title: Synthesis and evaluation of ketophosph(on)ates as beta-lactamase inhibitors.
abstract: A series of amidoketophosph(on)ates of general structure PhCH2OCONHCH(R)COCHR'(CH2)n(O)P(O2-)(O)R'' (R = H, CH3; R' = H, CH3; n = 0, 1; R'' = H, CH3, Et, Ph) have been prepared as a potential source of beta-lactamase inhibitors. The phosphonates (n = 0) were obtained by means of the Arbuzov reaction while most of the phosphates were achieved from reaction of phosph(or/on)ic acids with the appropriate diazoketone PhCH2OCONHCH(R)COCR'N2. The electrophilicity of the carbonyl group in the resulting phosph(on)ates was assessed by the degree of hydration in aqueous solution, determined from NMR spectra. These compounds inhibited typical class C and class D beta-lactamases, particularly the latter group, but showed no activity against class A enzymes. To enhance the carbonyl electrophilicity, an alpha-difluorinated analogue (R = H, CHR' = CF2, n = 0, R'' = Et) was also prepared, but no enhanced inhibitory activity was observed. All evidence suggested that these compounds inhibited in the carbonyl form rather than by formation of tetrahedral adducts at the beta-lactamase active site. They show promise as leads to specific class D beta-lactamase inhibitors.
authors.affiliation: Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, USA.
authors.forename: Senthil K
authors.initials: SK
authors.lastname: Perumal
authors.forename: R F
authors.initials: RF
authors.lastname: Pratt
mesh_terms: D004353:Drug Evaluation, Preclinical; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D015394:Molecular Structure; D063065:Organophosphonates / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D065093:beta-Lactamase Inhibitors
chemical_list: D004791:Enzyme Inhibitors; D063065:Organophosphonates; D065093:beta-Lactamase Inhibitors