TITLE:
Synthesis and evaluation of diphenol aldimines as inhibitors of Escherichia coli ATPase and cell growth
AUTHORS:
Zulfiqar Ahmad, Prasanna K. Dadi, Jesse Elord, Ismail O. Kady
KEYWORDS:
Aldimine; ATPase; ATP Synthase; Diphenol; Polyphenol; Enzyme Inhibition; E. coli
JOURNAL NAME:
Advances in Biological Chemistry,
Vol.2 No.2,
May
10,
2012
ABSTRACT: A series of structurally related diphenol aldimines (DPAs) were synthesized. These aldimines involve different substitution patterns of their phenolic groups, for the purpose of optimizing their ability to inhibit ATP synthase. The inhibitory effects of these DPA compounds were evaluated using purified F1 and membrane-bound F1F0 E. coli ATP synthase. Structure-activity relationship studies of these di-phenol compounds showed that maximum inhibition was achieved when both phenolic groups are either in the meta-positions (DPA-7, IC50 = 2.0 μM), or in the ortho-positions (DPA-9, IC50 = 5.0 μM). The lowest ATP synthase inhibition was found to be when the phenolic groups are both in the para-positions (DPA-2, IC50 = 100.0 μM). Results also show that the inhibitory effects of these compounds on ATPase are completely reversible. Identical inhibition patterns of both the purified F1 and the membrane bound F1F0 enzyme were observed. Study of E. coli cell growth showed that these diphenol aldimines effectively inhibit both ATP synthesis and cell growth.