Pseudomonas aeruginosa is an opportunistic Gram-negative bacterial pathogen. A primary contributor to its ability to resist β-lactam antibiotics is the expression, following detection of the β-lactam, of the AmpC β-lactamase. As AmpC expression is directly linked to the recycling of the peptidoglycan of the bacterial cell wall, an important question is the identity of the signaling molecule(s) ...

The use of three classical β-lactamase inhibitors (Clavulanic acid, tazobactam and sulbactam) in combination with β-lactam antibiotics is presently the mainstay of antibiotic therapy against Gram-negative bacterial infections. However these inhibitors are unable to inhibit carbapenemase KPC-2 effectively. They being β-lactam derivatives behave as substrates for this enzyme instead of inactivati...

β-lactamase mediated antibiotic resistance is an important health issue and the discovery of new β-lactam type antibiotics or β-lactamase inhibitors is an area of intense research. Today, there are about a thousand β-lactamases due to the evolutionary pressure exerted by these ligands. While β-lactamases hydrolyse the β-lactam ring of antibiotics, rendering them ineffective, Penicillin-Binding ...

Catalyzed by Rhodococcus erythropolis AJ270, a nitrile hydratase and amidase containing microbial whole cell catalyst, a number of racemic 1-arylmethyl- and 1-allyl-4-oxoazetidine-2-carbonitriles and carboxamides underwent efficient transformations under very mild conditions to produce enantiopure functionalized S-amide and R-acid products in excellent yields. While the nitrile hydratase showed...

Ring closing metathesis (RCM) reactions of α-methylene-β-lactams are used to construct strained 11- and 12-membered macrocycles that mimic key structural elements of phyllostictine A. The highest yield and stereoselectivity was achieved making 12-membered macrocycle Z-19 with use of a p-methoxyphenyl group on the lactam nitrogen. Interestingly, substrate concentration had an important influence...

Antibiotic allergy is one of the most commonly encountered problems in clinical practice. The symptoms may range from mildly annoying to life threatening. Drug allergies can become a major problem for patients with the multiple drug allergy syndrome, and more so since the emergence of antibiotic resistant organisms often limits the choice of antibiotics that can be used. β-lactam antibiotics (p...

Mycobacterial resuscitation-promoting factors (RPFs) have been of great interest since the discovery that they promote the growth of nonculturable Mycobacterium tuberculosis cells. Yet, their precise role in mycobacterial survival and infection has remained elusive. We performed a chemical screen to identify molecules that show preferential killing of a Mycobacterium tuberculosis mutant lacking...

In the title mol-ecule, C(36)H(25)NO(3), the β-lactam ring is essentially planar, with a dihedral angle of 3.3 (2)° between the two separate three-atom N/C/C planes. The β-lactam ring makes dihedral angles of 28.45 (14), 87.4 (1) and 51.8 (1)° with the mean planes of the benzene, xanthene and anthracene ring systems, respectively. In addition to a weak intra-molecular C-H⋯N hydrogen bond, the c...