Antimicrobial resistance is an ever-increasing problem throughout the world and has already reached severe proportions.
Bacteria can develop ways to render traditional antibiotics ineffective, raising a crucial need to find new antimicrobials with novel mode
of action. We demonstrate here a novel class of pyrazine functionalized Ag(I) and Au(I)-NHC complexes as antibacterial agents against
human pathogens that are resistant to several antibiotics. Complete synthetic and structural studies of Au(I) and Ag(I) complexes of 2-(1-
methylimidazolium) pyrimidinechloride (L-1), 2,6-bis(1-methylimidazol)pyrazinechloride (L-2) and 2,6-bis(1-methyl imidazol)
pyrazinehexa-fluorophosphate (L-3) are reported herein. Chloro[2,6-bis(1-methyl imidazol)pyrazine]gold(I), 2b and chloro [2,6-bis(1-
methyl imidazol)pyrazine]silver(I), 2a complexes are found to have more potent antimicrobial activity than other synthesized compounds
and several conventionally used antibiotics. Complexes 2b and 2a also inhibit the biofilm formation by Gram-positive bacteria,
Streptococcus mutans and Gram-negative bacteria, Escherichia coli, causing drastic damage to the bacterial cell wall and increasing
membrane permeability. Complexes 2b and 2a strongly binds to both Lys and Dap-Type peptidoglycan layers, which may be the reason
for damage to the bacterial cell wall. Theoretical studies of all the complexes reveal that 2b and 2a are more reactive than other
complexes, and this may be the cause of differences in antibacterial activity. These findings will pave the way towards developing a new
class of antibiotics against different groups of conventional antibiotic-resistant bacteria.
抗菌药耐药性是全世界日益严重的问题,目前已经达到了很严重的程度。 细菌可以开发出使传统抗生素失效的方法,因此亟需找到具有新作用模式的新型抗菌药。我们在此展示了一类新型
吡嗪官能化 Ag(I) 和 Au(I)-NHC 复合物,可作为抗菌剂对付对多种抗生素产生耐药性的人类病原体。本文报告了 2-(1-甲基
咪唑鎓)
嘧啶盐酸盐(L-1)、2,6-双(1-甲基
咪唑)
吡嗪盐酸盐(
L-2)和 2,6-双(1-甲基
咪唑)
吡嗪六氟磷酸盐(L-3)的 Au(I) 和 Ag(I) 复合物的完整合成和结构研究。研究发现,
氯[2,6-双(1-甲基
咪唑)
吡嗪]
金(I)2b 和
氯[2,6-双(1-甲基
咪唑)
吡嗪]
银(I)2a 复合物比其他合成化合物和几种常规抗生素具有更强的抗菌活性。络合物 2b 和 2a 还能抑制革兰氏阳性菌--变异链球菌和革兰氏阴性菌--大肠杆菌--形成
生物膜,对细菌细胞壁造成严重破坏,并增加膜的渗透性。复合物 2b 和 2a 能与赖
氨酸和 Dap 型肽聚糖层紧密结合,这可能是细菌细胞壁受损的原因。对所有复合物的理论研究表明,2b 和 2a 比其他复合物更具反应性,这可能是造成抗菌活性差异的原因。这些发现将为开发一类新的抗生素铺平道路,这种抗生素可以对付不同种类的传统抗生素耐药细菌。