Efficient and green multicomponent synthesis of some novel heterocyclic compounds and their bioefficacy
Loading...
Date
2021-01
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CCSHAU, Hisar
Abstract
Due to growing concern of environmental pollution, the application of green chemistry for the formation of bioactive heterocyclic functionalities has turned out to be a key area of research for organic chemists. Coumarins, dihydropyrimidinones, imidazoles, isoxazoles and benzimidazoles are important heterocyclic compounds occur widely in nature. The conventional methods for preparation of these heterocyclic molecules have some drawbacks such as use of hazardous solvents, toxic reagents, tedious work-up, low product yield and long reaction time. Therefore, the development of waste minimized organic synthesis has become key and challenging area for organic chemist. Natural acid catalysts viz. Citrus limon L. juice, Vitis vinifera L. juice, Banana peels extract, Cocos nucifera L. juice, Solanum lycopersicum L. juice, Citrus limetta juice and Citrus sinensis L. juice were prepared for synthesis of substituted coumarins (30-37), dihydropyrimidinones (45-52), imidazole (55-62), isoxazoles (65-72) and benzimidazoles (73-80). All synthesized compounds were characterized by using 1HNMR and FTIR spectral techniques and evaluated for antibacterial activity against Erwinia carotovora and Xanthomonas citrii by inhibition zone method. All synthesized compounds were also tested for antifungal activity against Rhizoctonia solani and Colletotrichum gloeosporioides by poisoned food technique method. Herbicidal activity against Raphanus sativus L. (Radish seeds) were also studied to test bioefficacy of synthesized compounds. It was found that maximum Erwinia carotovora growth was inhibited by compounds 37, 51, 56, 72 and 78. Maximum Xanthomonas citri growth inhibition was by compounds 31, 50, 57, 72 and 74. Compounds 31, 50, 58, 72 and 76 were found to be the most active against Rhizoctonia solani fungus while compounds 34, 47, 58, 67 and 76 have highest growth inhibition against Colletotrichum gloeosporioides fungus. It was found that compounds 30, 51, 60, 67 and 79 were most active against Raphanus sativus L. (root) while compounds 31, 48, 57, 67 and 75 found to be most active against Raphanus sativus L. (shoot). It was found that the activity of the synthesized compounds may be due to presence of bromo, chloro, methyl, hydroxy, methoxy and nitro groups substitution on the phenyl ring.