Enzyme-catalyzed synthesis of bioactive heterocycles

Enzymes are proteins that functions as biological catalyst. It is now a known fact that enzyme can catalyze many synthetic operations better than the conventional reagents. Not only in the synthesis of natural products, they can also be applied for construction of varieties of unnatural compounds. In this chapter, Pariyar and Ghosh have discussed in brief synthesis of various biologically active heterocyclic compounds using different enzymes as catalysts. Among various enzymes, laccases, trypsin, α-amylase and Bakers’ yeast are few that are easily available and have been extensively explored for various synthetic strategies. This chapter will definitely serve as valuable source of information to the readers in the field of enzyme-catalyzed reactions.

Recent Advancements in the Synthesis and Chemistry of Benzo-fused Nitrogen- and Oxygen-based Bioactive Heterocycles

: Since a variety of benzo-fused nitrogen- and oxygen-based bioactive heterocyclic moieties are present in the form of benzoxazinones, spirooxindole-based heterocyclic compounds, coumarin-fused heterocyclic compounds and 2H-indazoles. This review article briefly describes some of the significant advancements and developments in the area of 1,4-benzoxazine-3-ones, 1,4-benzoxazin-2-ones, spiropyrrolidine and spiropyrrolizine-based ring compounds, coumarin-fused compounds, benzopyran-fused coumarins, and a 2H-indazoles class of bioheterocycles. Thus, keeping in view the medicinal importance of these bioactive benzo-fused heterocycles, particular attention has been given to their synthesis and medicinal/pharmaceutical properties in detail.

Efficient and Facile Synthesis of Chromenopyrano[2,3-b] pyridine Derivatives Catalyzed by Sodium Carbonate

In this research, a number of new and known chromenopyrano[2,3-b]pyridine derivatives have been prepared. Initially, according to the reported procedure, pyrano[2,3-c]chromene derivatives were synthesized by the reaction between 4-hydroxycoumarin, aromatic aldehydes and malononitrile using silica sodium carbonate (SSC) as the catalyst. Next, the prepared pyrano[2,3-c]chromenes were reacted by dimethyl acetylenedicarboxylate (DMAD) or cyclohexanone in the presence of sodium carbonate to produce chromenopyrano[2,3-b]pyridine derivatives. The presented protocol avoids the use of expensive catalysts and gives useful potentially bioactive heterocycles in excellent to high yields.

Overview of the Biological Activities of Pyrimido[4,5-d]pyrimidines

: Over the years, the development of bioactive heterocycles has aroused the interest of the scientific community, because in general, these heterocycles are strategic in maintaining life. Research into bioactive heterocycles is associated with the development of methods of synthesis and the biological evaluation of different nuclei. In consequence, there has been a growing interest in the nucleus of fused pyrimidine, which has diversified pharmacological activities, including diuretic, antimicrobial, antifolate, tyrosine kinase, anti-inflammatory, anticancer, anthelminthic, and antiviral activities. This review focuses on describing a diverse set of structures derived from pyrimido[4,5-d]pyrimidines and contemplates the main bioactivities of these nuclei.

Recent Advances in the Development of 1,2,3-Triazole-Containing Deriva-tives as Potential Antifungal Agents Inhibitors of Lanosterol 14α-Demethyl-ase

Abstract:: 1,2,3-Triazole, a five-membered heterocyclic nucleus, is widely recognized as a key chromophore of great value in medicinal chemistry for delivering compounds possessing innumerable biological potentials encompassing antimicrobial, antitubercular, antidiabetic, antiviral, antitumor, antioxidants and anti-inflammatory. Particularly, in the past years, diverse conjugates carrying this biologically valuable core were reported owing to their attracting fungicidal potentials and their potent actions on diverse infective targets. Hence, hybridization of 1,2,3-triazole with other antimicrobial pharmacophores appears to be a judicious strategy to develop new efficacious anti-fungal candidates aiming at combating the emergence of drug-sensitive and drug-resistant infection disease. Thus, the current review highlights the recent advances of this promising category of 1,2,3-triazole-containing hybrids incorporating diverse varieties of bioactive heterocycles such as conozole, coumarin, imidazole, benzimidazole, pyrazole, indole, oxindole, chromene, pyrane, quinazoline, chalcone, isoflavone, car-bohydrates, amides. It underlies their inhibition behavior against different panels of infectious fungal species for the period during 2015-2020.

p-Sulfonic acid calix[n]arene catalyzed synthesis of bioactive heterocycles: A review

: Metal-free organocatalysts are becoming an important tool for the sustainable developments of various bioactive heterocycles. On the other hand, during last two decades, calix[n]arenes have been gaining considerable attention due to their wide range of applicability in the field of supramolecular chemistry. Recently, sulfonic acid functionalized calix[n] arenes are being employed as an efficient alternative catalyst for the synthesis of various bioactive scaffolds. In this review we have summarized the catalytic efficiency of p-sulfonic acid calix[n]arenes for the synthesis of diverse biologically promising scaffolds under various reaction conditions. There is no such review available in the literature showing the catalytic applicability of p-sulfonic acid calix[n]arenes. Therefore, we strongly believe that this review will surely attract those researchers who are interested about this fascinating organocatalyst.