Nuclear analogs of β-lactam antibiotics. II. Synthesis of O-2-isocephems

1977 ◽  
Vol 55 (3) ◽  
pp. 484-507 ◽  
Author(s):  
Terrence W. Doyle ◽  
Bernard Belleau ◽  
Bing-Yu Luh ◽  
Terry Thomas Conway ◽  
Marcel Menard ◽  
...  

The preparation by total synthesis of a new class of β-lactam antibiotics is reported. Conversion of alcohol 1b to its mesylate 9b followed by hydrolysis of the acetal to the enol 1b and base-catalyzed ring closure gave benzyl 7- β-azido-Δ3-O-2-isocephem-4-carboxylate 8b. Similarly prepared were the 3 -methyl, 3 -benzyl, and 3 -phenethyl analogs (32b–d). Reduction of the azides followed by coupling of the resultant amines with phenoxyacetic acid and removal of the benzyl groups by hydrogenolysis gave the acids 35a–e which exhibited high antibacterial activity. The structural assignments to the O-2-isocephems which were made on the basis of their spectral characteristics (ir, uv, and nmr) are discussed.

2018 ◽  
Vol 61 (17) ◽  
pp. 7814-7826 ◽  
Author(s):  
Matthieu Sarciaux ◽  
Lucile Pantel ◽  
Camille Midrier ◽  
Marine Serri ◽  
Cristelle Gerber ◽  
...  

Author(s):  
Sarella Prakash Nathaniel Kumar ◽  
Kanthal L.K. ◽  
Durga S ◽  
Achutha Rama Raju D ◽  
Satyavati K

Several herbs are traditionally used in the treatment of a variety of ailments particularly in the rural areas, where herbal medicine is mainly the source of health care system. Many of these herbs havenot been assessed for safety or toxicity to tissue or organs of the mammalian recipients. An attempt is made to prove the efficacy of Sida cordifolia Linn., (a traditional medicinal plant chosen on the basis of ethnomedical knowledge) for its Cardiotonic, Antibacterial and Anthelmintic activities. Sida cordofolia Linn., is used traditionally, inter alia, in the treatment of various infections, asthma, diarrhoea, heart and stomach disorders. Cardiotonicactivity is performed using isolated Frog Heart Perfusion Technique. Antibacterial activity of the whole plant extracts were assessed by Agar well diffusion method against the strains of Bacillus subtilis, Escherichia coli, and Staphylococcus aureus. Anthelmintic activity was studied against Pheretima posthuma. Phytochemical screening of powdered plant material revealed thepresence of some secondary metabolites such as alkaloids, saponins, tannins, glycosides and flavonoids. Results indicated that methanol, chloroform, aqueous extracts have significant cardiotonic activity but less than standard drugs. Methanol and Aqueous extracts showed high antibacterial activity and anthelmintic activity than the standard drugs. In a nutshell, we can conclude that the methanol and aqueous fractions of Sida cordifolia Linn., had a profound antibacterial and anthelmintic effect eventhough it possessed very significant cardiotonic activity. This validates its continuous usage in ethnomedicine. This plant could be developed into cheap, safe and culturally acceptable standardized herbal products and may serve as asource of new molecules for broad-spectrum antimicrobial and anthelmintic agent.


2020 ◽  
Vol 17 (5) ◽  
pp. 716-724
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Vladimir A. Aladinskiy ◽  
...  

Background: The key issue in the development of novel antimicrobials is a rapid expansion of new bacterial strains resistant to current antibiotics. Indeed, World Health Organization has reported that bacteria commonly causing infections in hospitals and in the community, e.g. E. Coli, K. pneumoniae and S. aureus, have high resistance vs the last generations of cephalosporins, carbapenems and fluoroquinolones. During the past decades, only few successful efforts to develop and launch new antibacterial medications have been performed. This study aims to identify new class of antibacterial agents using novel high-throughput screening technique. Methods: We have designed library containing 125K compounds not similar in structure (Tanimoto coeff.< 0.7) to that published previously as antibiotics. The HTS platform based on double reporter system pDualrep2 was used to distinguish between molecules able to block translational machinery or induce SOS-response in a model E. coli system. MICs for most active chemicals in LB and M9 medium were determined using broth microdilution assay. Results: In an attempt to discover novel classes of antibacterials, we performed HTS of a large-scale small molecule library using our unique screening platform. This approach permitted us to quickly and robustly evaluate a lot of compounds as well as to determine the mechanism of action in the case of compounds being either translational machinery inhibitors or DNA-damaging agents/replication blockers. HTS has resulted in several new structural classes of molecules exhibiting an attractive antibacterial activity. Herein, we report as promising antibacterials. Two most active compounds from this series showed MIC value of 1.2 (5) and 1.8 μg/mL (6) and good selectivity index. Compound 6 caused RFP induction and low SOS response. In vitro luciferase assay has revealed that it is able to slightly inhibit protein biosynthesis. Compound 5 was tested on several archival strains and exhibited slight activity against gram-negative bacteria and outstanding activity against S. aureus. The key structural requirements for antibacterial potency were also explored. We found, that the unsubstituted carboxylic group is crucial for antibacterial activity as well as the presence of bulky hydrophobic substituents at phenyl fragment. Conclusion: The obtained results provide a solid background for further characterization of the 5'- (carbonylamino)-2,3'-bithiophene-4'-carboxylate derivatives discussed herein as new class of antibacterials and their optimization campaign.


2019 ◽  
Vol 16 (3) ◽  
pp. 245-248
Author(s):  
Hummera Rafique ◽  
Aamer Saeed ◽  
Ehsan Ullah Mughal ◽  
Muhammad Naveed Zafar ◽  
Amara Mumtaz ◽  
...  

Background: (±)-6,8-Dihydroxy-3-undecyl-3,4-dihydroisochromen-1-one is one of the structural analog of several substituted undecylisocoumarins isolated from Ononis natrix (Fabaceae), has been successfully synthesized by direct condensation of homopthalic acid (1) with undecanoyl chloride yields isochromen-1-one (2). Methods: Alkaline hydrolysis of (2) gave the corresponding keto-acid (3), which is then reduced to hydroxy acid (4) then its cyclodehydration was carried out with acetic anhydride to afford 3,4- dihydroisochromen-1-one (5). Followed by demethylation step, the synthesis of target 6,8- dihydroxy-7-methyl-3-undecyl-3,4-dihydroisocoumarin (6) was achieved. Results: In vitro antibacterial screening of all the synthesized compounds were carried out against ten bacterial strains by agar well diffusion method. Conclusion: Newly synthesized molecules exhibited moderate antibacterial activity and maximum inhibition was observed against Bacillus subtilus and Salmonella paratyphi.


2020 ◽  
Vol 17 (8) ◽  
pp. 991-1041
Author(s):  
Divya Utreja ◽  
Jagdish Kaur ◽  
Komalpreet Kaur ◽  
Palak Jain

Triazine, one of the nitrogen containing heterocyclic compounds has attracted the considerable interest of researchers due to the vast array of biological properties such as anti-viral, antitumor, anti-convulsant, analgesic, antioxidant, anti-depressant, herbicidal, insecticidal, fungicidal, antibacterial and anti-inflammatory activities offered by it. Various antibacterial agents have been synthesized by researchers to curb bacterial diseases but due to rapid development in drug resistance, tolerance and side effects, there had always been a need for the synthesis of a new class of antibacterial agents that would exhibit improved pharmacological action. Therefore, this review mainly focuses on the various methods for the synthesis of triazine derivatives and their antibacterial activity.


2021 ◽  
pp. 152808372110117
Author(s):  
Sommai Pivsa-Art ◽  
Komson Sunyikhan ◽  
Weraporn Pivsa-Art

Recycled poly(ethylene terephthalate) (RPET) multifilament yarns are used in carpet manufacturing as a way to reduce plastic waste. The conventional RPET carpet is however susceptible to bacterial accumulation. As a result, this research experimentally doped RPET with nano-structure titanium dioxide (nano-TiO2) to produce RPET/nano-TiO2 bicomponent multifilament yarns with antibacterial property. The experimental multifilament yarn structure consisted of two parts: neat RPET core and RPET/nano-TiO2 shell. The nano-TiO2 content in the shell was varied between 1 and 3 wt% and the core/shell (C/S) ratios between 90/10, 70/30, and 50/50 w/w. The effects of C/S ratio and nano-TiO2 content on the mechanical and antibacterial properties of bicomponent multifilament yarns were determined. The experimental results indicated that the C/S ratio had no effect on the tenacity and elongation at break. Meanwhile, the tenacity and elongation at break of bicomponent fibers increased with nano-TiO2 content in the shell. The TiO2-doped RPET bicomponent yarns effectively inhibited the growth of Escherichia coli and Staphylococcus aureus. The 90/10 bicomponent multifilament fiber with 3 wt% TiO2 achieved the highest antibacterial activity. The very high antibacterial activity was attributable to greater deposition of nano-TiO2 particles near and on the shell surface.


2010 ◽  
Vol 65 (4) ◽  
pp. 445-451 ◽  
Author(s):  
René Csuk ◽  
Erik Prell ◽  
Stefan Reißmann ◽  
Claudia Korb

A straightforward chiral pool synthesis for the first fluorinated calystegin is described. Key steps of this synthesis include an ultrasound-assisted Zn-mediated tandem ring opening reaction followed by a Grubbs’ catalyst-mediated ring closure metathesis reaction. The target compound is a selective and competitive inhibitor for a β -glycosidase.


Synthesis ◽  
2018 ◽  
Vol 50 (23) ◽  
pp. 4569-4576
Author(s):  
Tian Jin ◽  
Lu Zhao ◽  
Zhe-Bin Zheng ◽  
Xiao Liu ◽  
Liang Sun ◽  
...  

Clavaminols are a new class of long-chain 2-amino-3-­alkanols that mostly contain 2R,3S-configurations. Owing to their interesting molecular architectures and promising activities, they have ­become popular targets for synthetic organic chemists. In this review, we highlight 12 total syntheses of clavaminols from different research groups during the period 2009 to 2018.1 Introduction2 Synthetic Approaches toward Clavaminols2.1 Total Synthesis by Chemla and Colleagues (2009)2.2 Total Synthesis by Greck and Colleagues (2010)2.3 Total Synthesis by Sutherland and Zaed (2011)2.4 Total Synthesis by Huang and Colleagues (2011)2.5 Total Synthesis by Kotora and Colleagues (2012)2.6 Total Synthesis by Kumar and Colleagues (2013)2.7 Total Synthesis by Prabhavathi Devi and Colleagues (2013 and 2016)2.8 Total Synthesis by Sarabia and Colleagues (2014)2.9 Total Synthesis by Mohapatra and Colleagues (2016)2.10 Total Synthesis by Lu and Colleagues (2016)2.11 Total Synthesis by Jin and Colleagues (2017)2.12 Total Synthesis by Kumar Pandey and Colleagues (2018)3 Conclusion


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