18-Crown-6-ether

18-Crown-6-ether is a type of crown ether compound and a specific structure dissociating agent. 18-Crown-6-ether can compete with K⁺ for binding to G-quadruplexes, disrupting their stable structure to regulate the functions of related systems. 18-Crown-6-ether combines with K⁺ and other metal ions to achieve precise ion transmembrane transport. 18-Crown-6-ether can act as an "susceptibility substrate" for the multi-drug efflux pump EmrE (a bacterial multidrug resistance transporter), ultimately inhibiting bacterial growth. 18-Crown-6-ether can be used in microcapsule controlled release and the research on developing antibacterial enhancers^[1][2][3]. In Vitro:18-Crown-6-ether exhibits selectivity towards K⁺. The 18-crown-6-K⁺ complex has a higher transmembrane permeation rate than the Na⁺ complex, mainly due to the higher geometric matching degree between the ionic radius of K⁺ and the molecular cavity of the compound^[2].
18-Crown-6-ether allosteric modulates EmrE, converting it from a normal anti-pump to a proton channel, triggering uncoupled proton leakage, thereby dissipating the proton motive force (PMF) of the bacteria and ultimately inhibiting their growth^[2].