- Novel Cephalosporin Conjugates Display Potent and Selective Inhibition of Imipenemase-Type Metallo-β-Lactamases
-
In an attempt to exploit the hydrolytic mechanism by which β-lactamases degrade cephalosporins, we designed and synthesized a series of novel cephalosporin prodrugs aimed at delivering thiol-based inhibitors of metallo-β-lactamases (MBLs) in a spatiotemporally controlled fashion. While enzymatic hydrolysis of the β-lactam ring was observed, it was not accompanied by inhibitor release. Nonetheless, the cephalosporin prodrugs, especially thiomandelic acid conjugate (8), demonstrated potent inhibition of IMP-type MBLs. In addition, conjugate 8 was also found to greatly reduce the minimum inhibitory concentration of meropenem against IMP-producing bacteria. The results of kinetic experiments indicate that these prodrugs inhibit IMP-type MBLs by acting as slowly turned-over substrates. Structure-activity relationship studies revealed that both phenyl and carboxyl moieties of 8 are crucial for its potency. Furthermore, modeling studies indicate that productive interactions of the thiomandelic acid moiety of 8 with Trp28 within the IMP active site may contribute to its potency and selectivity.
- Tehrani, Kamaleddin H. M. E.,Wade, Nicola,Mashayekhi, Vida,Brüchle, Nora C.,Jespers, Willem,Voskuil, Koen,Pesce, Diego,Van Haren, Matthijs J.,Van Westen, Gerard J. P.,Martin, Nathaniel I.
-
-
Read Online
- Determination of optimal operation conditions for production of cephalosporin g from penicillin g potassium
-
Cephalosporin G (Ceph-G) is one of the most important components for producing β-lactam antibiotics. It is also a starting material for the synthesis of cephalosporin antibiotics. Ceph-G was produced from penicillin G potassium (Pen-G.K.) during multiple steps consisting of conversion of Pen-G.K. to penicillin G sulfoxide followed by dehydration and ring expansion to produce Ceph-G. In this work, the amount of all starting materials and stoichiometric ratios were balanced, and the optimum values were determined. In addition, the process was optimized to evaluate the parameters affecting the scale-up of our test apparatus from laboratory to pilot scale. Difficulties for the industrial production of Ceph-G have been considered, and the production cost has been considerably decreased. In this research, Ceph-G with high purity more than 98% and high yield more than 94% was obtained.
- Salehpour, Pooneh,Yegani, Reza,Hajmohammadi, Reza
-
-
Read Online
- CEPHALOSPORIN-TYPE COMPOUNDS
-
The present technology is directed to compounds, compositions, and methods related to the treatment of bacterial and fungal infections. The compounds are of Formula I or stereoisomers, tautomers, solvates, and/or pharmaceutically acceptable salts thereof. The present technology is especially well-suited for use in treating non-replicating Mycobacterium tuberculosis.
- -
-
Paragraph 0134; 0135
(2017/12/09)
-
- A facile synthesis of 7-amino-3-desacetoxycephalosporanic acid derivatives by indium-mediated reduction of 3-iodomethylcephems in aqueous media
-
An efficient reductive conversion of 3-iodomethylcephalosporin and 3- acetoxymethylcephalosporin derivatives mediated by indium into the corresponding 3-methylcephems and 3-methylenecephams in moderate to good yields has been developed in an aqueous system. 3-Methylenecephams are converted into the corresponding 3-methylcephems under previously reported basic conditions quantitatively. (C) 2000 Elsevier Science Ltd.
- Chae, Hyungsun,Cho, Sangwon,Keum, Gyochang,Kang, Soon Bang,Pae, Ae Nim,Kim, Youseung
-
p. 3899 - 3901
(2007/10/03)
-
- De-esterification process
-
An efficient process for de-esterification has been provided for by application of special tetrahalogenides. By applying this process a new compound, viz. cefesone, and especially the E-isomer thereof, has been prepared.
- -
-
-
- Titanium tetrachloride promoted hydrolysis of cephalosporin tert-butyl esters
-
Titanium tetrachloride was used as a mild and effective deprotective reagent for the hydrolysis of cephalosporin tert-butyl esters. Yields up to 91% were obtained.
- Valencic, Marjan,Van Der Does, Thom,De Vroom, Erik
-
p. 1625 - 1628
(2007/10/03)
-
- Mechanism of β-lactam ring opening in cephalosporins
-
The mechanism of the aminolysis of cephalosporins is a stepwise process. A tetrahedral intermediate is formed by the reversible addition of the amine to the beta -lactam carbonyl carbon. Expulsion of the attacking amine from the tetrahedral intermediate occurs faster than fission of the beta -lactam C-N bond. The reaction proceeds by trapping the intermediate with base. Expulsion of a leaving group at C-3 prime in cephalosporins is not concerted with nucleophilic attack of the amine on the beta -lactam carbonyl carbon and makes little difference to the rate of beta -lactam C-N bond fission.
- Page,Proctor
-
p. 3820 - 3825
(2007/10/02)
-