Yang Youjun, Severin Anatoly, Chopra Rajiv, Krishnamurthy Girija, Singh Guy, Hu William, Keeney David, Svenson Kristine, Petersen Peter J, Labthavikul Pornpen, Shlaes David M, Rasmussen Beth A, Failli Amedeo A, Shumsky Jay S, Kutterer Kristina M K, Gilbert Adam, Mansour Tarek S
Wyeth Research, 401 North Middletown Rd., Pearl River, NY 10965, USA.
Antimicrob Agents Chemother. 2006 Feb;50(2):556-64. doi: 10.1128/AAC.50.2.556-564.2006.
A series of 3,5-dioxopyrazolidines was identified as novel inhibitors of UDP-N-acetylenolpyruvylglucosamine reductase (MurB). Compounds 1 to 3, which are 1,2-bis(4-chlorophenyl)-3,5-dioxopyrazolidine-4-carboxamides, inhibited Escherichia coli MurB, Staphyloccocus aureus MurB, and E. coli MurA with 50% inhibitory concentrations (IC50s) in the range of 4.1 to 6.8 microM, 4.3 to 10.3 microM, and 6.8 to 29.4 microM, respectively. Compound 4, a C-4-unsubstituted 1,2-bis(3,4-dichlorophenyl)-3,5-dioxopyrazolidine, showed moderate inhibitory activity against E. coli MurB, S. aureus MurB, and E. coli MurC (IC50s, 24.5 to 35 microM). A fluorescence-binding assay indicated tight binding of compound 3 with E. coli MurB, giving a dissociation constant of 260 nM. Structural characterization of E. coli MurB was undertaken, and the crystal structure of a complex with compound 4 was obtained at 2.4 A resolution. The crystal structure indicated the binding of a compound at the active site of MurB and specific interactions with active-site residues and the bound flavin adenine dinucleotide cofactor. Peptidoglycan biosynthesis studies using a strain of Staphylococcus epidermidis revealed reduced peptidoglycan biosynthesis upon incubation with 3,5-dioxopyrazolidines, with IC50s of 0.39 to 11.1 microM. Antibacterial activity was observed for compounds 1 to 3 (MICs, 0.25 to 16 microg/ml) and 4 (MICs, 4 to 8 microg/ml) against gram-positive bacteria including methicillin-resistant S. aureus, vancomycin-resistant Enterococcus faecalis, and penicillin-resistant Streptococcus pneumoniae.
一系列3,5 - 二氧代吡唑烷被鉴定为UDP - N - 乙酰烯丙基葡糖胺还原酶（MurB）的新型抑制剂。化合物1至3为1,2 - 双（4 - 氯苯基）-3,5 - 二氧代吡唑烷 - 4 - 甲酰胺，对大肠杆菌MurB、金黄色葡萄球菌MurB和大肠杆菌MurA的50%抑制浓度（IC50）分别在4.1至6.8微摩尔/升、4.3至10.3微摩尔/升和6.8至29.4微摩尔/升范围内。化合物4是一种C - 4未取代的1,2 - 双（3,4 - 二氯苯基）-3,5 - 二氧代吡唑烷，对大肠杆菌MurB、金黄色葡萄球菌MurB和大肠杆菌MurC表现出中等抑制活性（IC50为24.5至35微摩尔/升）。荧光结合测定表明化合物3与大肠杆菌MurB紧密结合，解离常数为260纳摩尔。对大肠杆菌MurB进行了结构表征，并获得了与化合物4复合物的晶体结构，分辨率为2.4埃。晶体结构表明化合物在MurB的活性位点结合，并与活性位点残基和结合的黄素腺嘌呤二核苷酸辅因子有特异性相互作用。使用表皮葡萄球菌菌株进行的肽聚糖生物合成研究表明，与3,5 - 二氧代吡唑烷孵育后肽聚糖生物合成减少，IC50为0.39至11.1微摩尔/升。观察到化合物1至3（最低抑菌浓度，0.25至16微克/毫升）和4（最低抑菌浓度，4至8微克/毫升）对革兰氏阳性菌具有抗菌活性，包括耐甲氧西林金黄色葡萄球菌、耐万古霉素粪肠球菌和耐青霉素肺炎链球菌。
