scholarly journals Synthesis and Antimicrobial Activities of 1,2,4-Triazole and 1,3,4-Thiadiazole Derivatives of 5-Amino-2-Hydroxybenzoic Acid

2008 ◽  
Vol 5 (4) ◽  
pp. 963-968 ◽  
Author(s):  
Sabir Hussain ◽  
Jyoti Sharma ◽  
Mohd Amir

Various 4-amino-2-[4-(4-substituted phenyl)-5-sulfanyl-4H-1,2,4-triazol-3-yl] phenol (4a-c), 4-amino-2-{4-amino-5-[(4-substituted phenyl)amino]-4H-1,2,4-triazol-3-yl} phenol (5a-c) and 4-amino-2-{5-[(4-substituted phenyl)amino]-1,3,4-thiadiazole-2-yl} phenol (6a-g) were synthesized and evaluated for their antibacterial and antifungal activity. The compounds showed significant antibacterial activity againstS. aureus(gram-positive) andE.coli(gram-negative) bacteria and antifungal activity againstA. nigerfungi using cup plate technique

2020 ◽  
Vol 16 (4) ◽  
pp. 481-488
Author(s):  
Heli Sanghvi ◽  
Satyendra Mishra

Background: Curcumin, one of the most important pharmacologically significant natural products, has gained significant consideration among scientists for decades since its multipharmacological activities. 1, 3-Dicarbonyl moiety of curcumin was found to be accountable for the rapid degradation of curcumin molecule. The aim of present work is to replace 1, 3-dicarbonyl moiety of curcumin by pyrazole and phenylpyrazole derivatives with a view to improving its stability and to investigate the role of substitution in N-phenylpyrazole curcumin on its antibacterial activity against both Gram-positive as well as Gram-negative bacteria. Methods: Pyrazole derivatives of curcumin were prepared by heating curcumin with phenyhydrazine/ substituted phenyhydrazine derivatives in AcOH. The residue was purified by silica gel column chromatography. Structures of purified compounds were confirmed by 1H NMR and Mass spectroscopy. The synthesized compounds were evaluated for their antibacterial activity by the microdilution broth susceptibility test method against gram positive (S. aureus) and gram negative (E. coli). Results: Effects of substitution in N-phenylpyrazole curcumin derivatives against S. aureus and E. coli were studied. The most active N-(3-Nitrophenylpyrazole) curcumin (12) exhibits twenty-fold more potency against S. aureus (MIC: 10μg/mL)) and N-(2-Fluoroophenylpyrazole) curcumin (5) fivefold more potency against E. coli (MIC; 50 μg/mL) than N-phenylpyrazole curcumin (4). Whereas, a remarkable decline in anti-bacterial activity against S. aureus and E. coli was observed when electron donating groups were incorporated in N-phenylpyrazole curcumin (4). Comparative studies of synthesized compounds suggest the effects of electron withdrawing and electron donating groups on unsubstituted phenylpyrazole curcumin (4). Conclusion: The structure-activity relationship (SAR) results indicated that the electron withdrawing and electron donating at N-phenylpyrazole curcumin played key roles for their bacterial inhibitory effects. The results of the antibacterial evaluation showed that the synthesized pyrazole derivatives of curcumin displayed moderate to very high activity in S. aureus. In conclusion, the series of novel curcumin derivatives were designed, synthesized and tested for their antibacterial activities against S. aureus and E. coli. Among them, N-(3-Nitrophenylpyrazole curcumin; 12) was most active against S. aureus (Gram-positive) and N-(2-Fluoroophenylpyrazole) curcumin (5) against E. coli (Gram-negative) bacteria.


2020 ◽  
Vol 8 (6) ◽  
pp. 179-187
Author(s):  
Titik Taufikurohmah ◽  
Tasha Anandya Tantyani

This Research on the antibacterial and antifungal activity of nanosilver against Neisseria gonorrhoeae and Candida albincas fungi has been carried out. The purpose of this study was to determine antibacterial activity of nanosilver against Neisseria gonorrhoeae and antifungal activity against Candida albincas. Synthesis Nanosilver uses bottom up method and characterized using UV-Vis Spectrophotometer. Nanosliver concentrations used were 30, 40, 50, and 60 ppm. Antibacterial and antifungal activity tests using disk diffusion method. Observations obtained in form of the presence or absence of clear zones formed around paper discs indicate the inhibition of nanosilver on microbial growth. The results of testing the antifungal activity of Candida albicans on nanosilver with concentrations of 30, 40, 50 and 60 ppm resulted in clear zones of 9.73 nm, 11.46 nm, 11.93 nm, and 13 nm with fungal inhibition response categories is medium and strong. The results antibacterial activity test of Neisseria gonorrhoeae on nanosilver with concentrations of 30, 40, 50 and 60 ppm did not show any clear zone around the disc, it showed that nanosilver in this study did not have antibacterial activity against Neisseria gonorrhoeae.


2021 ◽  
Vol 3 (1) ◽  
pp. 1-5
Author(s):  
Poonam Sethi ◽  
Nandhagopal Karmegam

ABSTRACT Artabotrys odoratissimus R.Br.  (Annonaceae) a medium sizes shrub with hooks, sweet smelling flowers and aggregate fruits, was tested for activity against gram negative bacteria. The fruit of the experimental plant was extracted with water, methanol and toluene: methanol (2:1 v/v). Artabotrys fruits showed good antibacterial activity and produced zone of inhibition of 32mm. The methanolic extract of the fruit showed maximum zone of inhibition at 300 ?g/ml against Pseudomonas fluorescens. The present study clearly indicates that A. odoratissimus had a profound antimicrobial   activity and it may be useful in the treatment of various infectious caused by bacteria. Keywords: Artabotrys, Gram Negative Bacteria, Pseudomonas, Zone Of Inhibition


1970 ◽  
Vol 18 ◽  
pp. 128-133 ◽  
Author(s):  
MTH Molla ◽  
MS Ahsan ◽  
MT Alam ◽  
ME Haque

Context: Development of resistance in human pathogens against conventional antibiotic necessitates searching indigenous medicinal plants having antibacterial property. Seven medicinal plants used actively in folklore, ayurvedic and traditional system of medicine were selected for the evaluation of their antimicrobial activity for this study.   Objectives: Evaluation of the effectiveness of some medicinal plant extracts against four Gram-positive and five Gram-negative bacteria.  Materials and Methods: The antibacterial activity of the crude ethanolic extracts obtained from the leaves of seven medicinal plants; viz., Andrographis paniculata, Catharanthus roseus, Adhatoda vasica, Vitex vegundo, Aloe vera, Flacortia ramontchi and Nyctanthes arbortristis were tested against nine bacteria at concentrations of 300-, 400- and 500 μg/ml. Standard antibiotic disc kanamycin (30μg/ml) was used for comparison. The minimum inhibitory concentration (MIC) of ethanolic extracts of the leaves of these medicinal plants were determined by testing the extracts on four Gram-positive and five Gram-negative bacteria by serial tube dilution method.   Results: All the extracts have notable antimicrobial activities against the test organisms. The ethanolic extracts of the leaves showed the highest antimicrobial activities against Bacillus megaterium and Shigella dysenteriae for An. paniculata, Ad. vasica and Al. vera; Bacillus subtilis and Salmonella typhi for C. roseus and N. arbortristis; Staphylociccus aureus and Salmonella typhi for V. vegundo; and Bacillus subtilis and Shigella sonnei for F. ramontchi respectively. The extract of the plants had MIC values ranging from 32 to 128 mg/ml. All plant extracts showed no MIC against Shigella shiga and against Sarcina lutea only C. roseus showed MIC 128 mg/ml.   Conclusion: The results revealed that the ethanolic extracts of the plants under present investigation have notable antimicrobial activities.   Keywords: medicinal plants; antimicrobial screening; MIC; bacteria. DOI: http://dx.doi.org/10.3329/jbs.v18i0.8788 JBS 2010; 18(0): 128-133


2000 ◽  
Vol 68 (4) ◽  
pp. 333-341 ◽  
Author(s):  
Jerzy Cieplik ◽  
Janusz Pluta ◽  
Olaf Gubrynowicz

The paper presents the synthesis of 5-substituted pyrimidine sulphonamides as well as the results of studies on the antibacterial and antifungal activity of obtained derivatives.


2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Mouna Bouzid ◽  
Raed Abdennabi ◽  
Mohamed Damak ◽  
Majed Kammoun

This paper describes the synthesis of a series of dihydroisoquinoline nitrones by isomerization of the corresponding oxaziridines. Nitrones4a–cwere obtained in excellent yields and high purity by a simple and effective method from the isomerization of oxaziridines. The synthesized compounds were also evaluated for their antibacterial activity against Gram-positive and Gram-negative bacteria and fungus.


2017 ◽  
Vol 9 (2) ◽  
pp. 45 ◽  
Author(s):  
Bahareh Behmaram ◽  
Naser Foroughifar ◽  
Neda Foroughifar ◽  
Sara Hallajian

The synthesis of some 1,3-diazoles and thiazoles was realized in different conditions:a) In the presence of PTSA or sulfuric acid as catalyst we obtained only diazole products(4a-d).b) In basic medium such as DABCO or sodium hydroxide and ionic liquid afforded thiazoles.c) Both products, diazoles and thiazoles were collected when using methanol as catalyst and solvent.All structures were confirmed by IR, 1H NMR and 13C NMR spectroscopy. The antibacterial activity of some synthesized compounds was investigated against Escherichia Coli (ATCC: 25922) and Serratia marcescens (ATCC: 13880) as gram negative bacteria, Bacillus sabtilis (ATCC: 6633) and Staphylococcus aureus (ATCC: 6338) as gram positive bacteria. Some of these products exhibit good activities to significant antibacterial activity.


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