Background: On account of significant biological activities, quinoline derivatives have drawn more attention to the synthesis and biological activities in the search for new therapeutic agents. Several new synthetic approaches have been implemented to derive new molecules from quinoline and all the synthesized molecules showed effective anticancer activity. Method: Some molecules are synthesized using quinolones as precursor reactant, which is another effective product of quinoline, also showing significant activity against malignant tumors. The presence of nitrogen in it and its ability to bind with enzymes like gyrase, topoisomerase II and kinase have also proven it with antitumor activity. Conclusion: This review encapsulates the recent advances in the synthesis and anticancer activity of Quinoline derivatives.

Continued emergence and spread of multidrug-resistant bacteria behooved the development of alternative treatment strategies, including antimicrobial drugs. A hopeful approach is to target cellto- cell communications, commonly known as quorum-sensing (QS) and microbial biofilm formation. Quorum Sensing is a method used on bacteria to determine their physiological behavior and coordinate gene expression based on the cell to cell signaling. Many physiological functions of bacteria are controlled by quorum sensings such as virulence, motility, sporulation, luminescence, and biofilm formation. Microbial biofilms are organized aggregations of cells attached to a substratum and surrounded by a self-produced extrapolymeric substance (EPS) matrix. Currently, biofilm formation and quorum sensing are considered as a prospective novel target for antimicrobial therapy to control multidrug- resistant infections. Plant-based natural products have been comprehensively studied in this context. In this review, a comprehensive overview of various research papers published in the last decade on plant-derived molecules that are capable of inhibiting quorum sensing or microbial biofilm formation is reviewed, mentioning the biosynthetic classes of active compounds and their biological activity in the performed assays.

Background Tuberculosis (TB) caused by Mycobacterium tuberculosis is one of the main killers of people all over the world. The major hurdles with existing therapy are the lengthy regimen and appearance of multi drug resistant (MDR) and extensively drug resistant (XDR) strains of M.tuberculosis. Aims The present work was aimed to synthesize and determine antitubercular and antimicrobial potential of some novel 3-chloro-4-aryl-1-[4-(5-pyrazin-2-yl[1,3,4]oxadiazole-2-ylmethoxy)-phenyl]-azetidin-2-one derivatives 7(a-h) from pyrazinoic acid as precursor, which is a well-established antitubercular agent. Here we report the synthesis of a new class of heterocyclic molecules in which pyrazine, 1, 3, 4-oxadiazole and azetidinone moieties were present in one frame work. Methods Pyrazinoic acid (1) was esterified first (2) followed by amination to produce hydrazide (3) which was refluxed with POCl3 to obtain 2-chloromethyl-5pyrazino-1, 3, 4-oxadiazole (4). This was then further reacted with 4-amino phenol to obtain 4-[5-pyrazino-1, 3, 4-oxadiazol-2-yl-methoxy]-phenyl amine (5) which on condensation with various aromatic aldehydes afforded a series Schiff’s bases 6(a-h). Dehydrative annulations of 6(a-h) in the presence of chloroacetyl chloride and triethylamine yielded 3-chloro-4-aryl-1-[4-(5-pyrazin-2-yl-[1, 3, 4]oxadiazole-2-ylmethoxy)-phenyl]-azetidin-2-one derivatives 7(a-h). Antibacterial, antifungal and antitubercular potential of all the synthesized compounds were assessed. Docking study was performed using the software VLife Engine tools of Vlifemds 4.6 on the protein lumazine synthase of M. tuberculosis (PDB entry code 2C92). Results The present studies demonstrated that synthesized oxadiazole derivatives have good antimicrobial activity against the various microorganisms. Among the synthesized derivative, 7b and 7g were found to be prominent compounds which have potential antibacterial, antifungal and antitubercular activity (with MIC 3.12 µg/ml and high dock score ranging from −59.0 to −54.0) against Mycobacterium tuberculosis. Conclusions Derivatives 7b and 7g would be effective lead candidates for tuberculosis therapy.

Globally, cancer is considered as the major leading cause in decreasing the patient health care system of human beings. The growing threat from drug-resistant cancers makes heterocyclic moieties as an urgent need to develop more successful candidates for anti-cancer therapy. In view of outstanding pharmacological activities Quinolone and its derivatives have attracted more attention towards drug designing and biological evaluation in the search of new drug molecules. The inspired researchers attempted efforts in order to discover quinolone based analogs due to its wide range of biological activities. Due to immense pharmacological importance, distinct synthetic methods have been executed to attain new drug entities from quinolones and all the reported molecules have shown constructive anticancer activity. Some of the synthetic protocol like, one pot synthesis, post-Ugi-transformation, catalysed based synthesis, enzyme-based synthesis and nano-catalyst based synthetic procedures are also discussed as recent advancement in production of quinolone derivatives. In this review, recent synthetic approaches in the medicinal chemistry of quinolones and potent quinolone derivatives on the basis of structural activity relationship are outlined. Moreover, their major methods and modifications are discussed.

Pyridazinone and its derivatives have various ranges of biological and pharmacological activities including anti-inflammatory, antifeedant, anticonvulsant, antidiabetic, herbicidal, antihypertensive, antiplatelet, antifungal, antibacterial, anticancer and antiviral activities. Pyridazinone magic moiety has allowed the generation of a huge number of structurally different derivatives. Most of the pyridazinone derivatives are derived from substitution of the pyridazinone oxygen, nitrogen and C4/C5/C6 carbon positions. Pyridazinone can be used for the synthesis of a large variety of heterocyclic compounds and as intermediate for a broad spectrum of drug synthesis. Constant use of non-steroidal anti-inflammatory drugs is often accompanied by side effects such as bleeding, nephrotoxicity and gastrointestinal lesions. To minimise these side effects some of the pyridazinone derivatives are synthesised with an improved gastrointestinal tract and renal safety profile linked to other non-steroidal anti-inflammatory drugs. In this review, we have discussed the pyridazinone nucleus which serves as an important therapeutic agent in the field of non-steroidal anti-inflammatory drugs. This nucleus has a wide spectrum in bioorganic and medicinal chemistry and application in drug discovery.

Sumeet Gupta, Satish Burman, Anroop B. Nair, Samrat Chauhan, Debabrata Sircar, Partha Roy, Meenakshi Dhanwat, Debrupa Lahiri, Dinesh Mehta, Rina Das, and Hany Ezzat Khalil. Prev Nutr Food Sci 2022;27:50-62. https://doi.org/10.3746/pnf.2022.27.1.50