Design and synthesis of some novel 3-[5-(4-substituted) phenyl-1,3,4-oxadiazole-2yl]-2-phenylquinazoline-4(3H)-ones as possible anticonvulsant agent

Quinazolinone-Peptido-Nitrophenyl-Derivatives as Potential Inhibitors of SARS-CoV-2 Main Protease

The severe acute respiratory syndrome coronavirus 2 main protease (SARS-CoV-2-M^pro) plays an essential role in viral replication, transcription, maturation, and entry into host cells. Furthermore, its cleavage specificity for viruses, but not humans, makes it a promising drug target for the treatment of coronavirus disease 2019 (COVID-19). In this study, a fragment-based strategy including potential antiviral quinazolinone moiety and glutamine- or glutamate-derived peptidomimetic backbone and positioned nitro functional groups was used to synthesize putative M^pro inhibitors. Two compounds, G1 and G4, exhibited anti-M^pro enzymatic activity in a dose-dependent manner, with the calculated IC₅₀ values of 22.47 ± 8.93 μM and 24.04 ± 0.67 μM, respectively. The bio-layer interferometer measured real-time binding. The dissociation kinetics of G1/M^pro and G4/M^pro also showed similar equilibrium dissociation constants (K_D) of 2.60 × 10^-5 M and 2.55 × 10^-5 M, respectively, but exhibited distinct association/dissociation curves. Molecular docking of the two compounds revealed a similar binding cavity to the well-known M^pro inhibitor GC376, supporting a structure-function relationship. These findings may open a new avenue for developing new scaffolds for M^pro inhibition and advance anti-coronavirus drug research.

4-(3H)-quinazolinones N-3 substituted with a five membered heterocycle: A promising scaffold towards bioactive molecules

The quinazolinone nucleus represents, among the class of fused heterocycles, a very important scaffold to obtain molecules with biological activities. A review of literature revealed how such kind of fused heterocycles, coming from natural or synthetic source, are associated with a wide range of biological activities. This review is mainly directed towards the 4-(3H)-quinazolinones N-3 substituted with a five membered heterocycle in which all the possible combinations of nitrogen, sulfur and oxygen atoms are present.

Synthetic and therapeutic perspectives of nitrogen containing heterocycles as anti-convulsants

Epilepsy is one of the commonly prevailing neurological disorders. According to the reports, it is evident that about 80% of the epileptic cases have been observed in developing countries. Although there are many drugs with significant potency available in the market; still there is an issue of selectivity and toxicity. Therefore, continuous attempts have been made by the researchers to develop newer therapeutic agents against epilepsy. Many synthetic strategies have been available in the literature to synthesize various classes of anticonvulsants with promising activity. In the presented review, authors have summarized some newer synthetic routes being used for the synthesis of nitrogen-containing anticonvulsants taking a cue from the reported established anticonvulsant drugs viz. vigabatrin, sodium valproate, oxcarbazepine, felbamate, retigabine, and gabapentin. Various derivatives with the substitution for better anticonvulsant profile have been described in the figures for easy comparative study. The structure-activity relationship (SAR) of compounds with maximum potency has also been discussed. This article may serve as a boost for the researchers to modify the pre-existing synthetic routes as well as to improve potency and yield of the compounds.

A Review Exploring Therapeutic Worth of 1,3,4-Oxadiazole Tailored Compounds

1,3,4-Oxadiazole, a five-membered aromatic ring can be seen in a number of synthetic molecules. The peculiar structural feature of 1,3,4-oxadiazole ring with pyridine type of nitrogen atom is beneficial for 1,3,4-oxadiazole derivatives to have effective binding with different enzymes and receptors in biological systems through numerous weak interactions, thereby eliciting an array of bioactivities. Research in the area of development of 1,3,4-oxadiazole-based derivatives has become an interesting topic for the scientists. A number of 1,3,4-oxadiazole based compounds with high therapeutic potency are being extensively used for the treatment of different ailments, contributing to enormous development value. This work provides a systematic and comprehensive review highlighting current developments of 1,3,4-oxadiazole based compounds in the entire range of medicinal chemistry such as anticancer, antifungal, antibacterial, antitubercular, anti-inflammatory, antineuropathic, antihypertensive, antihistaminic, antiparasitic, antiobesity, antiviral, and other medicinal agents. It is believed that this review will be of great help for new thoughts in the pursuit for rational designs for the development of more active and less toxic 1,3,4-oxadiazole based medicinal agents.