Novel 3-Acetyl-2,5-disubstituted-1,3,4-oxadiazolines: Synthesis and Biological Activity

The aim of our study was the two-stage synthesis of 1,3,4-oxadiazole derivatives. The first step was the synthesis of hydrazide–hydrazones from 3-methyl-4-nitrobenzhydrazide and the corresponding substituted aromatic aldehydes. Then, the synthesized hydrazide–hydrazones were cyclized with acetic anhydride to obtain new 3-acetyl-2,3-disubstituted-1,3,4-oxadiazolines. All of obtained compounds were tested in in vitro assays to establish their potential antimicrobial activity and cytotoxicity. Our results indicated that few of the newly synthesized compounds had some antimicrobial activity, mainly compounds 20 and 37 towards all used reference bacterial strains (except Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa) and fungi. These substances showed a strong or powerful bactericidal effect, especially against Staphylococcus spp. belonging to Gram-positive bacteria. Compound 37 was active against Staphylococcus epidermidis at minimal inhibitory concentration (MIC) = 0.48 µg/mL and was characterized by low cytotoxicity. This compound possessed quinolin-4-yl substituent in the second position of 1,3,4-oxadiazole ring and 3-methyl-4-nitrophenyl in position 5. High effectiveness and safety of these derivatives make them promising candidates as antimicrobial agents. Whereas the compound 20 with the 5-iodofurane substituent in position 2 of the 1,3,4-oxadiazole ring showed the greatest activity against S. epidermidis at MIC = 1.95 µg/mL.

Download Full-text

In Vitro Bactericidal Activity of Human β-Defensin 3 against Multidrug-Resistant Nosocomial Strains

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.50.2.806-809.2006 ◽

2006 ◽

Vol 50 (2) ◽

pp. 806-809 ◽

Cited By ~ 80

Author(s):

Giuseppantonio Maisetta ◽

Giovanna Batoni ◽

Semih Esin ◽

Walter Florio ◽

Daria Bottai ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Pseudomonas Aeruginosa ◽

Antimicrobial Activity ◽

Bactericidal Activity ◽

Stenotrophomonas Maltophilia ◽

Bactericidal Effect ◽

Multidrug Resistant ◽

Bacterial Strains ◽

Gram Negative

ABSTRACT The antimicrobial activity of human β-defensin 3 (hBD-3) against multidrug-resistant clinical isolates of Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Acinetobacter baumannii was evaluated. A fast bactericidal effect (within 20 min) against all bacterial strains tested was observed. The presence of 20% human serum abolished the bactericidal activity of hBD-3 against gram-negative strains and reduced the activity of the peptide against gram-positive strains.

Download Full-text

Novel 2,4,6-Trimethylbenzenesulfonyl Hydrazones with Antibacterial Activity: Synthesis and In Vitro Study

Materials ◽

10.3390/ma14112723 ◽

2021 ◽

Vol 14 (11) ◽

pp. 2723

Author(s):

Łukasz Popiołek ◽

Sylwia Szeremeta ◽

Anna Biernasiuk ◽

Monika Wujec

Keyword(s):

Antimicrobial Activity ◽

Antibacterial Activity ◽

Potential Application ◽

Antimicrobial Agents ◽

Inhibitory Concentration ◽

Condensation Reaction ◽

In Vitro Study ◽

In Vitro Bioactivity ◽

Bacterial Strains

This research describes the synthesis and in vitro antimicrobial activity study of a series of 2,4,6-trimethylbenzenesulfonyl hydrazones. Twenty-five hydrazones (2–26) were synthesized on the basis of condensation reaction. The in vitro bioactivity study confirmed the potential application of obtained derivatives as antimicrobial agents. Among the tested compounds, the highest activity was discovered for derivative 24, which possessed minimal inhibitory concentration (MIC) ranging from 7.81 to 15.62 µg/mL against Gram-positive reference bacterial strains. Synthesized benzenesulfonyl hydrazones can be applied as potential ligands for the synthesis of bioactive metal complexes.

Download Full-text

In vitro Assessment of Bacterial Strains Associated with Microalgae as Potential Probiotics

Pertanika Journal of Tropical Agricultural Science ◽

10.47836/pjtas.44.1.12 ◽

2021 ◽

Vol 44 (1) ◽

Author(s):

Aimi Zabidi ◽

Natasya-Ain Rosland ◽

Jasmin Yaminudin ◽

Murni Karim

Keyword(s):

Antimicrobial Activity ◽

In Vitro Assays ◽

Disc Diffusion ◽

Bacterial Strains ◽

Pathogenic Vibrio ◽

Fish And Shellfish ◽

Diffusion Assay ◽

Vibrio Spp

Bacteria and microalgae are essential elements in the aquatic ecosystem, co-existing and having constant interactions with each other which help microalgae to exert its beneficial effect as probiotics in aquaculture. This research aims to isolate and identify potential probiotics from different species of microalgae and to evaluate their antimicrobial activity against pathogenic Vibrio spp. via series of in vitro assays; disc diffusion, well diffusion, and co-culture assays. A total of 18 bacterial strains were isolated from five species of microalgae; Chlorella sp., Nannochloropsis sp., Amphora sp., Chaetoceros sp., and Spirulina sp.. The isolated strains were tested in in vitro antagonistic assay against four Vibrio spp. (Vibrio harveyi, Vibrio alginolyticus, Vibrio vulnificus, and Vibrio parahaemolyticus). Seventeen strains demonstrated antimicrobial activity with the highest inhibition was observed by strain SPS11 against V. parahaemolyticus (12.6 ± 0.36 mm) in disc diffusion assay and strain NAS32 showed 13.2 ± 0.45 mm clear zone against V. vulnificus in well diffusion assay. In co-culture assay, both the SPS11 and NAS32 were able to reduce the growth of V. parahaemolyticus and V. harveyi at concentration of 106 and 108 CFU mL-1, respectively. Strains SPS11 and NAS32 were characterized as gram positive bacteria with rod shape and further identified as Lysinibacillus fusiformis (SPS11) and Lysinibacillus sphaericus (NAS32) using 16s rRNA. These two strains should be further studied in in vivo challenged experiments in fish and shellfish to explore their probiotic effects.

Download Full-text

Design, Synthesis, and Evaluation of Novel 3-, 4-substituted, and 3,4-di Substituted Quinazoline Derivatives as Antimicrobial Agents

Revista de Chimie ◽

10.37358/rc.20.2.7951 ◽

2020 ◽

Vol 71 (2) ◽

pp. 422-435

Author(s):

Farag A. El-Essawy ◽

Abdulrahman I. Alharthi ◽

Mshari A. Alotaibi ◽

Nancy E. Wahba ◽

Nader M. Boshta

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Agents ◽

Antimicrobial Activities ◽

Bacterial Strains ◽

Gram Positive ◽

Design Synthesis ◽

Gram Negative ◽

Spectroscopic Analyses ◽

Quinazoline Derivatives

A novel series of 3-, 4-substituted, and 3,4-di substituted quinazoline derivatives were prepared via various cyclized regents and most of the newly prepared compounds evaluated for their antimicrobial activities in vitro against Gram-positive, Gram-negative bacterial strains and fungi strains. The structures of the quinazoline derivatives have been confirmed using spectroscopic analyses (IR, NMR, and EI-MS). Some of the synthesized derivatives displayed a moderate antimicrobial activity in comparison with reference drugs, for example compounds 13d, 15a, 17b, 18b, 18d, 25, and 29a-c. Among the synthesized compounds, the pyrimidoqunazoline derivative 6c elicited the highest activity.

Download Full-text

Synthesis and Evaluation of Some Novel Chromone Based Dithiazoles as Antimicrobial Agents

International Journal of Medicinal Chemistry ◽

10.1155/2013/815453 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Naureen Aggarwal ◽

Vishal Sharma ◽

Harpreet Kaur ◽

Mohan Paul Singh Ishar

Keyword(s):

Antimicrobial Activity ◽

Elemental Analysis ◽

Antimicrobial Agents ◽

Fungal Strain ◽

Bacterial Strains ◽

Standard Drug ◽

Fungal Strains ◽

Inhibitory Potential ◽

C Nmr

Novel substituted 1,2,4-dithiazolylchromones 3a–j were synthesized by the reaction of 3-formylchromones (1a–j) with two equivalents of p-chlorothiobenzamide (2) in dry xylene and characterized spectroscopically (IR, 1H and 13C NMR, mass) and elemental analysis. All synthesized compounds were screened for in vitro antimicrobial activity against various pathogenic bacterial and fungal strains and were found to possess good to moderate inhibitory potential against all tested strains. Antimicrobial results reveal that compounds bearing lipophilic electron withdrawing groups such as chloro and bromo displayed significant inhibitory potential against both bacterial and fungal strains. Particularly, compound 3c displayed significant inhibitory against bacterial strains and compound 3h exhibits significant inhibitory potential in comparison to standard drug fluconazole against fungal strain S. cerevisiae.

Download Full-text

Antimicrobial Activity of Essential Oils against Staphylococcus and Malassezia Strains Isolated from Canine Dermatitis

Microorganisms ◽

10.3390/microorganisms8020252 ◽

2020 ◽

Vol 8 (2) ◽

pp. 252 ◽

Cited By ~ 3

Author(s):

Valentina Virginia Ebani ◽

Fabrizio Bertelloni ◽

Basma Najar ◽

Simona Nardoni ◽

Luisa Pistelli ◽

...

Keyword(s):

Antimicrobial Activity ◽

Essential Oils ◽

Antifungal Drugs ◽

Thymus Vulgaris ◽

Bacterial Strains ◽

In Vivo Evaluation ◽

Malassezia Pachydermatis ◽

Antistaphylococcal Activity ◽

Staphylococcus Spp

Staphylococcus spp. bacteria are the most frequently involved agents in canine cutaneous infections. Treatment of these infections is based on antibiotic therapy, that often is not effective because of the antibiotic-resistance of the bacterial strains. Cutaneous staphylococcal infections are often complicated by Malassezia yeasts, that may be resistant to the conventional antifungal drugs. The present investigation was aimed to evaluate the in vitro antimicrobial activity of some essential oils (EOs) in view of a potential cutaneous application. In detail, EOs obtained from lemon verbena (Aloysia triphylla L’Hèr. Britton), cinnamon (Cinnamomum zeylanicum J. Presl), myrrh (Commiphora myrrha (Nees) Engl. var. molmol), lemongrass (Cymbopogon citratus (DC.) Stapf), litsea (Litsea cubeba (Lour.) Pers.), lemon balm (Melissa officinalis L.), oregano (Origanum vulgare L.), savory (Satureja montana L.), and thyme (Thymus vulgaris L.) were assayed against Staphylococcus spp. and Malassezia pachydermatis strains previously isolated from dogs with dermatitis. All EOs were tested by agar disk diffusion and minimum inhibitory concentration methods to verify the antistaphylococcal activity, and by a microdilution method to evaluate the activity against M. pachydermatis. O. vulgare, T. vulgaris, and S. montana showed the best antibacterial activity against all the selected strains, with MICs ranging from 0.29 to 0.58 mg/mL, from 0.58 to 1.16 mg/mL, and from 0.56 to 1.12 mg/mL, respectively, whereas A. triphylla (1.03 mg/mL) and S. montana (1.8 mg/mL) were the most active against M. pachydermatis. After a proper in vivo evaluation, O. vulgare, T. vulgaris, and S. montana EOs could be a promising treatment to combat canine cutaneous mixed infections.

Download Full-text

Synthesis, characterization, synergistic antimicrobial properties and molecular docking of sugar modified uridine derivatives

Ovidius University Annals of Chemistry ◽

10.2478/auoc-2021-0002 ◽

2021 ◽

Vol 32 (1) ◽

pp. 6-21

Author(s):

Jannatul Maowa ◽

Asraful Alam ◽

Kazi M. Rana ◽

Sujan Dey ◽

Anowar Hosen ◽

...

Keyword(s):

Antimicrobial Activity ◽

Molecular Docking ◽

Density Functional ◽

Antimicrobial Agents ◽

Antimicrobial Properties ◽

Docking Study ◽

Bacterial Strains ◽

Molecular Docking Study ◽

Antibacterial And Antifungal Activities

Abstract Nucleosides and their analogues are an important, well-established class of clinically useful medicinal agents that exhibit antiviral and anticancer activity. Thus, our research group has focused on the synthesis of new nucleoside derivatives that could be tested for their broad-spectrum biological activity. In this study, two new series of nucleoside derivatives were synthesized from uridine (1) through facile two-step reactions using the direct acylation method, affording 5’-O-acyl uridine derivatives in good yields. The isolated uridine analogs were further transformed into two series of 2’,3’-di-O-acyl derivatives bearing a wide variety of functionalities in a single molecular framework to evaluate their antimicrobial activity. The new synthesized compounds were characterized through physicochemical, elemental and spectroscopic analysis, and all were screened for their in vitro antimicrobial activity against selected human and plant pathogenic strains. The test compounds revealed moderate to good antibacterial and antifungal activities and were more effective against fungal phytopathogens than against bacterial strains, while many of them exhibited better antimicrobial activity than standard antibiotics. Minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) tests against all microorganisms were also conducted for five compounds based on their activity (6, 11, 13, 16, and 17). In addition, all the derivatives were optimized using density functional theory (DFT) B3LYP/6-31g+(d,p) calculations to elucidate their thermal and molecular orbital properties. A molecular docking study was performed using the human protein 5WS1 to predict their binding affinity and modes, and ADMET and SwissADME calculations confirmed the improved pharmacokinetic properties of the compounds. Besides, structure–activity relationship (SAR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) studies were also performed. Thus, the improvement of the bioactivity of these compounds is expected to significantly contribute to the design of more antimicrobial agents for therapeutic use in the future.

Download Full-text

Antimicrobial Activity of Highly Fluorinated Thiocarbamates and Dithiocarbamates

Current Chemical Biology ◽

10.2174/2212796812666180907153901 ◽

2019 ◽

Vol 13 (2) ◽

pp. 120-128

Author(s):

Amal Thebti ◽

Ines Chniti ◽

Med Abderrahmane Sanhoury ◽

Ikram Chehidi ◽

Hadda Imene Ouzari ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Activity ◽

Antibacterial Activity ◽

Antimicrobial Agents ◽

Fungal Species ◽

Penicillium Expansum ◽

Bacterial Strains ◽

Widespread Occurrence ◽

Antibacterial And Antifungal

Background:The widespread occurrence of resistance to current antibiotics has triggered increasing research efforts to design and develop innovative antibacterial and antifungal agents that could overcome such antimicrobial resistance.Objective:The aim of this work was the in vitro evaluation of twelve highly fluorinated Nmonosubstituted thiocarbamates and dithiocarbamates and six non-fluorinated analogs against nine bacterial strains and three fungal species.Methods:The in vitro antimicrobial activity against the tested microrganisms was evaluated using the microdilution broth method.Results:Escherichia coli ATCC 8739, Salmonella sp., Staphylococcus aureus 6539 and all the three fungi (Aspergillus niger, Aspergillus flavus and Penicillium expansum) exhibited the highest rate of susceptibility, whilst Enterococcus faecuim ATCC 19436 and particularly Escherichia coli DH5α were less susceptible. Thiocarbamate (1i) and dithiocarbamate (2i) showed both the lowest MIC values (3.9 µg/mL) and the widest spectrum of antibacterial activity. Furthermore, the N-ethyl derivatives inhibited more efficiently the growth of bacteria than N-aryl analogs.Conclusion:The fluorinated compounds showed, in general, a relatively more potent antibacterial activity than non-fluorinated counterparts. The results indicate that these thiocarbamates and dithiocarbamates could be promising candidates as potential antimicrobial agents.

Download Full-text

Red Algae as Source of Nutrients with Antioxidant and Antimicrobial Potential

Proceedings ◽

10.3390/foods_2020-07646 ◽

2020 ◽

Vol 70 (1) ◽

pp. 5

Author(s):

María. Carpena ◽

Cristina Caleja ◽

Paula García-Oliveira ◽

Carla Pereira ◽

Marina Sokovic ◽

...

Keyword(s):

Antimicrobial Activity ◽

Organic Acids ◽

Red Algae ◽

Antimicrobial Agents ◽

Biological Properties ◽

Nutritional Composition ◽

In Vitro Assays ◽

Antimicrobial Potential ◽

Antioxidant And Antimicrobial Activity

Seaweeds have been consumed since ancient times in different cultures, especially in Asian regions. Currently, several scientific studies have highlighted the nutritional value of algae as well as their biological properties. The present work was directed towards the determination of the nutritional composition (ash, protein, fat, carbohydrate content and energy value), the organic acids content, and also the antioxidant and antimicrobial activity of three typical red algae from Galicia: Chondrus crispus, Mastocarpus stellatus and Gigartina pistillata. The nutritional profile was determined by the methods described by AOAC, while organic acids were determined by UPFLC-PDA. The antioxidant activity was assessed using two in vitro assays: TBARS and OxHLIA. At last, antimicrobial activity was tested against two Gram (−), three Gram (+) and three fungus species. The results showed a similar nutritional composition among the three algae, with a low-fat content and a high content of proteins, carbohydrates and energy. Finally, in vitro assays showed significant antioxidant capacity of the three algae and antimicrobial potential against all the tested microorganisms. Thus, the study shows the potential of red algae to be part of the human diet, due to their nutritional content and bioactive properties, acting as antioxidant and antimicrobial agents.

Download Full-text

Synthesis, lipophilicity and antimicrobial activity evaluation of some new thiazolyl-oxadiazolines

Medicine and Pharmacy Reports ◽

10.15386/cjmed-473 ◽

2015 ◽

Vol 88 (4) ◽

pp. 521-529 ◽

Cited By ~ 1

Author(s):

Cristina Ioana Stoica ◽

Ioana Ionuț ◽

Adrian Pîrnău ◽

Carmen Pop ◽

Ancuța Rotar ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Agents ◽

Chemical Characterization ◽

Principal Component ◽

Antimicrobial Activities ◽

Bacterial Strains ◽

Pca Method ◽

Physical And Chemical ◽

Layer Chromatography

Background and aims. Synthesis of new potential antimicrobial agents and evaluation of their lipophilicity.Methods. Ten new thiazolyl-oxadiazoline derivatives were synthesized and their structures were validated by 1H-NMR and mass spectrometry. The lipophilicity of the compounds was evaluated using the principal component analysis (PCA) method. The necessary data for applying this method were obtained by reverse-phase thin-layer chromatography (RP-TLC). The antimicrobial activities were tested in vitro against four bacterial strains and one fungal strain.Results. The lipophilicity varied with the structure but could not be correlated with the antimicrobial activity, since this was modest.Conclusions. We have synthesized ten new heterocyclic compounds. After their physical and chemical characterization, we determined their lipophilicity and screened their antimicrobial activity.

Download Full-text