent research into their various synthesis processes. The current review focuses on thiazine derivatives with potential biological activities.

Multi-component reactions have been used as an important synthetic strategy for the synthesis of diverse varieties of therapeutically useful heterocyclic scaffolds. High atom economy, one-pot reaction, and involvement of synthetically simple steps are some of the interesting features that make MCRs greener compared to conventional methods. The development of environmentally benign and eco-friendly synthetic methods has been a very demanding area of research in the past few decades. In particular, the development of energyefficient methods has attracted the attention of the research community due to heavy dependence on non-renewable energy resources, which is depleting fast. Therefore, the present review has highlighted the multi-component reactions developed under the energy efficient protocol, which mainly include the reactions developed under the microwave, ultra-sonication, mechanochemical, and photochemical reaction conditions for the synthesis of therapeutically relevant heterocycles.

In many significant bioactive heterocyclic compounds, the six-membered ring pyrimidines play a major role as bioactive components. There is a lot of room for innovation in the fields of medicinal chemistry and the chemical industries because of the numerous pyrimidine synthesis methods and their varied reactions. The pharmacological effects of pyrimidine derivatives include anticonvulsant, antibacterial, antifungal, antiviral, antitubercular, anticancer, antimicrobial, antihypertensive, antiulcer, anti-inflammatory, antimalarial, antioxidant, analgesic, sedative, anti-depressive, antipyretic properties, etc. The synthetic adaptability of pyrimidine has made it possible to create a wide range of structurally different analogs, including analogs from substitution on the pyrimidine ring at various places, which has aided the design of a wide variety of therapeutic targets. This review's goal is to examine the pharmacological effects of numerous pyrimidine derivatives. This review provides an overview of pyrimidine compounds for biological activities and examines the novel pharmacological molecules containing pyrimidine rings in the future.

Schiff bases are dynamic organic compounds of bioactive importance, acting as flexible ligands and can form complexes with metals. Schiff bases along with their metal complexes have shown a large affinity towards DNA, which is one of the main targets of chemotherapeutics. DNA can join hands with these motifs in multiple ways, like covalent (crosslinking adducts) and non-covalent (intercalative or groove binding via electrostatic) interactions. Besides, the binding ability and types vary with the metals involved in Schiff base metal complexes. Thus, this review aims to describe significant recent reports of Schiff bases and their metal complexes capable of binding with DNA to evaluate the superlative DNA binders, type of association, and best metal-Schiff base combinations. Among the experimental techniques employed in revealing these interactions, noteworthy UV absorption and fluorescence spectroscopy studies have been discussed for the assessment of various types of bindings as intercalation or groove type.

Optically pure alcohols have a pivotal synthetic role, being key intermediates for numerous pharmaceutical agents. Therefore, the synthesis of optically pure alcohols is now becoming a foremost research field in both academia and industries. Herein, Bacillus thuringiensis has been described for the first time for the bioreduction of acetophenone to 1-phenylethanol. Five incubated bacillus species and a consortium were investigated for the reduction of acetophenone. Among them, Bacillus thuringiensis (growing cells) exhibited >99% conversion efficiency of acetophenone (40 mM). The biocatalyst produced (R)-1-phenyl ethanol with excellent stereoselection (99%) at pH 7.5 after 24 h reaction intervals. To enhance the solubility of substrate and cofactor regeneration, isopropanol (10% v/v) was found to be effective among different tested cosolvents. The biocatalyst displayed excellent stereoselectivity and provided R-enantiomer with 99% enantiomeric excess.

Amylase, lipase, and trypsin are crucial digestive enzymes, whose activation or inhibition is of potent therapeutic approach for treating various body disorders. In this work, we have synthesized a small library of pyrrolidine-tethered novel aurones 4(a-k) and structures validated by analyzing their IR, NMR (¹H and ¹³C), and mass spectrometry data. The biological activities of the synthesized aurones were evaluated through in vitro and in silico experiments against digestive enzymes. A distinct pattern emerged, with significant activation observed for trypsin and amylase, while lipase was notably inhibited. Among the synthesized compounds, 4f produced the highest lipase inhibition (72.3%), whereas 4k showed maximum activation for trypsin (EC50 = 0.940^-6 M) and 4f activated amylase (EC50 = 8.760^-4 M) to the maximum extent, thus confirming their possible use as agents for combating inflammation and obesity.