II. The occurrence of modified penicillin-binding sites Modified PBPs have a lower affinity for β-lactam antibiotics, requiring clinically unattainable concentrations of the drug to effect its bactericidal activity Example: penicillin resistance in Streptococcus pneumoniae (pneumococcus) is caused by altered PBPs I. Production of β-lactamases This family of enzymes can inactivate penicillins by...

In the title compound, C37H34N2O7, both pyrrolidine rings adopt envelope conformations. The β-lactam ring is close to planar (r.m.s. deviation = 0.0395 Å) and makes a dihedral angle of 83.35 (15)° with the furan ring. The O atom attached to the β-lactam ring deviates by 0.187 (2) Å from the mean plane of the ring. The β-lactam ring makes dihedral angles of 14.90 (15) and 27.72 (17)° with the me...

introduction: septic shock is now recognized to be associated with multiple critical organ failure, usually attributable to the uncontrolled release of multiple pro-inflammatory cytokines such as tnf, inf, il-6, il-1, and no (nitric oxide). no is one of the most important proinflammatory mediators in sepsis and septic shock. it is a potent vasodilator, and appears to be responsible for hypotens...

The title compound, C(33)H(34)N(4)O(2)S·CH(3)OH, was prepared as a spiro-lactam ring formation of rhodamine 6 G dye for comparison with a ring-opened form. The xanthene and spiro-lactam rings are approximately planar [r.m.s. deviations from planarity = 0.122 (3) and 0.072 (6) Å, respectively]. The dihedral angles formed by the spiro-lactam and thio-phene rings with the xanthene ring system are ...

This article reviews the new beta-lactam (β-lactam) antibiotics doripenem, ceftobiprole, and ceftaroline. It covers pharmacokinetic and pharmacodynamic properties, dosing, in vitro activities, safety, and clinical trial results. Doripenem (Doribax) has been approved by the US Food and Drug Administration (FDA) for the treatment of complicated intra-abdominal and urinary tract infections. Ceftar...

Radioactiveand stable isotope-containing substrates were used to identify the biosynthetic precursors of the &lactam antibiotic, thienamycin, in Streptomyces cattleya. Acetate is utilized by the organism to form C(6) and C(7) of the &lactam ring. The two carbons of the hydroxyethyl group attached to C(6) are both derived from the methyl of methionine. The cysteaminyl side chain attached to C(2)...

The first synthesis of α-(trifluoromethyl)-β-lactam ((S)-1) is reported. The route starts from α-(trifluoromethyl)acrylic acid (2). Conjugate addition of α-(p-methoxyphenyl)ethylamine ((S)-3b), generated an addition adduct 4b which was cyclised to β-lactam 5b. Separation of the diastereoisomers by chromatography gave ((αS,3S)-5b). N-Debenzylation afforded the desired α-(trifluoromethyl)-β-lacta...

A beta-lactam-sensitive strain (C152) of Shigella dysenteriae showed two major outer membrane proteins (OMPs) with M(r)s of 43,000 and 38,000, while the clinical isolate M2 lacked the 43,000-Mr OMP, which acted as a channel for beta-lactam antibiotics. Permeability of beta-lactams across the outer membrane (OM) of M2 was lower than that across the OM of C152. Mutants deficient in the 43-kDa OMP...

Irreversible chemical programming of monoclonal aldolase antibody (mAb) 38C2 has been accomplished with beta-lactam-equipped targeting modules. A model study was first performed with beta-lactam conjugated to biotin. This conjugate efficiently and selectively modified the catalytic site lysine (LysH93) of mAb 38C2. We then conjugated a beta-lactam to a cyclic-RGD peptide to chemically program m...

β-Lactamases are the main cause of bacterial resistance to penicillins, cephalosporins and related β-lactam compounds. These enzymes inactivate the antibiotics by hydrolysing the amide bond of the β-lactam ring. Class A β-lactamases are the most widespread enzymes and are responsible for numerous failures in the treatment of infectious diseases. The introduction of new β-lactam compounds, which...