Mechanochemical synthesis of cyclohexenones and indazoles as potential antimicrobial agents
作者:Abdullah S. Al-Bogami
DOI:10.1007/s11164-015-2379-5
日期:2016.6
Mechanical force from ball milling was used for efficient and quantitative preparation of a series of cyclohexenones and indazoles. The method is environmentally friendly, simple, short, and solventless. Unambiguous structural assignments of the obtained cyclohexenones were achieved based on single-crystal X-ray diffraction. The structures of the indazoles were characterized using Fourier-transform infrared spectroscopy, hydrogen and carbon nuclear magnetic resonance (NMR) spectroscopy, homonuclear correlation spectroscopy, distortionless enhancement by polarization transfer (DEPT) NMR, and gas chromatography–mass spectrometry. The synthesized compounds were screened for antimicrobial activity against two Gram-positive bacteria (methicillin-resistant staphylococcus aureus and Micrococcus luteus), three Gram-negative bacteria (Klebsiella oxytoca, Salmonella typhimurium, and Shigella sonnei), and three fungi (Candida albicans, Aspergillus niger, and A. flavus). The effects that different substituents on the synthesized compounds had on the antibacterial and antifungal activities were evaluated. Cyclohexenone derivatives with thiophene moiety at 4-position showed antibacterial activity comparable to the antibiotic tetracycline.
利用球磨产生的机械力高效、定量地制备了一系列环己烯酮和吲唑。该方法环保、简便、时间短且无溶剂。根据单晶 X 射线衍射,获得的环己烯酮的结构分配非常明确。利用傅立叶变换红外光谱、氢和碳核磁共振(NMR)光谱、同核相关光谱、无畸变极化传递增强(DEPT)NMR 和气相色谱-质谱法对吲唑类化合物的结构进行了表征。对合成的化合物进行了抗菌活性筛选,以检测其对两种革兰氏阳性菌(耐甲氧西林金黄色葡萄球菌和黄体微球菌)、三种革兰氏阴性菌(克雷伯菌、鼠伤寒沙门氏菌和宋内志贺氏菌)以及三种真菌(白色念珠菌、黑曲霉和黄曲霉)的抗菌活性。评估了不同取代基对合成化合物抗菌和抗真菌活性的影响。在 4 位上带有噻吩分子的环己酮衍生物显示出与抗生素四环素相当的抗菌活性。