scholarly journals Synthesis and Antimicrobial Evaluation of Novel Pyrazolopyrimidines Incorporated with Mono- and Diphenylsulfonyl Groups

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 4009 ◽  
Author(s):  
Alsaedi ◽  
Farghaly ◽  
Shaaban

A novel series of pyrazolo[1,5-a]pyrimidine ring systems containing phenylsulfonyl moiety have been synthesized via the reaction of 2-(phenylsulfonyl)-1-(4-(phenylsulfonyl) phenyl)ethan-1-one, 2-benzenesulfonyl-1-(4-benzenesulfonyl-phenyl)-3-dimethylamino-propenone and 3-(dimethylamino)-1-(4-(phenylsulfonyl)phenyl)prop-2-en-1-one each with various substituted aminoazopyrazole derivatives in one pot reaction strategy. The proposed structure as well as the mechanism of their reactions were discussed and proved with all possible spectral data. The results of antimicrobial activities of the new sulfone derivatives revealed that several derivatives showed activity exceeding the activity of reference drug. Contrary to expectations, we found that derivatives containing one sulfone group are more effective against all bacteria and fungi used than those contain two sulfone groups.

2019 ◽  
Vol 16 (5) ◽  
pp. 512-521 ◽  
Author(s):  
Nidhi Rani ◽  
Randhir Singh

Background: A series of novel substituted 2-mercaptoimidazoles was synthesised efficiently and in high yields using one-pot synthesis from m-hydroxyacetophenones. Methods: The structures of the newly synthesized compounds were established, their molecular activity was investigated against some bacteria and fungi were further validated using molecular docking study. Results: Reaction of o-hydroxyphenacylbromide (2) with substituted aniline and KSCN, in the presence of catalyst p-toluene sulfonic acid afforded 4(a-r) in good yield. The structure of compounds (4a-r) was confirmed by IR, NMR and MS. Conclusion: The compounds exhibited excellent antimicrobial potency against the tested microorganism.


2009 ◽  
Vol 6 (3) ◽  
pp. 866-870
Author(s):  
CH. Sridevi ◽  
K. Balaji ◽  
A. Naidu ◽  
R. Sudhakaran

2,3-Diphenyl quinoxaline(SI)was fused with 2-amino benzothiazoles(SII)by a methylene bridge, which was then allowed for acetylation. The acetylated product (SIV) was made to react with different aromatic aldehydes to give chalcones(SV1-SV5). Chalcones refluxed with substituted acid hydrazides to afford different phenyl pyrazolo benzothiazolo quinoxaline derivatives(SVI1-SVI15). The structure of chalcones and phenyl pyrazolo benzothiazolo quinoxaline derivatives were confirmed by M.P, TLC and spectral data. All the synthesized compounds were screened for their antimicrobial activities.


2007 ◽  
Vol 72 (4) ◽  
pp. 321-329 ◽  
Author(s):  
Sohel Mostahar ◽  
Sayed Alam ◽  
Azizul Islam

Two new 2'-oxygenated flavones have been synthesized via chalcone precursors and the biocidal activity of these two flavones, along with the corresponding chalcones against microbes (bacteria and fungi) and brine shrimp nauplii were investigated. Both the flavones (compounds 6 and 7) and their corresponding chalcones (compounds 4 and 5) showed good activity against all the tested bacterial and fungal strains. The LC50 values of compounds 4-7 were found to be 2.31, 0.94, 1.39 and 0.58 ?gmL -1, respectively. The synthesized compounds were characterized using UV-Vis, IR, 1H-NMR and 13C-NMR spectral data, together with elemental analysis. .


Drug Research ◽  
2021 ◽  
Author(s):  
Preeti Sharma ◽  
Varun Kumar Singh ◽  
Gajendra Kumar

AbstractSchiff base ligand (E)-5-methyl-3-(1-(4-nitrophenylimino)ethyl)-1H-indol-2-amine was synthesized by the condensation of 1-(2-amino-5-methyl-1H-indol-3-yl)ethanone and 4-nitrobenzenamine in methanol at 70 oC. The prepared Schiff base ligand doped with Cr(III), Mn(III) and Fe(III) ion, respectively and it is denoted as [M(C34H32N8O4)X]X2. The complexes have been characterized with the help of elemental analysis, conductance measurements, magnetic measurements and their structural configuration have been determined by various spectroscopic (electronic, IR, 1H NMR, 13C NMR, GCMS) techniques. Electronic and magnetic moments of the complexes indicate that the geometry of the metal center was five coordinate square pyramidal. These metal complexes were also tested for their antimicrobial activities to assess their inhibiting potential against Staphylococcus aureus, Bacillus subtilis (positive bacteria) and Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi (negative bacteria) and fungi Rizoctonia sp., Aspergillus sp., Penicillium sp. [Cr(C34H32N8O4)OAc](OAc)2 shows best antimicrobial activity against all the pathogens.


INDIAN DRUGS ◽  
2018 ◽  
Vol 55 (09) ◽  
pp. 15-23
Author(s):  
K. Govindarao ◽  
◽  
N. Srinivasan ◽  
R. Suresh ◽  
K Ravi Shankar

The present work describes the synthesis of a series of quinoline based 4-thiazolidinone and 2-azetidinone derivatives from Schiff bases obtained from the condensation of 2-chloro-3-formylquinoline and 3-4-aminoacetophenones. Quinoline based 4-thiazolidinone and 2-azetidinone derivatives have been prepared by the reaction of various substituted Schiff base with thioglycholic acid and chloroacetyl chloride, respectively. The intermediate Schiff bases were synthesized by the condensation of different quinoline aldehydes with amino acetophenones. The starting compound i.e aldehyde was synthesized through Vilsmeier reaction from respective acetanilides. The synthesized compounds were characterized by their physical and spectral data. The synthesized compounds were screened for their antibacterial and antifungal activities by using cup plate method against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, 25, 50, 100 μg/mL concentration using ciprofloxacin as reference standard drug and Aspergillus niger, Candida albicans as same concentration using clotrimazole as reference drug, respectively. The spectral data of synthesized compounds of (3a-f), (4a-e) and (5a-f) were characterized by ES Mass, 1H-NMR, IR spectrophotometric methods. The antimicrobial results revealed that the quinoline based Schiff bases, azitidinone and thiazolodinones analogues showed good activity towards Gram (+) bacteria as compared to ciprofloxacin. These compounds showed decent activity against Gram (-) bacteria.


2011 ◽  
Vol 8 (3) ◽  
pp. 1022-1029 ◽  
Author(s):  
A. M. Sridhara ◽  
K. R. Venugopala Reddy ◽  
J. Keshavayya ◽  
D. S. Ambika ◽  
Sanathkumar Goud ◽  
...  

A series of new 3-isoxazoline substituted phthalazine methylsulfonyl-oxadiazoles were prepared from methyl 2-(4-oxo-3,4-dihydrophthalazin-1-yl) acetate. The structure of synthesized compounds were characterized by spectral data and screened for their antimicrobial activities against various bacteria and fungi strains. Several of these compounds showed antimicrobial activity.


2019 ◽  
Vol 15 (1) ◽  
pp. 63-70
Author(s):  
Shiv Dev Singh ◽  
Arvind Kumar ◽  
Firoz Babar ◽  
Neetu Sachan ◽  
Arun Kumar Sharma

Background: Thienopyrimidines are the bioisoster of quinazoline and unlike quinazoline exist in three isomeric forms corresponding to the three possible types annulation of thiophene to the pyrimidine ring viz thieno[2,3-d] pyrimidine, thieno[3,2-d] pyrimidine and thieno[3,4-d]pyrimidine. Heterocyclic containing the thienopyrimidinone moiety exhibits various pronounced activities such as anti-hypertensive, analgesic and anti-inflammatory, antiviral, platelet aggregation inhibitory, antiprotozoal bronchodilatory, phosphodiesterase inhibitory, antihistaminic, antipsychotic and antimicrobial activity. Objective: Synthesis of novel 3(N,N-dialkylamino)alkyl/phenyl substituted thieno[2,3-d]pyrimidinones as H1-anti-histaminic and antimicrobial agents. Methods: A series of 3-[(N,N-dialkylamino)alkyl/phenyl]-2-(1H)thioxo-5,6,7,8-tetrahydrobenzo(b) thieno(2,3-d)pyrimidine-4(3H)-ones[4a-d], their oxo analogous [5a-d] and 3-[(N,N-dialkylamino)alkyl]- 2-chlorophenyl-5,6,7,8-tetrahydrobenzo(b)thieno(2,3-d)pyrimidine- 4 (3H)-ones[6a-d]derivative were synthesized from 2-amino-4,5,6,7-tetrahydrobenzo(b)thiophene-3-carboxylic acid by nucleophilic substitution of different N,N-dialkyl alkylene/phenylene diamines on activated 3-acylchloride moiety followed by cyclocondensation with carbon disulfide and ethanolic potassium hydroxide to get [4a-d] and in second reaction by condensation with 4-chlorobenzoyl chloride to get [6a-d] by single pot novel innovative route. The oxo analogous [5a-d] were prepared by treating derivatives [4a-d] with potassium permagnate in ethanolic KOH. The synthesized compound were evaluated for H1-antihistaminic and antimicrobial activities. Results: All synthesized compounds exhibited significant H1-antihistaminic activity by in vitro and in vivo screening methods and data were verified analytically and statistically. The compound 4a, 4b, 5a and 5b showed significant H1-antihistaminiic activity than the reference standard chlorpheniramine maleate. The compound 6d, 6c, 5c and 4c exhibited significant antimicrobial activity.


2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Junpeng Li ◽  
Shuping Hu ◽  
Wei Jian ◽  
Chengjian Xie ◽  
Xingyong Yang

AbstractAntimicrobial peptides (AMPs) are a class of short, usually positively charged polypeptides that exist in humans, animals, and plants. Considering the increasing number of drug-resistant pathogens, the antimicrobial activity of AMPs has attracted much attention. AMPs with broad-spectrum antimicrobial activity against many gram-positive bacteria, gram-negative bacteria, and fungi are an important defensive barrier against pathogens for many organisms. With continuing research, many other physiological functions of plant AMPs have been found in addition to their antimicrobial roles, such as regulating plant growth and development and treating many diseases with high efficacy. The potential applicability of plant AMPs in agricultural production, as food additives and disease treatments, has garnered much interest. This review focuses on the types of plant AMPs, their mechanisms of action, the parameters affecting the antimicrobial activities of AMPs, and their potential applications in agricultural production, the food industry, breeding industry, and medical field.


Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 137
Author(s):  
Xinzhen Fan ◽  
L’Hocine Yahia ◽  
Edward Sacher

Microbes, including bacteria and fungi, easily form stable biofilms on many surfaces. Such biofilms have high resistance to antibiotics, and cause nosocomial and postoperative infections. The antimicrobial and antiviral behaviors of Ag and Cu nanoparticles (NPs) are well known, and possible mechanisms for their actions, such as released ions, reactive oxygen species (ROS), contact killing, the immunostimulatory effect, and others have been proposed. Ag and Cu NPs, and their derivative NPs, have different antimicrobial capacities and cytotoxicities. Factors, such as size, shape and surface treatment, influence their antimicrobial activities. The biomedical application of antimicrobial Ag and Cu NPs involves coating onto substrates, including textiles, polymers, ceramics, and metals. Because Ag and Cu are immiscible, synthetic AgCu nanoalloys have different microstructures, which impact their antimicrobial effects. When mixed, the combination of Ag and Cu NPs act synergistically, offering substantially enhanced antimicrobial behavior. However, when alloyed in Ag–Cu NPs, the antimicrobial behavior is even more enhanced. The reason for this enhancement is unclear. Here, we discuss these results and the possible behavior mechanisms that underlie them.


2021 ◽  
Vol 9 (1) ◽  
pp. 171
Author(s):  
Yitayal S. Anteneh ◽  
Qi Yang ◽  
Melissa H. Brown ◽  
Christopher M. M. Franco

The misuse and overuse of antibiotics have led to the emergence of multidrug-resistant microorganisms, which decreases the chance of treating those infected with existing antibiotics. This resistance calls for the search of new antimicrobials from prolific producers of novel natural products including marine sponges. Many of the novel active compounds reported from sponges have originated from their microbial symbionts. Therefore, this study aims to screen for bioactive metabolites from bacteria isolated from sponges. Twelve sponge samples were collected from South Australian marine environments and grown on seven isolation media under four incubation conditions; a total of 1234 bacterial isolates were obtained. Of these, 169 bacteria were tested in media optimized for production of antimicrobial metabolites and screened against eleven human pathogens. Seventy bacteria were found to be active against at least one test bacterial or fungal pathogen, while 37% of the tested bacteria showed activity against Staphylococcus aureus including methicillin-resistant strains and antifungal activity was produced by 21% the isolates. A potential novel active compound was purified possessing inhibitory activity against S. aureus. Using 16S rRNA, the strain was identified as Streptomyces sp. Our study highlights that the marine sponges of South Australia are a rich source of abundant and diverse bacteria producing metabolites with antimicrobial activities against human pathogenic bacteria and fungi.


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