Abstract

An efficient and facile synthesis of substituted novel benzimidazoles (3a–3h) mediated by fruit juices viz. Cocos nucifera L. juice, Citrus limetta juice and Citrus sinensis L. juice, via condensation of substituted aldehydes (1a–1h) and o-phenylenediammine (2a) under solvent-free condition at room temperature is presented in this paper. The purity of compounds was confirmed by melting point and thin layer chromatography. All synthesized compounds (3a–3h) were fully characterized via NMR and FTIR spectral data and evaluated for in vitro herbicidal activity against Raphanus sativus L. (Radish) seeds. The compounds (3a–3h) were also evaluated for their antibacterial activity against Erwinia cartovora and Xanthomonas citri by inhibition zone method. Antifungal activity was also determined against Rhizoctonia solani and Colletotrichum gloeosporioides by poisoned food techniques method. From activity data, it was found that compounds 3d and 3e were most active against R. sativus L. (root) and R. sativus L. (shoot), respectively. Compound 3g has shown maximum inhibition zone i.e. 8.00 mm against E. cartovora at 2000 µg/mL concentration. Maximum X. citrii growth was inhibited by compounds 3a showing inhibition zone 5.20 mm at highest concentration. Compound 3f was found most active against R. solani and C. gloeosporioides fungus at 2000 µg/mL concentration. In comparison with the conventional methods, the present method complies with several key requirements of green chemistry principles such as the utilization of renewable feedstock, auxiliary aqueous conditions and reduces waste with the use of nature-derived catalyst. Therefore, the present method offers an attractive option because of its ecological safety, environmental acceptance, cost effective and easy workup process.

Graphic abstract

中文翻译：

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无溶剂条件下室温下合成新型苯并咪唑及其生物学研究

摘要

果汁介导的新型苯并咪唑（3a - 3h）的高效合成方法。本文介绍了在室温下无溶剂条件下，通过取代醛（1a – 1h）和邻苯二胺（2a）的缩合反应，可可椰子汁，柑桔汁和柑桔汁。化合物的纯度通过熔点和薄层色谱法确认。所有合成的化合物（3a – 3h）通过NMR和FTIR光谱数据进行了充分表征，并评估了对萝卜（Raphanus sativus L.）（萝卜）种子的体外除草活性。还通过抑制区法评估了化合物（3a – 3h）对卡氏欧文氏菌和柠檬黄单胞菌的抗菌活性。还通过中毒食品技术方法测定了对茄状枯萎病菌和球形炭疽菌的抗真菌活性。从活性数据发现，化合物3d和3e对R 3最具活性。sativus L.（根）和R。sativus L.（拍摄）。化合物3g显示出最大的抑制区，即针对E的8.00mm 。Cartovora浓度为2000 µg / mL。最大X。化合物3a抑制了柠檬的生长，在最高浓度下显示出5.20 mm的抑制区。发现化合物3f对R最有活性。菌和C。球孢子虫浓度为2000 µg / mL的真菌。与常规方法相比，本方法符合绿色化学原理的几个关键要求，例如可再生原料的利用，辅助水性条件，并通过使用天然催化剂来减少浪费。因此，本方法由于其生态安全性，环境可接受性，成本有效和后处理过程而提供了有吸引力的选择。

图形摘要