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1. Evaluation of benzthiazolidine-based formamidinium salts for the synthesis of penem-type β-lactams by uncatalysed carbonylation of acyclic diaminocarbenes

Author:
Jonek, Markus; Buhl, Hannes; Leibold, Michael; Bruhn, Clemens; Siemeling, Ulrich
Source:
Zeitschrift für Naturforschung 2019 v.74 no.4 pp. 365-372
ISSN:
1865-7117
Subject:
beta-lactams,   etc   ; X-ray diffraction; deprotonation; isomers; selenium;     Show all 5 Subjects
Abstract:
... The reaction of [iPr₂N=CHCl]Cl with 2-phenylbenzthiazolidine (Ph-BtzH) and subsequent anion metathesis afforded the formamidinium salt [(Ph-Btz)CH(NiPr₂)][PF₆] ([1aH][PF₆]). The reaction of [1aH][PF₆] with (Me₃Si)₂NNa in the presence of grey selenium furnished the selenourea derivative 1aSe as trapping product of the acyclic diaminocarbene 1a. In the absence of selenium, a 2H-1,4-benzothiazine der ...
DOI:
10.1515/znb-2019-0017

2. The reaction of a particularly electrophilic acyclic diaminocarbene with carbon monoxide: formation of β- and γ-lactams

Author:
Wallbaum, Lars; Schulz, Tim; Bruhn, Clemens; Siemeling, Ulrich
Source:
Zeitschrift für Naturforschung 2019 v.74 no.2 pp. 221-226
ISSN:
1865-7117
Subject:
beta-lactams,   etc   ; Lewis acids; carbenes; carbon monoxide; chemical reactions;     Show all 5 Subjects
Abstract:
... The reaction of carbon monoxide with the acyclic diaminocarbene iPr₂N–C–TMP (TMP=2,2,6,6-tetramethylpiperidino), generated in situ from the formamidinium salt [(iPr₂N)CH(TMP)][PF₆] and NaN(SiMe₃)₂, unexpectedly afforded a mixture of β- and γ-lactams. ...
DOI:
10.1515/znb-2018-0255

3. Asymmetric synthesis of aminocyclooctenecarbonitriles: Cyclooctene β-lactam and hydroxyaminocyclooctene carboxylic precursors

Author:
Aydin, Busra Ozturk; Yurtoglu, Emine; Arcelik, Nejat; Sahin, Ertan; Secen, Hasan; Altundas, Ramazan
Source:
Tetrahedron letters 2019 v.60 no.3 pp. 284-287
ISSN:
0040-4039
Subject:
beta-lactams,   etc   ; acid hydrolysis; amino acids; crystallization; enantiomers; ethyleneimine; moieties;     Show all 7 Subjects
Abstract:
... Enantiopure β-aminocyclooctenenitriles, as precursors of β-amino acids and β-lactams, were synthesized from a readily available chloroalkene nitrile and (S)-methylbenzylamine via a straightforward substitution reaction and purified by crystallization. Acidic hydrolysis of the nitrile groups to their corresponding amides followed by DCC assisted carbonyl group activation gave novel α,β-unsaturated ...
DOI:
10.1016/j.tetlet.2018.12.034

4. Mechanism of Integrated β-Lactam Formation by a Nonribosomal Peptide Synthetase during Antibiotic Synthesis

Author:
Long, Darcie H.; Townsend, Craig A.
Source:
Biochemistry 2018 v.57 no.24 pp. 3353-3358
ISSN:
1520-4995
Subject:
beta-lactams,   etc   ; antibiotics; biosynthesis; chemical bonding; ligases;     Show all 5 Subjects
Abstract:
... Modular nonribosomal peptide synthetases (NRPSs) are large, multidomain engines of bioactive natural product biosynthesis that function as molecular “assembly lines” in which monomer units are selectively bound, modified, and linked in a specific order and number dictated by their mega-enzyme templates. Recently, a condensation domain in an NRPS was discovered to carry out the synthesis of an inte ...
DOI:
10.1021/acs.biochem.8b00411

5. Breakpoint to MIC quotient: A parameter to rapidly evaluate the in vitro bactericidal activity of β-lactams on Enterobacteriaceae

Author:
Grillon, Antoine; Chabaud, Angeline; Zambardi, Gilles; Caniaux, Isabelle; Jehl, François
Source:
International journal of antimicrobial agents 2019 v.53 no.5 pp. 674-677
ISSN:
0924-8579
Subject:
beta-lactams,   etc   ; Enterobacteriaceae; antibacterial properties; antibiotic resistance; antibiotics; bacterial infections; minimum inhibitory concentration; pathogens; patients; risk;     Show all 10 Subjects
Abstract:
... Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) do not completely predict the bactericidal nature of the antimicrobial agent. Patients with pathogens having MICs near the clinical breakpoint experience a higher risk of clinical failure. This study defined an indicator, breakpoint to MIC quotient (BMQ), that incorporates MIC and the European Committee on Antimicr ...
DOI:
10.1016/j.ijantimicag.2019.01.013

6. Synthesis of N-aryl β-amino acid derivatives via Cu(ii)-catalyzed asymmetric 1,4-reduction in air

Author:
Li, Min; Xia, Hong-Feng; Yang, Li-Yao; Hong, Tao; Xie, Lin-Jie; Li, Shijun; Wu, Jing
Source:
RSC advances 2019 v.9 no.16 pp. 9187-9192
ISSN:
2046-2069
Subject:
beta-lactams,   etc   ; additives; air; amino acids; catalysts; copper; enantioselectivity; esters; reducing agents;     Show all 9 Subjects
Abstract:
... In the presence of the inexpensive and stable stoichiometric reductant polymethylhydrosiloxane (PMHS) as well as certain amounts of appropriate alcohol and base additives, the non-precious metal copper-catalyzed asymmetric 1,4-hydrosilylation of β-aryl or β-alkyl-substituted N-aryl β-enamino esters was well realized to afford a diverse range of N-aryl β-amino acid esters in high yields and excelle ...
DOI:
10.1039/c9ra01203f

7. Asymmetric Synthesis of α-Alkylidene-β-Lactams through Copper Catalysis with a Prolinol-Phosphine Chiral Ligand

Author:
Imai, Koji; Takayama, Yurie; Murayama, Hiroaki; Ohmiya, Hirohisa; Shimizu, Yohei; Sawamura, Masaya
Source:
Organic letters 2019 v.21 no.6 pp. 1717-1721
ISSN:
1523-7052
Subject:
beta-lactams,   etc   ; alcohols; alkynes; carbonyl compounds; catalysts; catalytic activity; chemical reactions; chemical structure; enantioselectivity; ligands;     Show all 10 Subjects
Abstract:
... A copper/prolinol-phosphine chiral catalyst enabled the one-step synthesis of chiral α-alkylidene-β-lactams. Optimization of the chiral ligand for steric and electronic properties realized the highly enantioselective coupling of nitrones and propargyl alcohol derived alkynes. The resulting chiral α-alkylidene-β-lactams served as a platform for various β-lactams via well-established transformations ...
DOI:
10.1021/acs.orglett.9b00276

8. Transmission routes of ESBL/pAmpC producing bacteria in the broiler production pyramid, a literature review

Author:
Dame-Korevaar, Anita; Fischer, Egil A.J.; van der Goot, Jeanet; Stegeman, Arjan; Mevius, Dik
Source:
Preventive veterinary medicine 2019 v.162 pp. 136-150
ISSN:
0167-5877
Subject:
beta-lactams,   etc   ; anti-infective agents; bacteria; beta-lactamase; databases; farms; hatcheries; humans; plasmids; poultry production;     Show all 10 Subjects
Abstract:
... Plasmid mediated Extended Spectrum Beta-Lactamase and AmpC Beta-Lactamase (ESBL/pAmpC) producing bacteria are resistant to beta-lactam antimicrobials and are widespread in humans, the environment and animals. Animals, especially broilers, are an important reservoir of ESBL/pAmpC producing bacteria. To control ESBL/pAmpC prevalence in broilers, transmission within the entire broiler production pyra ...
DOI:
10.1016/j.prevetmed.2018.12.002

9. One step access to oxindole-based β-lactams through Ugi four-center three-component reaction

Author:
Rainoldi, Giulia; Lesma, Giordano; Picozzi, Claudia; Lo Presti, Leonardo; Silvani, Alessandra
Source:
RSC advances 2018 v.8 no.61 pp. 34903-34910
ISSN:
2046-2069
Subject:
beta-lactams,   etc   ; X-radiation; amino acids; antibacterial properties; diastereomers; stereochemistry;     Show all 6 Subjects
Abstract:
... A multicomponent Ugi reaction involving isatin, isocyanide and β-amino acid components has been developed. The reactions proceeded smoothly to give β-lactam-containing 3,3-disubstituted oxindoles in only one step and generally high yields. When chiral, non racemic, β-amino acids were used, products were obtained as enantiomerically pure β-lactams diastereoisomers, whose relative stereochemistry wa ...
DOI:
10.1039/c8ra08165d

10. Comprehensive study towards the desulfonylation/desulfinylation of cis-3-functionalized 3-phenylsulfonyl/sulfinyl-β-lactams to access novel cis-3-monosubstituted-β-lactams

Author:
Kumari, Anu; Bari, S.S.; Modi, Garima; Berry, Shiwani; Khullar, Sadhika; Mandal, Sanjay K.; Bhalla, Aman
Source:
Tetrahedron 2018 v.74 no.33 pp. 4400-4408
ISSN:
0040-4020
Subject:
beta-lactams,   etc   ; X-ray diffraction; chemical reactions; chemical structure; stereochemistry;     Show all 5 Subjects
Abstract:
... An inclusive study towards the stereospecific synthesis of novel cis-3-monosubstituted-β-lactams from cis-3-functionalized 3-phenylsulfonyl/sulfinyl-β-lactams is described. 3-Sulfinyl-β-lactams 5/5ʹ successfully furnished stereospecific cis-3-monosubstituted-β-lactams 6, however 3-sulfonyl-β-lactams 2 failed to give the desulfurized product 6ʹ. The final stereochemical and structural conformations ...
DOI:
10.1016/j.tet.2018.07.008

11. The Unexpected Effects of the Combination of Antibiotics and Immunity

Author:
Burke, Thomas P.
Source:
Cell 2018 v.172 pp. 891-893
ISSN:
0092-8674
Subject:
beta-lactam antibiotics,   etc   ; bacteria; cell walls; immunity; lysozyme;     Show all 5 Subjects
Abstract:
... β-lactam antibiotics and immune enzymes, including lysozyme, kill bacteria by rupturing the cell wall. Curiously, their combination can select for viable, wall-less bacteria. Kawai and colleagues describe the molecular details regarding the emergence of these forms, illustrating a novel and potentially clinically relevant mechanism by which bacteria escape killing by antibiotics. ...
DOI:
10.1016/j.cell.2018.02.003

12. QSRR modeling for the chromatographic retention behavior of some β-lactam antibiotics using forward and firefly variable selection algorithms coupled with multiple linear regression

Author:
Fouad, Marwa A.; Tolba, Enas H.; El-Shal, Manal A.; El Kerdawy, Ahmed M.
Source:
Journal of chromatography 2018 v.1549 pp. 51-62
ISSN:
0021-9673
Subject:
beta-lactam antibiotics; beta-lactams,   etc   ; Lampyridae; acetonitrile; algorithms; buffers; chromatography; experimental design; models; pH; phosphates; regression analysis;     Show all 12 Subjects
Abstract:
... The justified continuous emerging of new β-lactam antibiotics provokes the need for developing suitable analytical methods that accelerate and facilitate their analysis. A face central composite experimental design was adopted using different levels of phosphate buffer pH, acetonitrile percentage at zero time and after 15 min in a gradient program to obtain the optimum chromatographic conditions f ...
DOI:
10.1016/j.chroma.2018.03.042

13. Discovery of anti-mucoviscous activity of rifampicin and its potential as a candidate antivirulence agent against hypervirulent Klebsiella pneumoniae

Author:
Namikawa, Hiroki; Oinuma, Ken-Ichi; Sakiyama, Arata; Tsubouchi, Taishi; Tahara, Yuhei O.; Yamada, Koichi; Niki, Mamiko; Takemoto, Yasuhiko; Miyata, Makoto; Kaneko, Yukihiro; Shuto, Taichi; Kakeya, Hiroshi
Source:
International journal of antimicrobial agents 2019
ISSN:
0924-8579
Subject:
beta-lactams,   etc   ; Klebsiella pneumoniae; aminoglycosides; genes; messenger RNA; microscopy; polysaccharides; quinolones; rifampicin; therapeutics; transcription (genetics); virulence; viscosity;     Show all 13 Subjects
Abstract:
... A recent increase in the incidence of hypervirulent Klebsiella pneumoniae (hvKP) infections, especially those caused by a sublineage of clonal group CG23 (CG23-I), is raising serious health concerns worldwide. The high virulence of hvKP is, at least in part, attributed to the overproduction of capsular polysaccharide (CPS), which is triggered by a positive regulator of capsular polysaccharide synt ...
DOI:
10.1016/j.ijantimicag.2019.05.018

14. Formation of a Reactive, Alkyl Thiolate-Ligated Feᴵᴵᴵ-Superoxo Intermediate Derived from Dioxygen

Author:
Blakely, Maike N.; Dedushko, Maksym A.; Yan Poon, Penny Chaau; Villar-Acevedo, Gloria; Kovacs, Julie A.
Source:
Journal of the American Chemical Society 2019 v.141 no.5 pp. 1867-1870
ISSN:
1520-5126
Subject:
beta-lactam antibiotics,   etc   ; biosynthesis; chemical bonding; dissociation; electrons; energy; enzymes; iron; isotopes; oxygen; spectral analysis; superoxide anion;     Show all 12 Subjects
Abstract:
... Herein, we describe an alkyl thiolate-ligated iron complex that reacts with dioxygen to form an unprecedented example of an iron superoxo (O₂•–) intermediate, [Feᴵᴵᴵ(S₂ᴹᵉ²N₃(Pr,Pr))(O₂)] (4), which is capable of cleaving strong C–H bonds. A cysteinate-ligated iron superoxo intermediate is proposed to play a key role in the biosynthesis of β-lactam antibiotics by isopenicillin N-synthase (IPNS). Su ...
DOI:
10.1021/jacs.8b12670

15. Electroporation of germinated conidia and young mycelium as an efficient transformation system for Acremonium chrysogenum

Author:
Cruz-Ramón, Jessica; Fernández, Francisco J.; Mejía, Armando; Fierro, Francisco
Source:
Folia microbiologica 2019 v.64 no.1 pp. 33-39
ISSN:
0015-5632
Subject:
beta-lactam antibiotics,   etc   ; Acremonium chrysogenum; capacitance; cell viability; conidia; electroporation; fungi; genetic transformation; mutants; mycelium; protoplasts; sporulation;     Show all 12 Subjects
Abstract:
... Three different transformation strategies were tested and compared in an attempt to facilitate and improve the genetic transformation of Acremonium chrysogenum, the exclusive producer of the pharmaceutically relevant β-lactam antibiotic cephalosporin C. We investigated the use of high-voltage electric pulse to transform germinated conidia and young mycelium and compared these procedures with tradi ...
DOI:
10.1007/s12223-018-0625-0

16. Stereochemistry and reactivity of the HPA-imine Mannich intermediate

Author:
Polyak, Daniel; Phung, Ngan; Liu, Jian; Barrows, Robert; Emge, Thomas J.; Knapp, Spencer
Source:
Tetrahedron letters 2017 v.58 pp. 3879-3883
ISSN:
0040-4039
Subject:
beta-lactams,   etc   ; chemical reactions; isomers; stereochemistry; temperature;     Show all 5 Subjects
Abstract:
... Homophthalic anhydride (HPA) typically reacts rapidly with benzalimines to afford the formal [4+2] adduct, a 1,2,3,4-tetrahydroisoquinolin-1-one-4-carboxylic acid. The stereochemical outcome of this reaction is consistent with an open transition state comprising an iminium species and enolized HPA, leading to a short-lived amino-anhydride intermediate. In the case of N-tert-butylbenzalimine, this ...
DOI:
10.1016/j.tetlet.2017.08.070
PubMed:
29276314
PubMed Central:
PMC5737782

17. Pyrolysis of 1-alkylazetidinone derivatives: A versatile route toward electron-rich alkenes, C-1 allylation and/or homologation of aldehydes

Author:
Habib, Osama M.; Ibrahim, Yehia A.; Al-Awadi, Nouria A.
Source:
Journal of analytical and applied pyrolysis 2017 v.125 pp. 162-168
ISSN:
0165-2370
Subject:
beta-lactams,   etc   ; aldehydes; alkenes; energy; pyrolysis; stereochemistry;     Show all 6 Subjects
Abstract:
... 1-Alkyl-3-phenoxy-β-lactams have been synthesized by the standard Staudinger ketene-imine [2+2] cycloaddition. The corresponding β-thiolactams have readily been obtained in good yields by thiation with Lawesson's reagent. Static pyrolysis (STP) as well as FVP of these β-lactams and β-thiolactams led essentially to stereoselective synthesis of Z-alkenes. The 3-allyloxy-1-alkyl-β-lactams and β-thiol ...
DOI:
10.1016/j.jaap.2017.03.023

18. A highly efficient stereoselective synthesis of β-lactams

Author:
Goyal, Sandeep; Pal, Anang; Chouhan, Mangilal; Gangar, Mukesh; Sarak, Sharad; Nair, Vipin A.
Source:
Tetrahedron letters 2017 v.58 pp. 346-348
ISSN:
0040-4039
Subject:
beta-lactams,   etc   ; chemical reactions; chemical structure; stereochemistry;     Show all 4 Subjects
Abstract:
... An efficient strategy for a one-pot, single step synthesis of β-lactams employing an imidazolidinone based chiral auxiliary with various aldimines via asymmetric Mannich-type reaction has been described. ...
DOI:
10.1016/j.tetlet.2016.12.033

19. Stereocontrolled Synthesis of β-Lactams within [2]Rotaxanes: Showcasing the Chemical Consequences of the Mechanical Bond

Author:
Martinez-Cuezva, Alberto; Lopez-Leonardo, Carmen; Bautista, Delia; Alajarin, Mateo; Berna, Jose
Source:
Journal of the American Chemical Society 2016 v.138 no.28 pp. 8726-8729
ISSN:
1520-5126
Subject:
beta-lactams,   etc   ; reaction mechanisms; synthesis;     Show all 3 Subjects
Abstract:
... The intramolecular cyclization of N-benzylfumaramide [2]rotaxanes is described. The mechanical bond of these substrates activates this transformation to proceed in high yields and in a regio- and diastereoselective manner, giving interlocked 3,4-disubstituted trans-azetidin-2-ones. This activation effect markedly differs from the more common shielding protection of threaded functions by the macroc ...
DOI:
10.1021/jacs.6b05581

20. Palladium-Catalyzed Intramolecular Insertion of Alkenes into the Carbon–Nitrogen Bond of β-Lactams

Author:
Yada, Akira; Okajima, Satoshi; Murakami, Masahiro
Source:
Journal of the American Chemical Society 2015 v.137 no.27 pp. 8708-8711
ISSN:
1520-5126
Subject:
beta-lactams,   etc   ; alkenes; palladium;     Show all 3 Subjects
Abstract:
... The carbon–nitrogen bond of β-lactams is cleaved by palladium(0), and an alkene is intramolecularly inserted therein. The following reductive elimination produces nitrogen-containing benzo-fused tricycles in good to high yields. ...
DOI:
10.1021/jacs.5b05308