- Cephalosporin-derived inhibitors of beta-lactamase. Part 4: The C3 substituent.
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New C3-substituted beta-lactamase inhibitors were prepared and evaluated against representative class A and class C enzymes. It was possible to improve simultaneous inhibitory activity of both classes of serine hydrolase. Other inhibitors showed high selectivity for either the class C cephalosporinases or the class A penicillinases. This represents the first time that cephalosporin-derived inhibitors have demonstrated selectivity for the class A beta-lactamases.
- Buynak, John D,Vogeti, Lakshminarayana,Doppalapudi, Venkata Ramana,Solomon, George Martin,Chen, Hansong
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p. 1663 - 1666
(2007/10/03)
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- Discovery of RWJ-54428 (MC-02,479), a new cephalosporin active against resistant gram-positive bacteria
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The discovery of RWJ-54428 (MC-02,479), a new cephalosporin displaying promising activity against sensitive and resistant Gram-positive bacteria, is described. Progressive structural modification from the previously reported 3-phenylthiocephem MC-02,331 afforded an overall increase in potency against MRSA while retaining other key properties such as acceptable solubility and serum binding. Evaluation of the in vitro potency and in vivo efficacy of a series of closely related compounds resulted in selection of RWJ-54428 (MC-02,479) for further studies.
- Hecker,Glinka,Cho,Zhang,Price,Chamberland,Griffith,Lee
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p. 1272 - 1281
(2007/10/03)
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- Synthesis and in Vitro Evaluation of New Cephalosporins Exhibiting Antimicrobial Activity Against Gram-Positive Bacteria, in Particular Methicillin-Resistant Staphylococci
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The preparation and biological evaluation of 7β-acetamido>cephalosporins and 7β-acetamido>cephalosporins, 9a-o, substituted at the 3-position with acetyloxymethyl, chlorine, hydrogen, and methyl are described.Hantzsch's thiazole synthesis is employed to provide thiazoleacetic acids 5a-e, subsequently followed by Morpho CDI-assisted amidation to complete the synthesis of target cephalosporins 9a-o.These compounds display activity selectively against Gram-positive bacteria, but are inactive against most Gram-negative bacteria tested.Those with acetyloxymethyl at the 3-position, i.e., 9a, 9e, 9i, 9m, and 9o, exhibit activity with minimal inhibitory concentrations of 16 μg/mL or lower against four strains of methicillin-resistant staphylococci, namely Staphylococcus aureus X400 and S13E and Staphylococcus epidermidis 270 and 222.Notably, 9a displays an activity profile similar to that of vancomycin regarding its spectrum and potency.Key Words: Gram-positive bacteria; Methicillin-resistant staphylococci; Cephalosporin; Thiazole synthesis; Amidation.
- Lin, Ho-Shen,Rampersaud, Ashraff A.,Flokowitsch, Jane E.,Alborn, William E.,Wu, Ernie C. Y.,Preston, David A.
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p. 833 - 846
(2007/10/03)
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- Synthesis and antibacterial activities of new (α-hydrazinobenzyl)cephalosporins
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Some (α-hydrazinobenzyl)cephalosporins, structurally related to cephalexin, cephaloglycin, and cefaclor have been prepared and evaluated in vitro for their antimicrobial activity. The synthesis involves the condensation of the chloride hydrochloride with
- Balsamo, A.,Macchia, B.,Macchia, F.,Rossello, A.,Giani, R.,et al.
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p. 1648 - 1650
(2007/10/02)
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