In the last decade, quinazoline was one of the most explored scaffolds by researchers around the globe in medicinal chemistry. Its unique structural features provide a wide range of substitutions on nitrogen and carbonyl groups. In the current situation of COVID-19, hydroxychloroquine an antimalarial drug of the quinoline category was used for the treatment of severe infections. Various substitution patterns, hybrids, and conjugates of quinazoline have been developed and studied for various pharmacological activities like anticancer, anti-inflammatory, antimalarial, antitubercular, etc. The scaffold can be considered as a potential molecule for various pharmacological activities especially as antimicrobial and antihypertensive. The current review aims to study, physicochemical properties, chemistry, and pharmacological profile of quinazoline.

Background: The organic and peptide synthesis, various nanotechnology, and biochemistry processes are being carried out using microwave irradiation. The use of microwaves for synthesis has increased in the past two decades. The microwave offers several advantages such as ease of handling, lesser reaction times, quality of the product, and eco-friendly, which is green. The conventional method of synthesis, on the other hand, requires a longer time, is difficult to handle and maintenance of temperature is also difficult. The use of microwave-assisted reactions over conventional methods is advantageous in medicinal chemistry research as they will be less time-consuming and crucial in drug discovery and development. On the other side, they might not work in bulk synthesis due to their limited capacity for loading the reaction mixture. Objective: The present work aims to compare reaction time, temperature and percentage of yield of the microwave-assisted synthesis method against the conventional method. Method: A novel, simple, and green method was developed for the synthesis of tri-substituted imidazoles by microwave irradiation. Both derivatives from conventional and microwave-assisted synthesis were characterized by IR spectroscopy, Mass spectrometry, and 1H-NMR spectroscopy. The same derivatives were also synthesized by the conventional method for comparison. Result: A comparison of both methods was made by comparing the reaction time and the percentage yield. It was found that microwave-assisted reactions produced greater yield in the minimal time, though at different reaction temperatures. Conclusion: It can be concluded from the present comparison study that the use of the microwave for synthesis provides numerous advantages; thus, newer molecules are developed quickly anthat are developed quickly. To further proceed in this direction and to produce evidences, synthesis of more derivatives may be required. The only disadvantage is that it cannot be used for bulk synthesis of the compounds.

Leishmaniasis is one of the most devastating and fatal diseases in humans that has been known to mankind and is caused by the parasite Leishmania. It is destructive since no vaccination is available and existing medicines are proving ineffective because of resistance development. A need for the discovery of newer drugs has emerged. The use of natural products for the prevention, diagnosis, and cure of diseases has rapidly increased. Following the trend, research in the field of natural products for treating leishmaniasis has also picked up. In the present review, the focus is on terpenes as anti-leishmanial agents. Terpenes are the least studied natural products for the treatment of the disease. The other part of the review covers the use of chitosan as an anti-leishmanial agent and other formulations of chitosan as a carrier in nano-formulations. From the survey, it was found that the essential oils containing terpenes are very effective. Moreover, the chitosan-based nanocarriers showed potent anti-leishmanial activity. The combined use of natural products and newer technologies for the delivery of drugs can eradicate various diseases.

Introduction: Nitrogen containing heterocycles such as azoles have gained popularity in medicinal chemistry research due to their versatile pharmacological activities. Imidazole’s are one such class of adaptable compounds. The aim of the study was to explore pharmacological activities of 2,4,5-trisubstituted imidazole’s and also to develop a novel method of synthesis using microwave chemistry. Methods: In the present study, the in-silico studies of 2,4,5-trisubstituted imidazole’s was carried out to predict their anti-leishmanial as well as COX-2 inhibitory activity. Although, the results are not satisfactory for the anti-leishmanial activity, the molecules showed comparable docking scores with standard celecoxib for the COX-2 inhibitory activity. Later, the microwave-assisted green synthesis of tri-substituted imidazole’s was attempted using green catalyst and solvent, molecular iodine and ethanol respectively. The synthesised derivatives (TG-1-4) were purified and characterised. Results: The derivatives were subjected to in-vitro COX-2 inhibitory assay, which showed good results. The molecules under study showed exemplary results against COX-2 PDB in molecular docking studies. A novel microwave-irradiation method was developed for the synthesis and also the in-vivo studies carried out for testing COX-2 inhibition was fruitful. method: the microwave-assisted green synthesis of tri-substituted imidazole’s was attempted using green catalyst and solvent, molecular iodine and ethanol respectively. The synthesised derivatives were purified and characterised. Conclusion: In conclusion, the selected derivatives can be further studied in-vivo to develop new COX-2 inhibitors. other: -