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  • carbonyl
  • The second is called "Cohen's parameter", c, and is the distance between the carbon atom of the carboxylate and the oxygen atom of the β-lactam carbonyl. (wikipedia.org)
  • The imine can be replaced by adding olefin to produce a cyclobutanone, carbonyl to produce a β-lactone, or carbodiimides to produce 4-imino β-lactams. (wikipedia.org)
  • cephalosporins
  • It is now well established that the penicillins and the cephalosporins, the two main groups of antibiotics containing a β lactam ring stimulate in man and in experimental animals a specific immunological response (for recent reviews see Schwartz 1969, Parker 1972, Schneider 1970). (springer.com)
  • It appears that cross-reactivity between penicillins and cephalosporins is more likely associated with structurally similar side chains rather than the beta-lactam ring itself. (pharmacytimes.com)
  • precursors
  • Inhibition of cross-linkage by β-lactams causes a build-up of peptidoglycan precursors, which triggers the digestion of existing peptidoglycan by autolytic hydrolases without the production of new peptidoglycan. (wikipedia.org)
  • compounds
  • A process for preparing N-substituted lactams, as well as pharmaceutical compositions containing these compounds as active component. (google.com)
  • Until 2003, when measured by sales, more than half of all commercially available antibiotics in use were β-lactam compounds. (wikipedia.org)
  • broad-spectrum
  • The broad-spectrum beta-lactams cefepime, meropenem, and piperacillin-tazobactam are the agents most studied for this dosing strategy, as they have reliable activity against most gram-negative organisms, including Pseudomonas aeruginosa. (uspharmacist.com)
  • At first, β-lactam antibiotics were mainly active only against Gram-positive bacteria, yet the recent development of broad-spectrum β-lactam antibiotics active against various Gram-negative organisms has increased their usefulness. (wikipedia.org)
  • mainly
  • Ketenes with strong electron-donating substituents mainly produce cis β-lactams, while ketenes with strong electron-withdrawing substituents generally produce trans β-lactams. (wikipedia.org)
  • attacks
  • The tertiary amine contained within the quinuclidine can act as a nucleophile that attacks the most electrophilic carbon of the ketene to promote the formation of β-lactams. (wikipedia.org)
  • patient
  • Understanding the possible cross-reactivity will help a provider assess the risk to the patient and ultimately decide whether a nonpenicillin beta-lactam should be used. (pharmacytimes.com)
  • In vitro data, skin tests, and patient challenge studies found no risk of cross-reactivity to other beta-lactam allergies. (pharmacytimes.com)
  • form
  • Generally, (E)-imines form cis β-lactams while (Z)-imines form trans β-lactams. (wikipedia.org)
  • A Wolff Rearrangement of the diazoacetoacetate enone (pink) forms a stable ketene, which reacts with the imine to form a stable β-lactam compound. (wikipedia.org)
  • found
  • This strain is further increased by fusion to a second ring, as found in most β-lactam antibiotics. (wikipedia.org)
  • The lactam has found several applications in targeting an array of different diseased conditions by providing various non-nucleoside therapeutic molecules as well. (wikipedia.org)
  • high
  • 11-13 Because most beta-lactams have high renal excretion and renal dysfunction prolongs drug elimination, prolonging drug infusion is unlikely to improve PTA in patients receiving these agents. (uspharmacist.com)