EVALUATION OF POTENTIAL ANTIMICROBIAL ACTIVITY OF SYNTHETIC FLAVONOIDS

Introduction: In recent times, most of the currently available antimicrobial agents have developed resistance. Extensive pharmacological activities including bactericidal and bacteriostatic nature of flavonoids, made them as priority agents in this aspect of research study. Synthetic flavonoids such as hydroxy thiophen derivatives were considered to evaluate for antimicrobial activity in this study. Objective: The present study involves the analysis for antimicrobial activity of thiophen substituted synthetic flavonoids. Methods: Claisen-Schmidt method of condensation fallowed by oxidative cyclization reactions from substituted hydroxyacetophenone with aromatic aldehydes were used to synthesize the various analogues of flavonoid compounds. Then these compounds after their FTIR, 1H NMR, MS spectral characterization and elemental analysis, were screened for in vitro antibacterial and antifungal activity by using disc diffusion method followed by determining their respective zone of inhibitions. Results: All the synthesized test flavonoid compounds exhibited the good antibacterial and antifungal spectrum activity over B. subtilis, S. aureus, E. coli and P. aeurugenosa bacteria and Candida albicans and Aspergillus niger fungal microbes. However compounds such as F1, F2 and F4 showed moderately significant antibacterial activity against P. aerugenosa organism than the other test compounds and the same F1 and F2 test compounds exhibited significant antifungal activity at100µg concentration. Conclusion: The present study demonstrated that the novel thiophen substituted flavonoids (F1, F2, F3 and F4 ) found to have promising antimicrobial and antifungal activity which needs to be confirmed by in vivo studies.

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An In Vitro Study on the Antimicrobial Properties of Essential Oil Modified Resin Composite against Oral Pathogens

Materials ◽

10.3390/ma13194383 ◽

2020 ◽

Vol 13 (19) ◽

pp. 4383

Author(s):

Barbara Lapinska ◽

Aleksandra Szram ◽

Beata Zarzycka ◽

Janina Grzegorczyk ◽

Louis Hardan ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antibacterial Activity ◽

Antifungal Activity ◽

Antimicrobial Agents ◽

Resin Composite ◽

Antimicrobial Properties ◽

In Vitro Study ◽

Diffusion Method ◽

Oral Pathogens

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.

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Antimicrobial Activity from Species Plectranthus amboinicus (Lour.) Spreng, a Review

European Journal of Medicinal Plants ◽

10.9734/ejmp/2020/v31i1830337 ◽

2020 ◽

pp. 1-14

Author(s):

Juliane Maria dos Santos Silva ◽

Jackson Roberto Guedes da Silva Almeida ◽

Cristiane dos Santos Cerqueira Alves ◽

Daniel Amando Nery ◽

Livia Maria Oliveira Damasceno ◽

...

Keyword(s):

Antimicrobial Activity ◽

Pathogenic Bacteria ◽

Antimicrobial Agents ◽

Therapeutic Potential ◽

In Vivo Studies ◽

Synergistic Activity ◽

Popular Medicine ◽

Plectranthus Amboinicus

Introduction: Nowadays, several bacteria have acquired resistance to available antimicrobial agents making necessary the search for new therapeutic alternatives. Plectranthus amboinicus L. is a succulent and aromatic herb, popularly known as thick leaf mint, used in popular medicine for the treatment of colds, digestive diseases, asthma, headache and to fight pathogenic bacteria activity. In view the antimicrobial activity of P. amboinicus this study had as aim to review publications involving researches about antimicrobial activity of this species. Materials and Methods: For this, PubMed, Scopus, Science Direct and Scielo databases were consulted in November 2020 using the keywords Plectranthus amboinicus and antimicrobial activity. In vitro and/or in vivo studies on the antimicrobial activity of the species in the last 10 years were considered. Results: The main microorganisms evaluated were: Klebsiella pneumoniae, Mycobacterium tuberculosis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and some Candida species. The essential oils had carvacrol, germacrene D, thymol and camphor as main constituents. Most studies evaluated the antimicrobial activity using broth dilution and agar diffusion methods. In most studies essential oil, extracts and/or isolated substances showed significant antimicrobial activity. Synergistic activity was also observed through association with antibiotics. Conclusion: P. amboinicus has therapeutic potential for antimicrobial treatments and can be an alternative to the treatment of resistant microorganisms and that further in vivo and clinical studies with the species are still needed.

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Evaluation of In vitro Antimicrobial and In vivo Cytotoxic Properties of Peroxo Coordination Complexes of Mg(II), Mn(II), Fe(II) & Ni(II)

Dhaka University Journal of Pharmaceutical Sciences ◽

10.3329/dujps.v3i1.184 ◽

1970 ◽

Vol 3 (1) ◽

Author(s):

Kudrat E Zahan ◽

MD. Shamin Hossain ◽

Shuranjan Sarkar ◽

Md. Mukhlesur Rahman ◽

Md. Akhter Farooque ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antifungal Activity ◽

Cytotoxic Activity ◽

Full Text ◽

Brine Shrimp ◽

Coordination Complexes ◽

Antibacterial And Antifungal Activities ◽

Antibacterial And Antifungal

Six newly synthesized nickel peroxo coordination complexes, [Mg2(2-ap)2(O2)(OH), A], [Mn(2-ap) (ED)(O2), B], [Fe(2-ab)(ED)(O2), C], [Fe(2-ap)(ED)(O2), D], [Ni2(2-ab)2(O2)(OH), E] and [Ni2(2-ap)2(O2)(OH), F] showed significant antibacterial and antifungal activities. The minimum inhibitory concentrations (MIC) of these compounds were found in the range of 8-128 µg/ml. Among these compounds, F showed maximum cytotoxicity (LC50 = 3.62 µg/ml) in brine shrimp lethality bioassay. Key words: Peroxo coordination complexes; Antimicrobial activity; antifungal activity; cytotoxic activity. Dhaka Univ. J. Pharm. Sci. Vol.3(1-2) 2004 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website

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An experimental in-vitro study to evaluate the anti-helicobacter activity of Glycyrrhetinic acid

Revista Romana de Medicina de Laborator ◽

10.2478/rrlm-2019-0003 ◽

2019 ◽

Vol 27 (1) ◽

pp. 63-71 ◽

Cited By ~ 1

Author(s):

Muhammet Murat Celik ◽

Nizami Duran

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Agents ◽

In Vitro Study ◽

Glycyrrhetinic Acid ◽

Test Method ◽

In Vivo Studies ◽

H Pylori ◽

Mic Value

Abstract Aim: The aim of this study was to investigate the in-vitro efficacy of Glycyrrhetinic acid against Helicobacter pylori (H. pylori) strains, as compared with conventional antibacterial agents. Methods: A total of 41 H. pylori isolates were used, 6 of which were of standard strains (NCTC 1637), 8 of which were drug-sensitive, and 27 were resistant to drugs isolates. Clarithromycin and metronidazole resistance in all strains of H. pylori were determined by the Epsilometer test (E-test) method. MIC study was performed by using microdilution broth method. Results: Glycyrrhetinic acid was found to be effective against H. pylori NCTC 1637 in doses of 12.0±4.38 µg/mL, while the MIC value of clinical H. pylori isolates susceptible to antimicrobials was 20.8±10.11 µg/ml. It was found that the MIC values for antimicrobial-sensitive clinical H. pylori isolates was higher when compared with H. pylori NCTC 1637 strains. The MIC values of the standard antimicrobial agents against drug-resistant H. pylori strains were higher than H. pylori NCTC 1637 strains and drug-sensitive H. pylori strains. The MIC value was found to be 14.22±7.77 µg/ml for metronidazole, 3.89±1.90 µg/ml for clarithromycin, 2.33±1.0 µg/ml for amoxicillin, 2.44±0.88 µg/ml for levofloxacin and 4.89±2.47 µg/ml for tetracycline, whereas the MIC value of Glycyrrhetinic acid was 26.67±8.0 µg/ml in metronidazole-resistant H. pylori isolates. Besides, MIC values of the antimicrobials and 18ß-Glycyrrhetinic acid among the strains resistant to clarithromycin were as follows: 3.25±2.12 µg/ml for metronidazole, 9.71±4.54 µg/ml for clarithromycin, 2.06±1.32 µg/ml for amoxicillin, 3.88±4.22 µg/ml for levofloaxacin and 3.25±1.04 µg/mL for tetracycline and 22.0±11.11 µg/ml for Glycyrrhetinic acid. Conclusion: Glycyrrhetinic acid had significant antimicrobial activity against H. pylori strains. Although further in-vivo studies are needed on antimicrobial activity of Glycyrrhetinic acid, increased resistance to drugs currently used in treatment suggests that Glycyrrhetinic acid may be a potential agent for the treatment of H. pylori.

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Antibacterial Activity of Mouthwash Incorporated with Silica Nanoparticles against S. aureus, S. mutans, E. faecalis: An in-vitro Study

Journal of Pharmaceutical Research International ◽

10.9734/jpri/2020/v32i1630646 ◽

2020 ◽

pp. 25-33

Author(s):

Manali Deb Barma ◽

Srisakthi Dorai Kannan ◽

Meignana Arumugham Indiran ◽

S. Rajeshkumar ◽

R. Pradeep Kumar

Keyword(s):

Antimicrobial Activity ◽

Silica Nanoparticles ◽

Antimicrobial Agents ◽

In Vitro Study ◽

Silica Nanoparticle ◽

Xrd Analysis ◽

Diffusion Method ◽

Oral Pathogens

Silica based nanoparticles are used in various fields of medical sciences to diagnose, control disease, for genetic disorders, owing to their size, surface area, biocompatibility and low toxicity. In dentistry, silica nanoparticles have been used as dental filler, teeth whitening agent but limited evidence is there regarding antimicrobial activity against oral pathogens. Therefore, the current study was conducted to assess the anti-bacterial activity of mouthwash incorporated with silica nanoparticles against oral pathogens. Tetraethoxysilane, ammonium hydroxide, absolute ethanol were used and centrifuged to obtain the silica nanoparticle pellet. XRD analysis was done to confirm the characterization of the thus obtained silica nanoparticle. The mouthwash was prepared with the synthesized silica nanoparticle as the main constituent. Agar well diffusion method was used to assess the antimicrobial activity against S. mutans, S. aureus and E. faecalis. The XRD analysis confirmed the amorphous nature of the synthesized silica nanoparticles. The zone of inhibition was found to increase as the concentrations increased mainly for S. aureus and E. faecalis. The synthesized nanoparticles incorporated mouthwash showed good potential as antimicrobial agents against strains of gram positive bacteria. Further animal studies/in vivo research should be conducted to validate the above findings.

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Recent Advances in Iron Chelation and Gallium-Based Therapies for Antibiotic Resistant Bacterial Infections

International Journal of Molecular Sciences ◽

10.3390/ijms22062876 ◽

2021 ◽

Vol 22 (6) ◽

pp. 2876

Author(s):

Víctor Vinuesa ◽

Michael J. McConnell

Keyword(s):

Antimicrobial Activity ◽

Bacterial Infections ◽

Antimicrobial Agents ◽

Bacterial Species ◽

Iron Chelation ◽

Iron Chelator ◽

In Vivo Studies ◽

Iron Chelators

Iron is essential for multiple bacterial processes and is thus required for host colonization and infection. The antimicrobial activity of multiple iron chelators and gallium-based therapies against different bacterial species has been characterized in preclinical studies. In this review, we provide a synthesis of studies characterizing the antimicrobial activity of the major classes of iron chelators (hydroxamates, aminocarboxylates and hydroxypyridinones) and gallium compounds. Special emphasis is placed on recent in-vitro and in-vivo studies with the novel iron chelator DIBI. Limitations associated with iron chelation and gallium-based therapies are presented, with emphasis on limitations of preclinical models, lack of understanding regarding mechanisms of action, and potential host toxicity. Collectively, these studies demonstrate potential for iron chelators and gallium to be used as antimicrobial agents, particularly in combination with existing antibiotics. Additional studies are needed in order to characterize the activity of these compounds under physiologic conditions and address potential limitations associated with their clinical use as antimicrobial agents.

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Copper-catalyzed Convenient Synthesis and SAR Studies of Substituted-1,2,3-triazole as Antimicrobial Agents

Letters in Drug Design & Discovery ◽

10.2174/1570180815666180326153322 ◽

2018 ◽

Vol 16 (1) ◽

pp. 3-10

Author(s):

Aniket P. Sarkate ◽

Kshipra S. Karnik ◽

Pravin S. Wakte ◽

Ajinkya P. Sarkate ◽

Ashwini V. Izankar ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antifungal Activity ◽

Antimicrobial Agents ◽

Cycloaddition Reaction ◽

Dipolar Cycloaddition ◽

One Pot ◽

Triazole Derivatives ◽

Sar Studies ◽

Convenient Synthesis ◽

Antibacterial And Antifungal

Background:A novel copper-catalyzed synthesis of substituted-1,2,3-triazole derivatives has been developed and performed by Huisgen 1,3-dipolar cycloaddition reaction of azides with alkynes. The reaction is one-pot multicomponent.Objective:We state the advancement and execution of a methodology allowing for the synthesis of some new substituted 1,2,3-triazole analogues with antimicrobial activity.Methods:A series of triazole derivatives was synthesized by Huisgen 1,3-dipolar cycloaddition reaction of azides with alkynes. The structures of the synthesized compounds were elucidated and confirmed by 1H NMR, IR, MS and elemental analysis. All the synthesized compounds were tested for their antimicrobial activity against a series of strains of Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and against the strains of Candida albicans, Aspergillus flavus and Aspergillus nigar for antifungal activity, respectively.Results and Conclusion:From the antimicrobial data, it was observed that all the newly synthesized compounds showed good to moderate level of antibacterial and antifungal activity.

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Synthesis of Novel 3(N,N-dialkylamino)alkyl/phenyl Substituted Thieno [2,3-d]pyrimidinones as H1-Anti-Histaminic and Antimicrobial Agents

Current Bioactive Compounds ◽

10.2174/1573407214666180226130957 ◽

2019 ◽

Vol 15 (1) ◽

pp. 63-70

Author(s):

Shiv Dev Singh ◽

Arvind Kumar ◽

Firoz Babar ◽

Neetu Sachan ◽

Arun Kumar Sharma

Keyword(s):

Antimicrobial Activity ◽

Potassium Hydroxide ◽

Antimicrobial Agents ◽

Pyrimidine Ring ◽

Antimicrobial Activities ◽

Screening Methods ◽

Chlorpheniramine Maleate ◽

In Vivo Screening

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.

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SYNTHESIS AND STRUCTURAL ELUCIDATION OF AMINO ACETYLENIC AND THIOCARBAMATES DERIVATIVES FOR 2-MERCAPTOBENZOTHIAZOLE AS ANTIMICROBIAL AGENTS

International Journal of Pharmacy and Pharmaceutical Sciences ◽

10.22159/ijpps.2017v9i2.15760 ◽

2017 ◽

Vol 9 (2) ◽

pp. 192

Author(s):

Aseel Alsarahni ◽

Zuhair Muhi Eldeen ◽

Elham Al-kaissi ◽

Ibrahim Al- Adham ◽

Najah Al-muhtaseb

Keyword(s):

Antimicrobial Activity ◽

Elemental Analysis ◽

Antimicrobial Agents ◽

Diffusion Method ◽

Benzothiazole Derivatives ◽

H Nmr ◽

Ft Ir ◽

Potential Antimicrobial Activity ◽

C Nmr

Objective: To design and synthesize amino acetylenic and thiocarbonate of 2-mercapto-1,3-benthiazoles as potential antimicrobial agents.Methods: A new series of 2-{[4-(t-amino-1-yl) but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole derivatives (AZ1-AZ6), and S-1,3-benzothiazol-2-yl-O-alkyl carbonothioate derivatives were synthesised, with the aim that the target compounds show new and potential antimicrobial activity. The elemental analysis was indicated by the EuroEA elemental analyzer, and biological characterization was via IR, 1H-NMR, [13]C-NMR, DSC were determined with the aid of Bruker FT-IR and Varian 300 MHz spectrometer using DMSO-d6 as a solvent. In vitro antimicrobial activity, evaluation was done for the synthesised compounds, by agar diffusion method and broth dilution test. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined. Results: The IR, 1H-NMR, 13C-NMR, DSC and elemental analysis were consistent with the assigned structures. Compound of 2-{[4-(4-methylpiperazin-1-yl)but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole (AZ1), 2-{[4-(2-methylpiperidin-1-yl)but-2-yn-1-yl]sulfanyl}-1,3-benzothiazole (AZ2), 2-{[4-(piperidin-1-yl) but-2-yn-1-yl]sulfanyl}-1, 3-benzothiazole (AZ6), S-1,3-benzothiazol-2-yl-O-ethyl carbonothioate (AZ7), and S-1,3-benzothiazol-2-yl-O-(2-methylpropyl) carbonothioate (AZ9) showed the highest antimicrobial activity against Pseudomonas aeruginosa (P. aeruginosa), AZ-9 demonstrated the highest antifungal activity against Candida albicans (C. albicans), with MIC of 31.25 µg/ml.Conclusion: These promising results promoted our interest to investigate other structural analogues for their antimicrobial activity further.

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Equilibrium distribution of radioxenon in tissue: xenon-hemoglobin association curve

Journal of Applied Physiology ◽

10.1152/jappl.1961.16.6.1065 ◽

1961 ◽

Vol 16 (6) ◽

pp. 1065-1070 ◽

Cited By ~ 207

Author(s):

Hadley L. Conn

Keyword(s):

Partition Coefficients ◽

Equilibrium Distribution ◽

Hemoglobin Concentration ◽

Gas Diffusion ◽

In Vivo Studies ◽

Diffusion Method ◽

Body Tissues ◽

Gas Diffusion Method

In vitro and in vivo studies were made of the equilibrium distribution of radioxenon in various organs and tissues of the dog and the xenon uptake compared with a water standard. Tissue-blood partition coefficients were calculated. The radioxenon-hemoglobin association curve was determined for dog and human hemoglobin and methemoglobin. The uptake of radioxenon by blood, due in particular to xenon-hemoglobin affinity, was appreciably greater than uptake either by water or by most other body tissues. Fat and brain were notable exceptions. Consequently, tissue-blood partition coefficients were about eight for fat, one for brain, and significantly less than one for other tissues studied. Acceptable accuracy for blood flow determinations with a radioxenon inert gas diffusion method would seem to depend on the use of a partition coefficient correction in turn corrected at least for the existing hemoglobin concentration. The uptake of xenon by hemoglobin had the characteristics of a solubility or a quasi-solubility phenomenon. The problem of the nature of the interaction is apparently not resolved. Submitted on June 19, 1961

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