Antibacterial Activity Of Compounds Research Articles

Indole-3-carbaldehyde Semicarbazone Derivatives: Synthesis, Characterization, and Antibacterial Activities

Four indole-3-carbaldehyde semicarbazone derivatives, 2-((5-bromo-1H-indol-3-yl)methylene)hydrazinecarboxamide (1), 2-((5-chloro-1H-indol-3-yl)methylene)hydrazinecarboxamide (2), 2-((5-methoxy-1H-indol-3-yl)methylene)hydrazinecarboxamide (3), and 2-((4-nitro-1H-indol-3-yl)methylene)hydrazinecarboxamide (4) were synthesized and characterized by ESI-MS and spectroscopic (FT-IR, 1H NMR, and 13C NMR) techniques. The two-dimensional NMR (in acetone-d6) spectral data revealed that the molecules 1 and 2 in solution are in the cisE isomeric form. This evidence is supported by DFT calculations at the B3LYP/6-311++G(d,p) level of theory where it was shown that the corresponding most stable conformers of the synthesized compounds have a cisE geometrical configuration, in both the gas and liquid (acetone and DMSO) phases. The in vitro antibacterial activity of compounds 1–4 was determined against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria. Among all the tested semicarbazones, 1 and 2 exhibited similar inhibitory activities against Staphylococcus aureus (MIC = 100 and 150 μg/mL, respectively) and Bacillus subtilis (MIC = 100 and 150 μg/mL, respectively). On the other hand, 3 and 4 were relatively less active against the tested bacterial strains compared with 1, 2, and tetracycline.

Phytochemical Screening and Detection of Antibacterial Components from Crude Extracts of Some Armenian Herbs Using TLC-Bioautographic Technique.

The aim of the research was to explore qualitative and quantitative phytochemical constituents of different extracts from Agrimonia eupatoria L., Hypericum alpestre subsp. polygonifolium (Rupr.) Avet. & Takht., Rumex obtusifolius Willd and Sanguisorba officinalis L. and analyze their bioactive constituents using TLC-bioautography technique. In TLC analysis different solvent systems as mobile phases were used in order to make assumptions about the nature of active antibacterial compounds. The highest total phenolic, flavonoid and tannin content was detected in methanol extract of A. eupatoria (358.9µg Gallic acid equivalent per mg dry weight), acetone extract of H. alpestre (216.75µg Quercetin equivalent per mg dry weight) and acetone extract of R. obtusifolius (76.24µg Catechin equivalent per mg dry weight), respectively. TLC-bioautography analysis using mobile phases with different polarity allowed to separate different bands from tested plants methanol and acetone extracts possessing antibacterial activity against Staphylococcus aureus MDC 5233. Thus, it was revealed, that polar compounds could have considerable contribution to the antibacterial activity of acetone and methanol extracts of H. alpestre and R. obtusifolius. It was hypothesized, that complex compounds can be responsible for the antibacterial action of extracts of A. eupatoria and S. officinalis. Based on obtained data, A. eupatoria, H. alpestre, R. obtusifolius and S. officinalis plants can be recommended as sources of new antibacterial agents.

RETRACTED ARTICLE: A fluorescent Zn(II)-containing coordination polymer for antibiotic sensing and treatment activity on periodontal tissue inflammation after orthodontics by inhibiting the growth of Porphyromonas gingivalis

A novel fluorescent zinc(II)-containing coordination polymer {[Zn(DIPT)](NO3)(H2O)3} (1) having the channel-type framework was generated via using rigid three-terminal nitrogenous hetero-ligand 5-(3,5-di(1H-imidazol-1-yl)phenyl)-2H-tetrazole (HDIPT) in solvent thermal reaction. Benefitting from its excellent fluorescent emission along with high water stability, complex 1 shows selective luminescence sensing for sulfonamide antibiotics with high sensitivity in water. In addition, the anti-bacterial activity of compound 1 against Porphuromonas gingivalis (P. gingivalis ATCC 33277) in vitro and in vivo was evaluated. Firstly, the growth curves of P. gingivalis ATCC 33277 was measured after compound 1 treatment for the in vitro activity evaluation. Then, the in vivo protective effect of compound 1 was further explored, the IL-8 and TNF-α level in gingival fluid revealed the excellent inhibitory effect of compound 1 on the inflammatory response. The results acquired via pose scoring software as well as molecular docking indicated that the compound 1 might bind and inhibit the NF-κB protein function, this might provide a latent regulatory mechanism for compound 1.

Investigation of the antimicrobial activity of Bilberry (Vaccinium myrtillus L.) extract against periodontopathic bacteria

ObjectiveThe purpose of this study was to isolate the active antibacterial compounds from Bilberry (Vaccinium myrtillus L.) against periodontopathic bacteria. MethodsThe acetone soluble fraction of Bilberry was extracted from the oil layer by oil/water separation. The extract was then purified by a silica gel open column chromatography. The minimum inhibitory concentration (MIC) of the total extract or purified fractions against bacteria was measured at each step. ResultsThe MIC of the total extract against Porphyromonas gingivalis was 500 μg/mL. The fraction exhibiting antibacterial activity against P. gingivalis was called NU4-TDC, and its MICs against P. gingivalis, Fusobacterium nucleatum, and Prevotella intermedia were 26.0 ± 7.8 μg/mL, 59.0 ± 10.4 μg/mL, and 45.1 ± 16.5 μg/mL, respectively. The MIC against Streptococcus mutans was >62.5 μg/mL. ConclusionBilberry contains antibacterial components against periodontopathic bacteria, such as P. gingivalis, F. nucleatum, and P. intermedia.

Phytochemical investigation of the flowers of Praxelis clematidea (Griseb.) R.M. King & H. Rob

Chemical investigations of the flowers of Praxelis clematidea resulted in the isolation of 12 known compounds (1–12). Their structures were elucidated by extensive spectroscopic studies and chemical evidence. The structure and absolute configuration of 1 was precisely determined by a combination of 2 D NMR and quantum chemical calculations of ECD spectra analysis. Compounds 1, 4, 11 were isolated from the genus Praxelis for the first time, while 1–6, 8–12 were isolated from P. clematidea for the first time. The antibacterial activity of compounds 1, 2, 7, 9 were evaluated.

Antibacterial Evaluation of Novel Substituted Cycloheptaindoles in Staphylococcus and Enterococcus Strains.

Due to emerging resistances against antibiotics there is a strong need to find novel antibacterial agents with a novel structure to prevent early resistance developments. Bisindole compounds with antibacterial activities which formally result from the reaction of an aldehyde with indole motivated to investigate the reaction of a dialdehyde and indole to give novel structures with potential antibacterial activities. Compounds were yielded by chemical synthesis and purified using column chromatography. The antibacterial activity was determined as minimal inhibitory growth activity in cultures of Gram-positive strains of Staphylococcus aureus and Enterococcus species. Cyclohepta[2,3-b]indoles have been yielded in a one-step reaction procedure with indole substitutions at the cycloheptane central core matching a solution for achieving fused novel cycloalkane indoles with functionalized residues of promising biological activity. So far fused cycloalkane indoles have not been available in a one-step procedure and moreover, core functionalizations have been additional challenges. Various indole substitutions have been done to provide a first set of compounds. Substituent-dependent effects have been suggested to influence the antibacterial activity and first compounds were identified with specific Staphylococcus activities and Enterococcus species effects towards Enterococcus faecalis as critical pathogens in the hospital with upcoming resistances against standard antibiotics.

Synthesis of Acridone Base Phenolic Compounds for Antibacterial Activity

Synthesis of Acridone Base Phenolic Compounds for Antibacterial Activity

Assessment of Antioxidant, Antibacterial Activity and Phytoactive Compounds of Aqueous Extracts of Avocado Fruit Peel from Ethiopia

The present study is focused to assess the efficiency of avocado fruit peel waste in different in vitro activities in order to explore the possibility of utilizing waste as a value-added product in various applications. Preliminary phytochemical screening confirmed the presence of alkaloids, flavonoids, phenols, tannins, glycosides, and absence of sterols, saponins, resins, and thiols. Remarkable free radicals scavenging ability was observed in all the tested radicals namely, DPPH.(IC50 = 71.96 ± 0.44 μg/ml), nitric oxide (NO.) (IC50 = 149.46 μg/ml), hydroxyl (.OH) (107.91 ± 3.59 μg/ml), Superoxide (O2.−) (IC50 = 103.05 ± 2.19 μg/ml). In the antibacterial assay, the zone of inhibition was recorded as 9.5 ± 0.5, 12.0 ± 1.21, 7.5 ± 0.35, 6.0 ± 0.5 and 10.0 ± 1.0 for the strains of Escherichia coli, Klebsiella pneumonia, Pseudomonas spp., Staphylococcus aureus, and Bacillus spp. respectively. The Fourier Transform Infrared (FTIR) profiling indicated the existence of resilient functional groups and the gas chromatography–mass spectrometry (GC–MS) profiling was exhibited the presence of eighteen major components highly accountable for its pharmaceutical activities.

Two new alcohol glycosides from the roots of Paeonia intermedia C. A. Meyer

Two new alcohol glycosides, 1-O-β-d-glucopyranosyl-deoxypaeonisuffrone (1) and 9-O-β-d-apiofuranoyl-(1→6)-β-d-glucopyranosyl-xanthoarnol (2), together with eight known compounds (3–10), have been isolated from the dried roots of Paeonia intermedia C. A. Meyer. Their structures were mainly elucidated on the basis of ESIMS, one- and two-dimensional NMR techniques. Antibacterial activities of compounds 1–10 were evaluated, and compounds 9 and 10 showed antibacterial activities against Staphylococcus argenteus CMCC26003 and Escherichia coli CMCC44103.

Pharmacoinformatics-based identification of anti-bacterial catalase-peroxidase enzyme inhibitors

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb). In the present age, due to the rapid increase in antibiotic resistance worldwide, TB has become a major threat to human life. Regardless of significant efforts have been inclined to improve the healthcare systems for improving diagnosis, treatment, and anticipatory measures controlling TB is challenging. To date, there are no such therapeutic chemical agents available to fight or control the bacterial drug-resistance. The catalase-peroxidase enzyme (katG) which encoded by the katG gene of Mtb is most frequently getting mutated and hence promotes Isoniazid resistance by diminishing the normal activity of katG enzyme. In the current study, an effort has been intended to find novel and therapeutically active antibacterial chemical compounds through pharmacoinformatics methodologies. Initially, the five mutant katG were generated by making mutation of Ser315 by Thr, Ile, Arg, Asn, and Gly followed by structural optimizations. About eight thousand small molecules were collected from the Asinex antibacterial library. All molecules were docked to active site of five mutant katG and wild type katG. To narrow down the chemical space several criteria were imposed including, screening for highest binding affinity towards katG proteins, compounds satisfying various criterion of drug-likeliness properties like Lipinski’s rule of five (RO5), Veber’s rule, absorption, distribution, metabolism, and excretion (ADME) profile, and synthetic accessibility. Finally, five molecules were found to be important antibacterial katG inhibitors. All the analyzed parameters suggested that selected molecules are promising in nature. Binding interactions analysis revealed that proposed molecules are efficient enough to form a number of strong binding interactions with katG proteins. Dynamic behavior of the proposed molecules with katG protein was evaluated through 100 ns molecular dynamics (MD) simulation study. Parameters calculated from the MD simulation trajectories adjudged that all molecules can form stable complexes with katG. High binding free energy of all proposed molecules definitely suggested strong affection towards the katG. Hence, it can be concluded that proposed molecules might be used as antibacterial chemical component subjected to experimental validation.

Identification of N-Substituted Triazolo-azetidines as Novel Antibacterials using pDualrep2 HTS Platform.

Antibiotic resistance is a serious constraint to the development of new effective antibacterials. Therefore, the discovery of the new antibacterials remains one of the main challenges in modern medicinal chemistry. This study was undertaken to identify novel molecules with antibacterial activity. Using our unique double-reporter system, in-house large-scale HTS campaign was conducted for the identification of antibacterial potency of small-molecule compounds. The construction allows us to visually assess the underlying mechanism of action. After the initial HTS and rescreen procedure, luciferase assay, C14-test, determination of MIC value and PrestoBlue test were carried out. HTS rounds and rescreen campaign have revealed the antibacterial activity of a series of Nsubstituted triazolo-azetidines and their isosteric derivatives that has not been reported previously. Primary hit-molecule demonstrated a MIC value of 12.5 µg/mL against E. coli Δ tolC with signs of translation blockage and no SOS-response. Translation inhibition (26%, luciferase assay) was achieved at high concentrations up to 160 µg/mL, while no activity was found using C14-test. The compound did not demonstrate cytotoxicity in the PrestoBlue assay against a panel of eukaryotic cells. Within a series of direct structural analogues bearing the same or bioisosteric scaffold, compound 2 was found to have an improved antibacterial potency (MIC=6.25 µg/mL) close to Erythromycin (MIC=2.5-5 µg/mL) against the same strain. In contrast to the parent hit, this compound was more active and selective, and provided a robust IP position. N-substituted triazolo-azetidine scaffold may be used as a versatile starting point for the development of novel active and selective antibacterial compounds.

Antibacterial diketopiperazines from an endophytic fungus Bionectria sp. Y1085.

Two new diketopiperazines (1, 2), one new polyprenol (3), together with 19 known compounds (4-22) were obtained from the EtOAc extract of Bionectria sp. Y1085, an endophytic fungus isolated from the plant Huperzia serrata. Their structures were elucidated by extensive NMR and MS analysis. Bionectin D (1) is a rare diketopiperazine with a single methylthio substitution at the α-carbon of cyclized amino acid residue. The antibacterial activity of compounds was assayed against Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium ATCC 6539, and some metabolites (1, 2, 10, 11, and 14) exhibited evident antibacterial activity.

Antibacterial Activity of a New Flavone Glycoside from the Stems of Holmskioldia sanguinea Retz.

A new flavone glycoside was isolated from ethanolic extract of stem parts of Holmskioldia sanguinea Retz. Its structure was characterized as 3,4′-dihydroxy-5,7-dimethoxyflavone-3-O-β-Dgalactopyranosyl(1→4)-O-β-D-arabinopyranosyl-4′-O-α-L-rhamnopyranoside (1) by colour reactions, chemical degradation and spectroscopic analysis. Antibacterial activity of compound 1 was evaluated against various Gram positive and Gram negative bacteria showing a significant effects.

Green synthesis of bis‐coumarin derivatives using Fe(SD)3 as a catalyst and investigation of their biological activities

AbstractA convenient, practical, green, and environmentally friendly method was developed for the synthesis of biscoumarins and corresponding tetrakis products from the reaction of 4‐hydroxycoumarin and various aldehydes. The bis‐coumarins were synthesized in high yield under mild reaction conditions. Products were obtained in the presence of in situ prepared Fe(SD)3 [Iron(III) dodecyl sulfate] as a combined Lewis acid–surfactant catalyst (LASC) in water in short reaction times. Also, the antibacterial activity of compounds was screened against Pseudomonas aeruginosa and Escherichia coli as Gram‐negative bacteria and Micrococcus luteus and Staphylococcus aureus as Gram‐positive bacterial strains. Products 3g, 3k–l were most active than cefotaxime against E. coli and also compounds 3c and 3g were most active than cefotaxime against S. aureus.

Sonochemical synthesis, structural characterizations and antibacterial activities of biocompatible Copper(II) coordination polymer nanostructures

A new coordination polymer [Cu(μ2-Amp)2]n (1), (HAmp = 2-Amino-4-methylpentanoic acid), has been synthesized and structurally characterized by single crystal X-ray crystallography. It has a two-dimensional structure with hydrogen bonding interactions. In order to control the growth process of compound 1 nanostructures during its sonochemical synthesis, two procedures of diffuse control growth and surface control growth were followed. These samples were characterized by IR spectroscopy, thermogravimetric and differential thermal analyses (TG-DTA), X-ray powder diffraction (XRD), Energy dispersive X-ray spectroscopy (EDAX) and Scanning Electron Microscopy (SEM). Antibacterial activity of compound 1 nanostructures as well as its blocky crystal sample against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was also studied.

Adamantyl pyran-4-one derivatives and their in vitro antiproliferative activity.

Pyran-4-one (maltol, kojic acid and chlorokojic acid 1) esters of adamantan-1-ylacetic acid were prepared through efficient synthetic routes in good yields and evaluated for their in vitro antiproliferative activity on four cancer cell lines: K562 (chronic myelogenous leukemia), HeLa (cervical cancer), Caco-2 (colorectal adenocarcinoma) and NCI-H358 (bronchioalveolar carcinoma). The results indicate that the presence and the position of the adamantyl acyl group or chlorine atom are the necessary requirement for antitumor activity of pyranone systems. Derivatives of kojic acid with either free (compounds 1 and 8) or acylated 5-OH group (compounds 2 and 9) have shown good-to-moderate activity (IC50 values ranging from 13.1 to 43.0μM) on all cell lines. Adamantyl kojic acid derivative 5 with a free OH group on the position 2 showed activity only on the K562 cell line. It seems that removal of halogen or adamantyl unit from position 2 elicits antileukemic activity, as observed in compound 5. The positive influence of the adamantyl unit was also observed on a 3-OH acylated derivative of maltol I which was also selectively active on the same cell line. 5-O-benzylated adamantyl compounds 6 and 7 and unmodified starting pyranones were found to be inactive. Antibacterial activity of compounds was also evaluated on S. aureus ATCC 13709, M. catarrhalis ATCC 23246, E. faecalis ATCC29212 and E. coli TolC-Tn10, but no activity was observed (MIC values 128-256µg/mL).

Activity of antibacterial compounds from Bacillus subtilis against cellular oncoproteins by in silico approach

Abstract The cellular oncoproteins Caspase-3, Caspase-8 and Nuclear Factor-kappa B (NF-κB) are the factors implicated in several cancers. Synthetic and natural compounds were demonstrated to interact with these oncoproteins. Though bacteria are the source of novel compounds including antimicrobial compounds, their anticancer activity remains elusive. Hence in this study, 10 antibacterial compounds of Bacillus subtilis retrieved from the pubchem database and literature were checked for the ability to bind with the chosen oncoproteins in silico. Among those, the compounds Bacilosarcin C, Lipoamicoumacin D and Lipoamicoumacin C showed higher binding GLIDE scores with Caspase-8 (−13.406), Caspase-3 (−9.955) and NF-κB (−8.702) respectively. The strength of hydrogen bond interactions for Bacilosarcin C, Lipoamicoumacin D and Lipoamicoumacin C with the corresponding oncoproteins were 2.62–3.35 A, 2.05 to 3.15 A and 2.59 to 3.21 A respectively. In the binding of these 10 compounds of Bacillus with NF-κB, Thr, Ser and Gly were commonly involved. Similarly, Asn and Phe with Caspase-3 and Arg and Ser with Caspase-8. It is demonstrated that microbial compounds could be used to design novel drugs against oncoproteins to combat cancer.

Phytochemistry and Antibacterial Activity of Cynometra Cauliflora

Here we report the potential of Cynometra cauliflora methanolic leaves extract as potential antibacterial agent against clinical isolated microorganisms. Phytochemical analyses reveal the presence of tannin, flavonoid, saponins, cardiac glycosides and terpenoids. In spot test, antibacterial activity can be observed through the formation of zone inhibition of three types of bacteria only which are at concentration of extract used were 75 mg/mL and 100 mg/mL. The MIC was determined ranging from 6.25 mg/mL to 100 mg/mL. The highest value of MIC showed by MRSA which is 6.25 mg/mL. For MBC test, no antibacterial activity have been observed showed that the extract was bacteriostatic which can inhibit the growth of bacteria at concentration less than 100 mg/mL but not kill the bacteria. The results provide evidence that leaves of C. cauliflora extract might indeed be used as a potential source of effective natural antimicrobial agents in pharmaceutical industries. Our findings suggest that C. cauliflora methanolic leaves extract contains antibacterial active compounds and could be potential antibacterial agent.

Antibacterial activity and bioactive compounds of 50% hydroethanolic extract of Alpinia zerumbet (Pers.) B.L. Burtt & R.M. Sm.

Objective: To evaluate antibacterial activity and the bioactive compounds of 50% hydroethanolic extract of Alpinia zerumbet (A. zerumbet) rhizomes.Methods: Eight reference microbial strains including two Gram-positive bacteria [Staphylococcus aureus (ATCC 29213) and Enterococcus faecalis (ATCC 29212)] and six Gram-negative bacteria [Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATTC 700603), Proteus mirabilis (DMST 8212), Salmonella enterica subsp. enterica serovar Vellore. (ATCC 15611), Shigella flexneri (ATCC 12022) and Pseudomonas aeruginosa (ATCC 27853)], were used to test antimicrobial susceptibility by the broth microdilution method. Bioactive compounds were analyzed by using HPLC.Results: The minimum inhibitory concentration values of A. zerumbet extract were 8 mg/mL for Staphylococcus aureus, Escherichia coli and Shigella flexneri and 16 mg/mL for Enterococcus faecalis and the other four Gram-negative bacilli. HPLC chromatograms revealed that the A. zerumbet extract contained hydroxybenzoic acids, hydroxycinnamic acids and flavonoids. Conclusions: The constituents of A. zerumbet rhizomes could be a potential source of antibacterial compounds, warranting further study of A. zerumbet extract.

A new furan derivative from an endophytic Aspergillus tubingensis of Decaisnea insignis (Griff.) Hook.f. & Thomson

A new furan derivative named 3-(5-oxo-2,5-dihydrofuran-3-yl) propanoic acid (1) was isolated for the first time. Its structure was elucidated by UV, IR, NMR, HR-ESI-MS and the single-crystal X-ray diffraction spectroscopic data. Meanwhile, the antifungal and antibacterial activities of compound 1 was tested, it exhibited potent antifungal activity against Fusarium graminearum with MIC value of 16 µg/mL and medium antibacterial activity against Streptococcus lactis with MIC value of 32 µg/mL.