scholarly journals Anthraquinones from the Roots of Kniphofia insignis and Evaluation of Their Antimicrobial Activities

2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Asnakew Amare Tadesse ◽  
Negera Abdissa Ayana ◽  
Dele Abdissa Keneni
Keyword(s):  
Antimicrobial Activities ◽  
Fungal Strain ◽  
Bacterial Strains ◽  
Zone Of Inhibition ◽  
Fusarium Spp ◽  
E Coli ◽  
Spectroscopic Analyses ◽  
Crude Extracts ◽  
Antimicrobial Assay

Sequential extraction using a cold maceration method and column chromatographic separation of the roots Kniphofia insignis headed to the isolation of three anthraquinones: one monomeric anthraquinone (1) and two dimeric anthraquinones (2 and 3). It was further purified by Sephadex LH-20 and recrystallized. The structures of these compounds were established based on the spectroscopic analyses including NMR (1H-NMR and 13C-NMR and infrared) and comparison with reported literatures. In an in vitro antimicrobial assay of the crude extracts, the isolated compounds were made against four bacterial strains (S. aureus ATCC 25923, B. subtilis ATCC 6633, E. coli ATCC 35218, and P. aeruginosa ATCC 27853) and Fusarium spp. fungal strain. In the crude extracts of chloroform, substantial antimicrobial activity was seen with the highest activity against B. subtilis (16 mm) and E. coli (22 mm). Meanwhile, compound 1 has a better zone of inhibition with 14 mm against P. aeruginosa, whereas compound 2 showed better activity (13 mm) against Fusarium spp. fungal strain.

scholarly journals Synthesis and antimicrobial activity of some new N-(aryl-oxo-alkyl)-5-arylidene-thiazolidine-2,4-diones

2014 ◽  
Vol 79 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Anca Stana ◽  
Brînduşa Tiperciuc ◽  
Mihaela Duma ◽  
Adrian Pîrnău ◽  
Philippe Verité ◽  
...  
Keyword(s):  
Antimicrobial Activities ◽  
Fungal Strain ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Reference Drug ◽  
Gram Negative ◽  
E Coli ◽  
Inhibitory Activities

A series of new 5-(2,6-dichlorobenzylidene)thiazolidine-2,4-dione and 5-(4-methoxy-benzylidene)thiazolidine-2,4-dione derivatives (3a-h and 5a-h) were synthesized starting from 5-arylidene-thiazolidine-2,4-dione and ?-halo-ketones. The structural elucidation of the newly synthesized compounds was based on elemental analysis and spectroscopic data (MS, 1H-NMR, 13C-NMR). The synthesized compounds were screened for their antimicrobial activities against several pathogenic strains of Gram-positive and Gram-negative bacteria and one fungal strain (Candida albicans), assessed in vitro as growth inhibition diameters. Some of them displayed better inhibitory activities than that of the reference drug against the Gram-positive S. aureus, B. cereus, L. monocytogenes bacterial strains, and showed good antifungal activity against C. albicans, while the antibacterial activity against Gram-negative E. coli and S. typhimurium bacterial strains was moderate.

scholarly journals Synthesis of sulfonamides bearing 1,3,5-triarylpyrazoline and 4-thiazolidinone moieties as novel antimicrobial agents

2020 ◽  
Vol 85 (2) ◽  
pp. 155-162
Author(s):  
Thi-Dan Thach ◽  
Thi Le ◽  
Thien-Annguyen Nguyen ◽  
Chi-Hien Dang ◽  
Van-Su Dang ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Antimicrobial Activities ◽  
Significant Inhibition ◽  
Mercaptoacetic Acid ◽  
Bacterial Strains ◽  
Reference Drug ◽  
E Coli ◽  
Yeast Strains ◽  
Microbial Strains

Two series of sulfonamides were synthesized from 4-hydrazinylbenzenesulfonamide as the key starting material. 1,3,5-Triarylpyrazoline sulfonamides (2a?i) were obtained by cyclocondensation of various chalcones in 53? ?64 % yields, while 4-thiazolidinone derivatives (4a?e) were synthesized by cyclocondensation between mercaptoacetic acid and different phenylhydrazones in 43?62 % yields. The synthesized compounds were characterized based on FTIR, 1H-NMR, 13C-NMR and HRMS data. The sulfonamides were evaluated for their in vitro antimicrobial activities against four bacterial strains (E. coli, P. aeruginosa, B. subtillis and S aureus), two filamentous fungal strains (A. niger and F. oxysporum) and two yeast strains (C. albicans and S. cerevisiae). Seven pyrazolines, 2a?c and 2e?h, exhibited significant inhibition of different microbial strains. Among them, compound 2b displayed good antifungal activity against A. niger (MIC value at 12.5 ?g mL-1) over the reference drug.

Two highly acetylated sterols from the marine sponge Dysidea sp.

2017 ◽  
Vol 72 (1) ◽  
pp. 49-52 ◽  
Author(s):  
Yu Lu ◽  
Ming Zhao
Keyword(s):  
High Resolution ◽  
Mass Spectroscopy ◽  
2D Nmr ◽  
Antimicrobial Activities ◽  
Marine Sponges ◽  
Bacterial Strains ◽  
Chemical Structures ◽  
Spectroscopic Analyses ◽  
Impact Mass

AbstractTwo new highly acetylated steroids, named dysiroid A (1) and dysiroid B (2), together with a known compound (3) were isolated from the marine sponges Dysidea sp. The chemical structures of 1 and 2 were elucidated by spectroscopic analyses including 1D and 2D NMR experiments and high-resolution electrospray impact mass spectroscopy. Their in vitro antimicrobial activities against a panel of bacterial strains were evaluated. Compounds 1 and 2 showed potent activity against some of the strains with minimum inhibitory concentrations ranging from 4 to 8 μg mL−1.

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

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.

Copper(II) mixed-ligand complexes containing 1, 10-phenanthroline, adenine and thymine: Synthesis, characterization and antibacterial activities

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Copper Complexes ◽  
Antimicrobial Agents ◽  
Conductivity Measurement ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
E Coli ◽  
In Vivo Cytotoxicity

New copper complexes, [Cu(phen)2(Thy)]2Cl and [Cu(phen)2(Ad)]2Cl (phen = 1,10-phenantroline, Ad (Adenine, a purine nucleobase) and Thy (Thymine, a pyrimidine nucleobase)), were synthesized and characterized by atomic absorption spectroscopy (AAS), conductivity measurement, UV-visible and infrared (IR) techniques. The complexes were tested for their antimicrobial activity against two gram positive and two gram negative bacterial strains. The results of in vitro antimicrobial activities were compared with the commercially available antimicrobial agents (ciprofloxacin and chloramphenicol). This comparative study has demonstrated that [Cu(phen)2(Thy)]2Cl inhibited the growth of methicillin resistant Staphylococcus aureous (MRSA), Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumonia) better than chloramphenicol by 11.25%, 19.41% and 25.35%, respectively. It also showed better activities than ciprofloxacine on MRSA and K. pneumoniae by 2.50% and 12.13%, respectively. Similarly, [Cu(phen)2(Ad)]2Cl demonstrated better inhibitions than chloramphenicol against MRSA, E. coli and K. pneumoniae by 11.24%, 2.48% and 9.06%, respectively. Therefore, after in vivo cytotoxicity investigations, these complexes could be considered as potential antimicrobial agents.

scholarly journals The Disulfide Bond of the Peptide Thanatin Is Dispensible for Its Antimicrobial ActivityIn VivoandIn Vitro

2016 ◽  
Vol 60 (7) ◽  
pp. 4283-4289 ◽  
Author(s):  
Bo Ma ◽  
Chao Niu ◽  
Ying Zhou ◽  
Xiaoyan Xue ◽  
Jingru Meng ◽  
...  
Keyword(s):  
Disulfide Bond ◽  
Umbilical Vein ◽  
Low Cost ◽  
Survival Rates ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
Content Type ◽  
E Coli

ABSTRACTThanatin (THA) displays potent antibiotic activity, especially against extended-spectrum-β-lactamase (ESBL)-producingEscherichia colibothin vitroandin vivo, with minimal hemolytic toxicity and satisfactory stability in plasma. However, the high cost of thanatin significantly limits its development and clinical application. To reduce the cost of peptide synthesis, a formulation of cyclic thanatin (C-thanatin) called linear thanatin (L-thanatin) was synthesized and its activity was evaluatedin vivoandin vitro. Results showed that C-thanatin and L-thanatin MICs did not differ against eight Gram-negative and two Gram-positive bacterial strains. Furthermore, the survival rates of ESBL-producing-E. coli-infected mice were consistent after C-thanatin or L-thanatin treatment at 5 or 10 mg/kg of body weight. Neither C-thanatin nor L-thanatin showed toxicity for human red blood cells (hRBCs) and human umbilical vein endothelial cells (HUVECs) at a concentration as high as 256 μg/ml. Results of circular dichroism spectroscopy indicated that the secondary structure of L-thanatin is extremely similar to that of C-thanatin. Membrane permeabilization and depolarization assays showed that C-thanatin and L-thanatin have similar abilities to permeabilize the outer and inner membranes and to induce membrane depolarization in ESBL-producingE. coli. However, neither of them caused significant HUVEC membrane permeability. These findings indicate that the two peptides have similar effects on bacterial cell membranes and that the disulfide bond in thanatin is not essential for its antimicrobial activitiesin vivoandin vitro. L-thanatin is thus a promising low-cost peptide candidate for treating ESBL-producingE. coliinfections.

scholarly journals Ofloxacin-Loaded Liposomes: In Vitro Activity and Drug Accumulation in Bacteria

2000 ◽  
Vol 44 (9) ◽  
pp. 2458-2464 ◽  
Author(s):  
Pio M. Furneri ◽  
Massimo Fresta ◽  
Giovanni Puglisi ◽  
Gianna Tempera
Keyword(s):  
Antimicrobial Activities ◽  
Culture Collection ◽  
Free Drug ◽  
Molar Ratio ◽  
In Vitro Activity ◽  
Wild Type ◽  
Bacterial Strains ◽  
E Coli ◽  
Liposome Formulation

ABSTRACT Different ofloxacin-loaded unilamellar vesicles were prepared by the extrusion technique, and their antimicrobial activities were determined in comparison to those of the free drug by means of MIC determinations with both American Type Culture Collection standards and wild-type bacterial strains (six strains of Enterococcus faecalis, seven strains of Escherichia coli, six strains of Staphylococcus aureus, and six strains ofPseudomonas aeruginosa). The accumulation of ofloxacin and liposome-ofloxacin was measured by determining the amount of the drug inside the bacteria as a function of time. Encapsulated fluoroquinolone yielded MICs which were at least twofold lower than those obtained with the free drug. In particular, liposomes made up of dimyristoylphosphatidylcholine-cholesterol-dipalmitoylphosphatidylserine and dimyristoylphosphatidylcholine-cholesterol-dihexadecylphosphate (4:3:4 molar ratio) provided the best improvement in antimicrobial activity against the various bacterial strains investigated. The liposome formulation produced higher intracellular fluoroquinolone concentrations than those achieved simultaneously with the free drug in both E. coli and P. aeruginosa.

scholarly journals Synthesis, Characterization, and Antibacterial Activities of Novel Sulfonamides Derived through Condensation of Amino Group Containing Drugs, Amino Acids, and Their Analogs

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Muhammad Abdul Qadir ◽  
Mahmood Ahmed ◽  
Muhammad Iqbal
Keyword(s):  
Amino Acids ◽  
Spectral Analysis ◽  
New Products ◽  
Antibacterial Activities ◽  
Amino Group ◽  
Bacterial Strains ◽  
Zone Of Inhibition ◽  
E Coli ◽  
Ft Ir

Novel sulfonamides were developed and structures of the new products were confirmed by elemental and spectral analysis (FT-IR, ESI-MS,1HNMR, and13CNMR). In vitro, developed compounds were screened for their antibacterial activities against medically important gram (+) and gram (−) bacterial strains, namely,S. aureus,B. subtilis,E. coli, andK. pneumoniae. The antibacterial activities have been determined by measuring MIC values (μg/mL) and zone of inhibitions (mm). Among the tested compounds, it was found that compounds 5a and 9a have most potent activity againstE. coliwith zone of inhibition:31±0.12 mm (MIC: 7.81 μg/mL) and30±0.12 mm (MIC: 7.81 μg/mL), respectively, nearly as active as ciprofloxacin (zone of inhibition:32±0.12 mm). In contrast, all the compounds were totally inactive against the gram (+)B. subtilis.

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF 3-FORMYL INDOLE BASED SCHIFF BASES

2018 ◽  
Vol 7 (6) ◽  
Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Analysis ◽  
Schiff Bases ◽  
Antimicrobial Agents ◽  
Biological Evaluation ◽  
Fungal Strain ◽  
Bacterial Strains ◽  
Standard Drug ◽  
Gram Negative ◽  
E Coli

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.

scholarly journals Antimicrobial Activity and Chemical Characterization of a Non-Polar Extract of Saffron Stamens in Food Matrix

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 703
Author(s):  
Severino Zara ◽  
Giacomo L. Petretto ◽  
Alberto Mannu ◽  
Giacomo Zara ◽  
Marilena Budroni ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Fatty Acid Content ◽  
Chemical Characterization ◽  
Antimicrobial Activities ◽  
Added Value ◽  
Gas Chromatography Mass Spectrometry ◽  
Food Matrix ◽  
Bacterial Strains ◽  
By Products

The production of saffron spice generates large quantities of plant by-products: over 90% of the plant material collected is discarded, and a consideration fraction of this waste is plant stamens. This work investigated the chemical composition and the antimicrobial activities of the non-polar fraction extracted from four different saffron flower stamens. The chemical composition of ethereal extracts of the saffron stamens was qualitatively assessed by means of gas–chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) analyses. These analyses revealed ethereal extracts to possess a high polyunsaturated fatty acid content. In vitro antibacterial activity of stamen extracts showed no large differences between Gram-positive and Gram-negative bacteria in terms of minimal inhibitory concentration (MIC). In food matrix microbial analysis of the bacterial strains belonging to the main foodborne pathogen species, including Staphylococcus aureus DSM 20231, Escherichia coli DSM 30083, and Listeria monocytogenes DSM 20600, using low-fat UHT milk, revealed a statistically significant reduction in the number of cells (particularly for E. coli and S. aureus with a complete elimination of the population of the two target bacteria following incubation in diethyl ether extracts of saffron stamen (DES) at high concentrations tested, both at 37 °C and 6 °C (for 48 h and 7 days, respectively). A synergic effect was observed when the pathogens were incubated at 6 °C with DES. This work shows these by-products to be excellent sources of bioactive compounds, which could be exploited in high-added-value products, such as food, cosmetics, and drugs.

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