This review highlights recent developments in the microwave-assisted organic synthesis of N- and O-containing heterocycles with specific examples of pyrazolopyrimidines-, coumarin-, quinoline-, and isatin-based scaffolds and their associated biological activities.

C-glycosides are important class of molecules exhibit diverse biological activities and present as structural motif in many natural products. Two series of new pyrazoline and isoxazole bridged indoleC-glycoside molecular hybrids (n = 36) were efficiently synthesized starting from diverse indole 3-carboxaldehydes derived α, β-unsaturated ketone derivatives of β-D-glucosyl-propan-2-one, β-D-galactosyl-propan-2-one and β-D-mannosyl-propan-2-one, reacting with hydrazine hydrate and hydroxyl amine hydrochloride in shorter reaction time (15 min) under microwave assisted condition. Anticancer activity of these newly synthesized pyrazoline and isoxazole bridged indolesC-glycoside hybrids were determined in details through cellular assays against MCF-7, MDA-MB-453 and MDA-MB-231 cancer cell lines. The selected library members displayed low micromolar (IC₅₀ = 0.67–4.67 µM) and selective toxicity against breast cancer cell line (MCF-7). Whereas these compounds were nontoxic towards normal cell line (MCF-10A). Mechanistic studies showed that, active compounds inhibit COX-2 enzyme, which was also supported by molecular docking studies. These findings are expected to provide new leads towards anticancer drug discovery.

This review highlights the recent synthetic developments of benzothiazole based anti-tubercular compounds and their in vitro and in vivo activity. The inhibitory concentrations of the newly synthesized molecules were compared with the standard reference drugs. The better inhibition potency was found in new benzothiazole derivatives against M. tuberculosis. Synthesis of benzothiazole derivatives was achieved through various synthetic pathways including diazo-coupling, Knoevenagel condensation, Biginelli reaction, molecular hybridization techniques, microwave irradiation, one-pot multicomponent reactions etc. Other than recent synthetic developments, mechanism of resistance of anti-TB drugs is also incorporated in this review. Structure activity relationships of the new benzothiazole derivatives along with the molecular docking studies of selected compounds have been discussed against the target DprE1 in search of a potent inhibitor with enhanced anti-tubercular activity.