• In Chapter II, a unique strategy for enantioselective synthesis of bicyclic lactam N,S-acetals scaffolds was developed. (miun.se)
  • Next, the addition of thiol amine leads to the construction of bicyclic lactams via a imine/N,S-acetal formation/lactamization cascade sequence. (miun.se)
  • Efficient conversion of Schiff bases and carboxylic acids to β-lactams can be carried out at room temperature in CH 2 Cl 2 , using a cyanuric chloride- N,N -dimethyl formamide complex. (organic-chemistry.org)
  • Synthesis of substituted cytisine derivatives and labelling with fluorine-18. (ensicaen.fr)
  • Various 2-phenyl-1H-indoles and benzimidazole derivatives have been tested for total antioxidant capacity by phosphomolybednum reduction method and 2,2-diphenyl-1-picrylhydrazide free radical scavenging activity. (ijpsonline.com)
  • The present study was focused on evaluating substituted indole and benzimidazole derivatives ( Table 1 ) for total antioxidant capacity (TAC), free radical scavenging and antimicrobial activity. (ijpsonline.com)
  • Catalytic generation of a ketene species directly from a terminal alkyne in the presence of a Rh(I) catalyst and 4-picoline N -oxide provides a novel and efficient entry to the Staudinger synthesis of β-lactams with high trans diastereoselectivity under mild conditions. (organic-chemistry.org)
  • Thermally promoted reactions of α-acyl-α-diazoacetates with imines deliver α-alkoxycarbonyl-substituted β-lactams with outstanding diastereoselectivity. (organic-chemistry.org)
  • The resulting rhodium enolate reacted as a Reformatsky-type reagent with various imines to give syn -β-lactams in good to excellent yields with high diastereoselectivity. (organic-chemistry.org)
  • A catalytic, highly diastereoselective synthesis of trans -β-lactams is based on a phosphonium fluoride precatalyst that both activates the nucleophile and directs the reaction process for high yield and diastereoselectivity. (organic-chemistry.org)
  • Condensation of 2-formylbenzoic acid with α-amino alcohol substrates proceeds with extremely high diastereoselectivity to produce tricyclic γ-lactam products. (hud.ac.uk)
  • Resistant strains selected by treatment with β-lactams express variants of the target enzymes that do not recognize the drugs but retain their activity in cell wall building, despite the antibiotics being mimics of the natural substrate. (nih.gov)
  • Our study reveals that the high diversity of actinobacterial strains and their NPs derivatives, described here provides a new perspective and direction for the production of new anti-CRC drugs and paves the way to innovation for drugs discovery in the future. (frontiersin.org)
  • Functional characterization of KPC-109 was performed investigating the impact of KPC-109 production on the β-lactam resistance phenotype of various Escherichia coli and Klebsiella pneumoniae strains, including derivatives of K. pneumoniae with OmpK35 and OmpK36 porin alterations. (imperial.ac.uk)
  • Metallo-β-lactamase (MBL) enzymes in bacterial strains resistant to β-lactam antibiotics are capable of breaking down the β-lactam structure of, for example, carbapenem. (helsinki.fi)
  • RESULTS: Five strains of Staphylococcus aureus , plus Bacillus subtilis and Staphylococcus epidermidis were all found to be susceptible to the hydrophobic derivative EIPE-1, while other gram-positive and all gram-negative organisms exhibited resistant phenotypes at potencies tested. (okstate.edu)
  • The susceptibility of two methicillin-resistant S. aureus strains (SFL 8 and SFL 64) to EIPE-1 suggests that its mechanism of action does not involve the penicillin-binding proteins of peptidoglycan biosynthesis targeted by mainstream B-lactam antibiotics. (okstate.edu)
  • However, the original TEM-1 and TEM-2 hydrolyze only penicillin derivatives. (cdc.gov)
  • 2-Carboxyphenyl penicillin shows higher activity at low pH, while the 3,4- carboxyphenyl penicillin derivatives show a typical 'bell-shaped' profile, but with the pKa I value shifted up-field. (hud.ac.uk)
  • Hypersensitivity Reactions: Hypersensitivity reactions have been reported in patients receiving beta lactam drugs. (nih.gov)
  • Known hypersensitivity to product components or anaphylactic reactions to β-lactams. (nih.gov)
  • Serious hypersensitivity (anaphylactic) reactions have been reported in patients receiving β-lactams. (nih.gov)
  • A practical methodology for the catalytic, asymmetric synthesis of β-lactams results from the development of a catalyzed reaction of ketenes (or their derived zwitterionic enolates) and imines using benzoylquinine as chiral catalyst and proton sponge as the stoichiometric base. (organic-chemistry.org)
  • Trotter, J. An Investigation Of The Solid-State Photochemistry Of Alpha-Mesitylacetophenone Derivatives: Asymmetric Induction Studies And Crystal Structure-Reactivity Relationships . (ubc.ca)
  • Trotter, J. Asymmetric Induction In The Solid State Photochemistry Of An Alpha-Mesitylacetophenone Derivative Through The Use Of Ionic Chiral Auxiliaries . (ubc.ca)
  • Despite this it is believed that the activesite of the B-lactamase I enzyme does not display a strong recognition for B-lactams containing a hydrophobic C6 side-chain. (hud.ac.uk)
  • The purpose of this study was to investigate the antibacterial potential of eumelanin-inspired phenylene indolyne (EIPE) derivatives EIPE-1 and EIPE-HCl which are hydrophobic and hydrophilic, respectively. (okstate.edu)
  • CONCLUSION: Hydrophobic EIPE derivative EIPE-1 clearly possesses a gram-positive antibacterial spectrum, although only certain organisms are susceptible at the potencies employed for this study. (okstate.edu)
  • Various trans -substituted β-lactams derived from amino acids have been prepared. (organic-chemistry.org)
  • Hydrogenation of the nitro group in some of the adducts leads to gamma-lactams, which can be easily converted into alpha-hydroxy-gamma-amino acid derivatives. (unboundmedicine.com)
  • In the latest study, an international group of researchers further developed and optimised compounds discovered by Schofield group at the University of Oxford that imitate in their binding function penicillins, cephalosporins, carbapenems and other antibiotics in the β-lactam group. (helsinki.fi)
  • METHODS: A standardized disk agar diffusion bioassay was employed to determine the susceptibility and resistance levels of 12 gram-positive and 13 gram-negative bacteria to nonpolar and polar EIPE derivatives. (okstate.edu)
  • Acetals of lactams and acid amides. (chemspider.com)
  • In the present study, we show that benzoic acid derivatives isolated from Bjerkandera adusta promote the activity of the two main protein degradation systems, namely the ubiquitin-proteasome (UPP) and especially the autophagy-lysosome pathway (ALP) in human foreskin fibroblasts. (mdpi.com)
  • Specifically, an amide can also be regarded as a derivative of a carboxylic acid in which the hydroxyl group has been replaced by an amine or ammonia . (wikidoc.org)
  • The Staudinger synthesis, an overall [2 + 2] cycloaddition of a ketene with an imine, provides a nicely convergent route to biologically and synthetically interesting β-lactams. (organic-chemistry.org)
  • A convenient Kinugasa reaction protocol enables a one-pot synthesis of 4-substituted β-lactams from inexpensive calcium carbide and nitrone derivatives. (organic-chemistry.org)
  • A planar-chiral derivative of 4-(pyrrolidino)pyridine serves as a very effective enantioselective catalyst coupling a range of symmetrical and unsymmetrical ketenes with various imines with very good stereoselection and yield. (organic-chemistry.org)
  • The reaction provides rapid access to practical quantities of β-lactams substituted at position 4. (organic-chemistry.org)
  • A chiral N-heterocyclic carbene catalyzed the Staudinger reaction of arylalkylketenes with a variety of N -tert-butoxycarbonyl arylimines to give the corresponding cis -β-lactams in good yields with good diastereoselectivities and excellent enantioselectivities. (organic-chemistry.org)
  • A catalytic enantioselective Staudinger reaction is described that preferentially furnishes trans β-lactams. (organic-chemistry.org)
  • Chapter III focuses on a stereodivergent synthesis of fluorinated lactams bearing two vicinal stereogenic centers by multicomponent reaction. (miun.se)
  • Until now, the crucial transpeptidase activity that is inhibited by β-lactams was not amenable to in vitro investigation with enzymes from Gram-positive organisms, including streptococci, staphylococci, or enterococci pathogens. (nih.gov)
  • The pH dependence of the B-lactamase enzymes I and 2 catalysed hydrolysis of penicillin and cephalosporin derivatives has been investigated. (hud.ac.uk)
  • A set of twenty-five thioxanthene-9-one and xanthene-9-one derivatives, that were previously shown to inhibit cholinesterases (ChEs) and amyloid β (Aβ40) aggregation, were evaluated for the inhibition of tau protein aggregation. (ibecbarcelona.eu)
  • The more polar EIPE-HCl derivative failed to inhibit growth of any of the organisms examined, regardless of gram reactivity. (okstate.edu)
  • In this review, the progress of cytisine and its derivatives in regard to bioactivities, total synthesis, structural modifications focusing on their N-12 position and lactam ring is reported. (nih.gov)
  • To a synthetic chemist, it provides an opportunity to synthesize a library of compounds based on a core scaffold and to screen the derivatives for various biological activities. (ijpsonline.com)
  • Vishnumurthy, K. The Photochemistry Of Trans-1,4,4,4-Tetraphenylbut-2-En-1-One: A Highly Efficient Aryl Migration (Type B) Enone Photorearrangement . (ubc.ca)
  • The current strategy employed can lead to the production of small libraries of azaspirene derivatives and other members of the pseurotin family, where structure activity relationship (SAR) studies can be conducted in anticipation of creating innovative and more effective anti-cancer drugs. (escholarship.org)
  • Enantioenriched, highly functionalized cyclopropane derivatives were prepared by a simple and green approach using monosaccharide‐based chiral crown ethers as phase transfer catalysts. (researchgate.net)
  • Additionally, the structure-activity relationships of cytisine and its derivatives are also discussed. (nih.gov)
  • Neither of the corresponding cepbalosporin derivatives showed evidence of higher activity at low pH. (hud.ac.uk)
  • The synthesis and properties of a series of unsymmetrical thienopentalenes are explored, including both monoareno and diareno derivatives. (researchgate.net)