Department of Pesticide Chemistry and Technology, Faculty of Agriculture, Alexandria University, 21545 El-Shatby, Alexandria, Egypt.
Department of Plant Protection, Faculty of Agriculture, Damanhour University, Damanhour 22516, Egypt.
Pestic Biochem Physiol. 2019 Jul;158:185-200. doi: 10.1016/j.pestbp.2019.05.008. Epub 2019 May 16.
The present work describes the antimicrobial action of 25 monoterpenes (six hydrocarbons, five ketones, two aldehydes, six alcohols and six acetate analogues) against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus and antifungal activity against Aspergillus flavus. The antibacterial activity was evaluated by broth microdilution technique as a minimum inhibitory concentration (MIC) and the antifungal activity was performed by mycelia radial growth technique as the effective concentration causing 50% inhibition of the mycelial growth (EC). The results showed that thymol and α-terpineol were the most potent against E. coli (MIC = 45 and 55 mg/L, respectively) and S. aureus (MIC = 135 and 225 mg/L, respectively). The results also showed that thymol displayed the maximum antifungal action against A. flavus with EC 20 mg/L. Furthermore, the antioxidant activity was determined using N,N-dimethyl-1,4-phenylenediamine (DMPD) and the results showed that geraniol were the most potent compound (IC = 19 mg/L). Molecular docking studies indicated that the compounds displayed different binding interactions with the amino acid residues at the catalytic sites of N5-carboxyaminoimidazole synthetase and oxysterol binding protein Osh4 enzymes. Non-covalent interactions including van der Waals, hydrogen bonding as well as hydrophobic were observed between the compounds and the enzymes. A significant relationship was found between the docking score and the biological activity of the tested monoterpenes compared to the ceftriaxone and carbendazim as standard bactericide and fungicide, respectively. In silico ADMET properties were also performed and displayed potential for the development of promising antimicrobial agents. For these reasons, these compounds may be considered as potential ecofriendly alternatives in food preservation to delay or prevent the microbial infection and prolong the shelf life of food products.
本工作描述了 25 种单萜（六种烃类、五种酮类、两种醛类、六种醇类和六种醋酸酯类似物）对革兰氏阴性大肠杆菌和革兰氏阳性金黄色葡萄球菌的抗菌作用，以及对黄曲霉的抗真菌活性。抗菌活性通过肉汤微量稀释技术评估为最小抑菌浓度（MIC），抗真菌活性通过菌丝径向生长技术评估为导致菌丝生长抑制 50%的有效浓度（EC）。结果表明，对大肠杆菌（MIC=45 和 55mg/L）和金黄色葡萄球菌（MIC=135 和 225mg/L）最有效的是百里酚和α-松油醇。结果还表明，百里香对黄曲霉的抗真菌作用最大，EC20 为 20mg/L。此外，还使用 N，N-二甲基-1,4-苯二胺（DMPD）测定了抗氧化活性，结果表明香叶醇是最有效的化合物（IC=19mg/L）。分子对接研究表明，这些化合物与 N5-羧基氨基咪唑合成酶和氧化固醇结合蛋白 Osh4 酶的催化部位的氨基酸残基显示出不同的结合相互作用。在化合物和酶之间观察到非共价相互作用，包括范德华力、氢键以及疏水性。与头孢曲松和多菌灵作为标准杀菌剂相比，对接评分与测试的单萜的生物活性之间存在显著关系。还进行了虚拟 ADMET 性质，显示出开发有前途的抗菌剂的潜力。基于这些原因，这些化合物可能被认为是食品保鲜中潜在的环保替代品，以延迟或防止微生物感染并延长食品的保质期。
