New aromatic inhibitors of EPSP synthase incorporating hydroxymalonates as novel 3-phosphate replacements

• Published in: Bioorganic & medicinal chemistry Vol. 5; no. 2; pp. 323 - 334
• Main Authors: Shah, Ajit, Font, Jose L., Miller, Michael J., Ream, Joel E., Walker, Mark C., Sikorski, James A.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.1997
• Subjects: 3-Phosphoshikimate 1-Carboxyvinyltransferase; Alkyl and Aryl Transferases; Enzyme Inhibitors - chemical synthesis; Enzyme Inhibitors - chemistry; Enzyme Inhibitors - pharmacology; Escherichia coli - genetics; Magnetic Resonance Spectroscopy; Molecular Conformation; Phosphates - chemistry; Recombinant Proteins - antagonists & inhibitors; Tartronates - chemistry; Transferases - antagonists & inhibitors
• ISSN: 0968-0896; 1464-3391
• DOI: 10.1016/S0968-0896(96)00239-8

A new, aromatic analogue of the EPSP synthase enzyme reaction intermediate 1 has been identified, which contains a 3-hydroxymalonate moiety in place of the usual 3-phosphate group. This simplified inhibitor was readily prepared in five steps from ethyl 3,4-dihydroxybenzoate. The resulting tetrahedral intermediate mimic 9 is an effective, competitive inhibitor versus S3P with an apparent K i of 0.57±0.06 μM. This result demonstrates that 3-hydroxymalonates exhibit potencies comparable to aromatic inhibitors containing the previously identified 3-malonate ether replacements and can thus function as suitable 3-phosphate mimics in this system. These new compounds provide another example in which a simple benzene ring can be used effectively in place of the more complex shikimate ring in the design of EPSP synthase inhibitors. Furthermore, the greater potency of 9 versus the glycolate derivative 10 and the 5-deoxy-analog 11, again confirms the requirement for multiple anionic charges at the dihydroxybenzoate 5-position in order to attain effective inhibition of this enzyme. All rights reserved. Aromatic analogues of the EPSP synthase reaction substrate, product, and tetrahedral intermediate were synthesized from 3,4-dihydroxybenzoic acid, containing a 3-hydroxymalonate in place of the normal 3-phosphate group. These molecules help define the scope and limitations of incorporating 3-hydroxymalonates as 3-phosphate replacements in this system.