scholarly journals Structural Features of 1,3,4-Thiadiazole-Derived Ligands and Their Zn(II) and Cu(II) Complexes Which Demonstrate Synergistic Antibacterial Effects with Kanamycin

2020 ◽  
Vol 21 (16) ◽  
pp. 5735 ◽  
Author(s):  
Dariusz Karcz ◽  
Arkadiusz Matwijczuk ◽  
Daniel Kamiński ◽  
Bernadette Creaven ◽  
Ewa Ciszkowicz ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Metal Ion ◽  
Hydroxyl Group ◽  
Moderate Activity ◽  
Spectroscopic Techniques ◽  
Concomitant Treatment ◽  
Bacterial Strains ◽  
Thiadiazole Derivative ◽  
Metal Ratio ◽  
Thiadiazole Derivatives

Classical synthetic protocols were applied for the isolation of three novel 1,3,4-thiadiazole derivatives which were then complexed with the biologically important Cu(II) and Zn(II) ions. All free ligands and their corresponding complexes were characterized using a number of spectroscopic techniques including Ultraviolet-visible (UV–vis), Fluorescence, Infrared (FT-IR), tandem liquid chromatography-mass (LC-MS), X-ray diffraction (XRD), and Nuclear Magnetic Resonance (NMR) spectroscopy (1H, 13C, HSQC, HMBC). The results obtained are consistent with the formation of dihydrate complexes, in which the chelation of the metal ion occurs via one of the thiadiazole nitrogen atoms and the deprotonated hydroxyl group of the neighboring resorcynyl moiety. The Zn(II) complexes utilize a 1:1 ligand–metal ratio, while in the Cu(II) complexes the ligand–metal ratio is 2:1. Although the antibacterial testing identified moderate activity of the compounds against the tested bacterial strains and additionally modest antioxidant activity, a strong synergistic antibacterial effect against Staphylococcus aureus, using concomitant treatment of thiadiazole derivatives with the commercial antibiotic kanamycin, was observed. The most active thiadiazole derivative demonstrated a minimal inhibitory concentration (MIC) of 500 μg/mL while it was 125 μg/mL in the presence of kanamycin. Moreover, in the presence of few thiadiazole derivatives the MIC value of kanamycin decreased from 0.39 μg/mL to 0.5 μg/mL. The antioxidant activity (IC50) of the most active thiadiazole derivative was determined as 0.13 mM which was nearly three-fold lower compared to that of TROLOX (0.5 mM).

Flavonoids and triterpenes from Combretum fragrans with anti-inflammatory, antioxidant and antidiabetic potential

2018 ◽  
Vol 73 (5-6) ◽  
pp. 211-219 ◽  
Author(s):  
Amadou Dawé ◽  
Marius Mbiantcha ◽  
Fawai Yakai ◽  
Almas Jabeen ◽  
Muhammad Shaiq Ali ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Antidiabetic Activity ◽  
Moderate Activity ◽  
Spectroscopic Techniques ◽  
Asiatic Acid ◽  
Anti Inflammatory

Abstract Despite the well-documented benefits of Combretum fragrans in Cameroon, only few scientific works have been done on it. In this study we isolated eight compounds from the leaves extract of C. fragrans: velutin (1), belamcanidin (2), cirsilineol (3), cirsimaritin (4), 3β-acetoxy-20,24-epoxy-11,25-hydroxy-dammarane (5), combretin A (6), combretin B (7) and a mixture of arjunolic acid (8a) and asiatic acid (8b). Compounds 6 and 7 presented potent anti-inflammatory, antioxidant and antidiabetic activities. Compounds 1, 3, 5 and the mixture of 8a and 8b were significantly active, and compounds 2 and 4 presented moderate activity for reactive oxygen species inhibitory and free-radical scavenging. All compounds were isolated using chromatographic techniques; their structures were elucidated by spectroscopic techniques and their spectroscopic data compared with those of the literature. Anti-inflammatory activity was evaluated via the oxidative burst assay using a luminol-amplified chemiluminescence technique, antioxidant activity by free-radical scavenging activity (DPPH) and antidiabetic activity via α-glucosidase inhibition. All of the isolated compounds (1–8) were reported to exhibit significant antioxidant activity. Compounds 1, 3, and 5–8 exhibited potent chemiluminescence inhibition effect, and only compounds 6 and 7 inhibited α-glucosidase. Thus, C. fragrans can be used as an effective natural source of anti-inflammatory, antioxidant and antidiabetic compounds.

scholarly journals Green Synthesis and Antimicrobial Potential of Silver/Gold Nanoparticles Functionalized with Debregeasia salicifolia D. Don

2020 ◽  
Vol 14 (4) ◽  
pp. 2513-2523
Author(s):  
Sami Bawazeer ◽  
Abdur Rauf ◽  
Khaliq Ur Rahman ◽  
Jawad Ali ◽  
Ghias Uddin ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Crude Extract ◽  
Radical Scavenging ◽  
Soluble Starch ◽  
Moderate Activity ◽  
Spectroscopic Techniques ◽  
Bacterial Strains ◽  
Gold And Silver Nanoparticles ◽  
Antibacterial And Antifungal Activities

The aim of the current study was to detect various secondary metabolites in the extract of Debregeasia salicifolia, and to synthesize stable silver/gold nanoparticles (Ag/AuNPs) from D. salicifolia methanol crude extract. The antioxidant, antibacterial, and antifungal activities of the methanol crude extract, various isolated fractions, and the synthesized nanoparticles were evaluated. Phytochemical analyses of the methanol extract/fractions indicated the presence of tannins, saponins, flavonoids, steroids, terpenoids, coumarins, emodins, and soluble starch. Gold and silver nanoparticles have been subsequently synthesized from the methanol crude extract by green synthesis, and characterized by UV and IR spectroscopic techniques. Size of the particles was determined with the aid of an atomic force microscope (AFM). The results revealed that the size of AuNPs was 5-100 nm, and that of AgNPs was in the range 5-100 nm. Bioactivity screening revealed that chloroform and n-hexane fractions exhibited significant 2,2-diphenyl-1-picrylhydrazyl (DPPH·) radical scavenging potential against quercetin. Additionally, the extract/fractions and AuNPs were also subjected to antimicrobial activity screening against a number of strains of microbes. Among extracts, n-hexane fraction showed good antifungal activity as compared to other fractions, whereas in the case of anti-bacterial activity, extract and fractions were active against Gram positive and Gram negative bacterial strain. AuNPs were exhibited moderate activity against all tested bacterial strains.

scholarly journals Synthesis, characterization, and pharmacological evaluation of thiourea derivatives

2020 ◽  
Vol 18 (1) ◽  
pp. 764-777
Author(s):  
Sumaira Naz ◽  
Muhammad Zahoor ◽  
Muhammad Naveed Umar ◽  
Saad Alghamdi ◽  
Muhammad Umar Khayam Sahibzada ◽  
...  
Keyword(s):  
Spectroscopic Techniques ◽  
Organosulfur Compounds ◽  
Bacterial Strains ◽  
Thiourea Derivatives ◽  
Toxicological Effects ◽  
Pharmaceutical Industries ◽  
Uv Visible ◽  
Hematological And Biochemical Parameters

AbstractThioureas and their derivatives are organosulfur compounds having applications in numerous fields such as organic synthesis and pharmaceutical industries. Symmetric thiourea derivatives were synthesized by the reaction of various anilines with CS2. The synthesized compounds were characterized using the UV-visible and nuclear magnetic resonance (NMR) spectroscopic techniques. The compounds were screened for in vitro inhibition of α-amylase, α-glucosidase, acetylcholinesterase (AChE), and butyrylcholinesterase (BuChE) enzymes and for their antibacterial and antioxidant potentials. These compounds were fed to Swiss male albino mice to evaluate their toxicological effects and potential to inhibit glucose-6-phosphatase (G6Pase) inhibition. The antibacterial studies revealed that compound 4 was more active against the selected bacterial strains. Compound 1 was more active against 2,2-diphenyl-1-picrylhydrazyl and 2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals, AChE, BuChE, and α-glucosidase. Compound 2 was more potent against α-amylase and G6Pase. Toxicity studies showed that compound 4 is safe as it exerted no toxic effect on any of the hematological and biochemical parameters or on liver histology of the experimental animals at any studied dose rate. The synthesized compounds showed promising antibacterial and antioxidant potential and were very active (both in vitro and in vivo) against G6Pase and moderately active against the other selected enzymes used in this study.

scholarly journals Spectroscopic Study of the Molecular Structure of the New Hybrid with a Potential Two-Way Antibacterial Effect

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1442
Author(s):  
Dorota Kowalczuk ◽  
Agata Gładysz ◽  
Monika Pitucha ◽  
Daniel M. Kamiński ◽  
Agnieszka Barańska ◽  
...  
Keyword(s):  
Spectroscopic Study ◽  
Good Alternative ◽  
Structure Characterization ◽  
Resonance Spectroscopy ◽  
Spectroscopic Techniques ◽  
Bacterial Strains ◽  
Active Components ◽  
Hybrid Compound ◽  
Coordination Sites ◽  
Almost All

Bacterial strains become resistant to almost all classes of antibiotics, which makes it necessary to look for new substitutes. The non-absorbable ciprofloxacin–biguanide bismuth complex, used locally, may be a good alternative to a conventional therapy. The purpose of this study was to study the structure of the proposed ciprofloxacin (CIP) -bismuth(III)—chlorhexidine (CHX) composite (CIP-Bi-CHX). The spectroscopic techniques such as UV-VIS (ultraviolet-visible) spectroscopy, FTIR (Fourier-transform infrared) spectroscopy and NMR (Nuclear Magnetic Resonance) spectroscopy were used for structure characterization of the hybrid compound. The performed analysis confirmed the presence of the two active components—CIP and CHX and revealed the possible coordination sites of the ligands with bismuth ion in the metallo-organic structure. Spectroscopic study showed that the complexation between Bi(III) and CIP occurs through the carboxylate and ketone groups of the quinolone ring, while CHX combines with the central ion via the biguanide moieties.

scholarly journals Antimicrobial Activity of Cyclic-Monomeric and Dimeric Derivatives of the Snail-Derived Peptide Cm-p5 against Viral and Multidrug-Resistant Bacterial Strains

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 745
Author(s):  
Melaine González-García ◽  
Fidel Morales-Vicente ◽  
Erbio Díaz Pico ◽  
Hilda Garay ◽  
Daniel G. Rivera ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antifungal Activity ◽  
Multidrug Resistant ◽  
Moderate Activity ◽  
Dependent Manner ◽  
Bacterial Strains ◽  
Acinetobacter Baumanii ◽  
Concentration Dependent Manner ◽  
Conventional Antibiotics

Cm-p5 is a snail-derived antimicrobial peptide, which demonstrated antifungal activity against the pathogenic strains of Candida albicans. Previously we synthetized a cyclic monomer as well as a parallel and an antiparallel dimer of Cm-p5 with improved antifungal activity. Considering the alarming increase of microbial resistance to conventional antibiotics, here we evaluated the antimicrobial activity of these derivatives against multiresistant and problematic bacteria and against important viral agents. The three peptides showed a moderate activity against Pseudomonas aeruginosa, Klebsiella pneumoniae Extended Spectrum β-Lactamase (ESBL), and Streptococcus agalactiae, with MIC values > 100 µg/mL. They exerted a considerable activity with MIC values between 25–50 µg/mL against Acinetobacter baumanii and Enterococcus faecium. In addition, the two dimers showed a moderate activity against Pseudomonas aeruginosa PA14. The three Cm-p5 derivatives inhibited a virulent extracellular strain of Mycobacterium tuberculosis, in a dose-dependent manner. Moreover, they inhibited Herpes Simplex Virus 2 (HSV-2) infection in a concentration-dependent manner, but had no effect on infection by the Zika Virus (ZIKV) or pseudoparticles of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). At concentrations of >100 µg/mL, the three new Cm-p5 derivatives showed toxicity on different eukaryotic cells tested. Considering a certain cell toxicity but a potential interesting activity against the multiresistant strains of bacteria and HSV-2, our compounds require future structural optimization.

Aktywność przeciwutleniająca i przeciwbakteryjna miodu, propolisu oraz pyłku kwiatowego

2020 ◽  
Vol 21 (3) ◽  
Author(s):  
Magdalena Woźniak ◽  
Lucyna Mrówczyńska ◽  
Anna Sip ◽  
Marta Babicka ◽  
Tomasz Rogoziński ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Pathogenic Bacteria ◽  
Radical Scavenging Activity ◽  
Colorimetric Method ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Total Content ◽  
Diffusion Method ◽  
Bacterial Strains

Introduction. Honey, propolis and pollen belong to bee products that have beneficial biological properties. These products exhibit e.g. antibacterial, antifungal and antioxidant properties. Due to biological activity and natural origin, bee products are used, e.g. in the food industry, cosmetology and pharmacy. Aim. The aim of the study was to compare the antioxidant and antibacterial activity of honey, propolis and pollen from an apiary located in Wielkopolska Province. Material and methods. Honey, propolis and pollen used in this study came from the same apiary located in Wielkopolska Province. The antioxidant potential of bee products was evaluated applying DPPH· free radical scavenging activity assay. The antimicrobial activity of the tested bee products was determined by the point-diffusion method against 13 strains of pathogenic and potentially pathogenic bacteria. In addition, the total content of phenolic compounds in honey, propolis and pollen was determined by the colorimetric method. Results. Propolis exhibited higher antioxidant activity, in comparison to honey and pollen. The antiradical activity of propolis was equal to 80% approx. activity of Trolox, the standard antioxidant. Among tested bee products, propolis was characterized by the highest total phenols content. In addition, honey, propolis and pollen showed antagonistic activity against tested bacterial strains. Conclusions. The obtained results indicate that among the tested bee products of native origin, i.e. honey, propolis and pollen, propolis characterized by the highest antioxidant activity and the total content of phenolic compounds. In addition, all bee products showed bactericidal activity against the tested bacterial strains.

Cytotoxicity and Antibacterial Studies of Newly Synthesized Novel Heterocylcic Pyridine Derivative and its Metal Complexes

2021 ◽  
Vol 6 (4) ◽  
pp. 243-249
Author(s):  
B.R. Chaitanya Kumar ◽  
K. Sudhakar Babu ◽  
J. Latha
Keyword(s):  
Metal Complexes ◽  
Cell Lines ◽  
Cancer Cell ◽  
Metal Ion ◽  
Analytical Data ◽  
Cancer Cell Lines ◽  
Diffusion Method ◽  
Pyridine Derivative ◽  
Bacterial Strains ◽  
Physico Chemical

A pyridine derivative 2-((E)-1-(2-hydrazinyl-4-methyl-6-phenyl-pyridine-3-carboyl)ethyl)pyridine-4- carbonitrile (CPHPC) ligand and its 3d-metal(II) complexes has been synthesized (where [M = Co(II), Ni(II) and Cu(II)]. The physico-chemical, analytical data, UV-Vis, FT-IR, 1H NMR and ESR spectrum methods were used to characterize all of the synthesized complexes. Spectral investigations of metal(II) complexes revealed that the metal ion is surrounded by an octahedral geometry. Low conductance values indicated that the metal(II) complexes behave as non-electrolyte. The cytotoxic activity on lung cancer cell lines and hepatic cancer cell lines A549 and HepG2, respectively, with the ligand and their metal complexes were tested with MTT assay. The ligand and its metal complexes were tested for diverse harmful bacterial strains using the agar well diffusion method on Gram-negative bacteria such as Pseudomonas desmolyticum, Escherichia coli and Klebsiella aerogenes, as well as Gram-positive bacteria Staphylococcus aureus.

Antioxidant and anticancer activities of an Aporphine alkaloid isolated from Alphonsea sclerocarp

2018 ◽  
Vol 7 (1) ◽  
pp. 51-55
Author(s):  
Suman Joshi DSD ◽  
◽  
Chander Amgoth ◽  
Surya Narayana S ◽  
Padmavathi CH ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Medicinal Plant ◽  
Chronic Myeloid Leukaemia ◽  
Mtt Assay ◽  
Preparative Hplc ◽  
Spectroscopic Techniques ◽  
Anticancer Activities ◽  
Frap Assay ◽  
Aporphine Alkaloid ◽  
Dose Dependent

Herein, we report on the anticancer and antioxidant activity of an Aporphine alkaloid isolated from medicinal plant Alphonsea sclerocarpa. Conventional column chromatography and preparative HPLC methods were used to isolate and purify the alkaloid. Based on NMR, FTIR and MS/MS spectroscopic techniques the compound was identified as Crebanine. This is the first report on the presence of Crebanine from the leaves of Alphonsea sclerocarpa. Antioxidant activity was evaluated using DPPH and FRAP assay. The antioxidant activity was dose-dependent and activity increased with the increase in the concentration. The cytotoxicity assay was carried out using MTT assay. The results showed remarkable cytotoxic activity against K562 (CML-chronic myeloid Leukaemia blood cancer) cells with a % inhibition of 37.545 at 500µm concentration after an incubation of 24h

scholarly journals Synthesis, Modeling Study and Antioxidants Activity of New Heterocycles Derived from 4-Antipyrinyl-2-Chloroacetamidothiazoles

2018 ◽  
Vol 8 (11) ◽  
pp. 2128 ◽  
Author(s):  
Sraa Abu-Melha
Keyword(s):  
Antioxidant Activity ◽  
Dipole Moments ◽  
Ammonium Thiocyanate ◽  
Dft Method ◽  
Basis Sets ◽  
Spectroscopic Techniques ◽  
Mass Analysis ◽  
Antioxidants Activity ◽  
Material Studio ◽  
Properties Of Materials

The present work reports the preparation of twelve new heterocyclic scaffolds containing an antipyrinyl-thiazole hybrid through the reaction of 4-antipyrinyl-2-chloroacetamido-thiazoles 1 and 6 with various types of nucleophiles, namely; ethyl thioglycolate, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, ammonium thiocyanate, malononitrile, and salicylaldehyde. The constructed compounds were characterized by conventional spectroscopic techniques (IR, 1H NMR, 13C NMR, and mass analysis). A DFT method (material studio package) was used to predict the geometry, bond lengths, bond angles, and dipole moments as well as other global chemical reactivities of the constructed antipyrinyl-thiazole compounds. Also, their semi-core pseudopods calculations (dspp) were carried out with DNP (double numerical basis sets plus polarization functional) to predict the properties of materials. In addition, the antioxidant activity of these antipyrinyl-thiazole scaffolds has been screened by the ABTS method. The results indicated that 2-(4-antipyrinylthiazolylamino)-5-substituitedbenzylidene-thiazol-4(5H)-ones 10b and 10c exhibited the best antioxidant activity with a percentage inhibition of 85.74% and 83.51%, respectively.

scholarly journals Zn(II) and Ag(I) complexes of N-allythioamides of pyrimidinyl (cyclohexenyl) carboxylic acids and products their proton- and iodocyclization

2019 ◽  
Vol 85 (3) ◽  
pp. 3-19
Author(s):  
Polina Borovyk ◽  
Mariia Litvinchuk ◽  
Anton Bentya ◽  
Svitlana Orysyk ◽  
Yurii Zborovskiy ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Metal Ion ◽  
Polymer Chains ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Polymer Complexes ◽  
Vis Spectroscopy ◽  
Polynuclear Coordination Compounds ◽  
Complexation Reactions ◽  
Oxygen Atoms

The possibility of using N-allylcarbothioamide derivatives as well as products of their iodine- and proton-initiated electrophilic heterocyclizations as chelating agents in complexation reactions with Zn(II) and Ag(I) ions is shown. Processing of the obtained experimental data showed that N-allythioamides of pyrimidinyl (cyclohexenyl) carboxylic acids H2L1 – H2L3 and their proton- and iodo-cyclization products HL4, HL5 containing four nucleophilic reaction centers (two oxygen atoms of the carbonyl and hydroxyl groups and N-, S-carbothioamide groups or N-atoms of the dihydrothiazole moiety) are polydentate ligands capable of coordinating with metal ions to form stable six-membered chelate metallocycles. A series of new chelating mono-, bi- and polynuclear complexes Zn(II) and Ag (I) of the composition [Zn2L1,32]n, [Zn2(HL1-3)2(CH3COO)2], [Ag2(HL1,3)2]n, [Zn(HL1-3)2], [Ag(H2L3)2NO3], [Zn(HL4,5)2], K[Ag(HL4,5)2] were synthesized and isolated in solid state. Their molecular structure was established by methods of elemental chemical analysis, NMR 1H, IR and UV-Vis spectroscopy. At a ratio of M:L 1:2, complexes were isolated in which two ligand molecules H2L1 − H2L3 are coordinated to the metal ion by the sulfur atoms of the carbothioamide group and the oxygen of the mono-deprotonated hydroxyl group. It was established that the products of the proton-/iodocyclization HL4, HL5 in the complex formation pass into the thione tautomeric form with coordination through the oxygen atoms of the deprotonated hydroxyl group and nitrogen atoms of the dihydrothiazole heterocycle. At M:L 1:1, binuclear or polynuclear coordination compounds are formed. It was shown that polymerisation in complexes [Zn2L1,32]n and [Ag2(HL1,3)2]n is due to the formation of Zn−(O2SN)−Zn and Ag−O−Ag polymer chains. Investigation of the solubility of the resulting complexes showed that the polymer complexes are weakly soluble or insoluble in DMSO, DMF, while the mononuclear are soluble in methanol, as well as in water.

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