Antimicrobial Activity Of Compounds Research Articles

A new polyoxygenated farnesylcyclohexenone from Fungus Penicillium sp.

A new polyoxygenated farnesylcyclohexenone, peniginsengin A (1), was isolated from the fermentation of Penicillium sp. YIM PH30003, an endophytic fungus associated with Panax notoginseng (Burk.) F. H. Chen. The structure was assigned based on a combination of 1 D and 2 D NMR and mass spectral data. The cytotoxicity and antimicrobial activities of compound 1 were investigated.

Gelatine based films added with bacteriocins and a flavonoid ester active against food-borne pathogens

Active films, based on food grade gelatine added with bacteriocins and/or the flavonoid ester prunin laurate as antimicrobial compounds, were prepared. The films were characterized by water vapor permeability, mechanical property measurements and scanning electron microscopy. Film antibacterial activity was determined by the agar diffusion and direct contact microplate techniques against Listeria monocytogenes 01/155, Staphylococcus aureus ATCC29213 and Bacillus cereus 1. Physical properties of gelatine films were not significantly affected by active compound incorporation. Antibacterial effect on each strain was dependent on the active compound incorporated into the film, but in all cases a synergistic inhibitory action was observed when both antimicrobial compounds were added. Thus, the results of this study suggest that gelatine based active films here presented could provide an alternative strategy for food biopreservation. This work proposes the elaboration of active films based on food grade gelatine and the addition of enterocins A, B and P synthesized by Enterococcus faecium SM21 and the flavonoid ester, prunin laurate, as antimicrobial active compounds. Films were prepared using a simple and low cost methodology and their application can be adapted to different kinds of food systems. The inclusion of the antimicrobial compounds on the film matrix did not alter their functional properties. The obtained films were active against L. monocytogenes, S. aureus and B. cereus, providing an alternative tool for food preservation, especially in the case of foods susceptible to contamination by these pathogens. Although the inhibitory effect of active films was different for each indicator strain, in all cases a synergistic inhibition effect was observed when both active compounds, ES and PL, were added to gelatine films. This synergistic effect between both antimicrobial compounds offers a novel potential hurdle technology for food preservation.

Antimicrobial activity of compounds from Acanthospermum hispidum DC and Caesalpinia bonduc (L.) ROXB: Beninese plants used by healers against HIV-associated microbial infections

In this study, we have tested alcoholic extracts (60%) from four Beninese plants: Ocimum gratissimum L., Acanthospermum hispidum DC, Caesalpinia bonduc (L) Roxb and Calotropis procera W. T. Aiton. They are used by the healers to prevent opportunistic diseases associated to HIV-AIDS; on six strains such as: Escherichia coli O 157H7, Staphylococcus aureus ATCC 25923 which resist to methicillin (MRSA), Salmonella typhi, Klebsiella pneumonia, Candida albicans ATCC 10231, and Mycobacterium bovis BCG 040812 which cause microbial infections associated with HIV-AIDS. The results show that all the extracts are bacteriostatic and fungistatic but only the hydro-ethanolic extracts of Acanthospermum hispidum (HE2) and of Caesalpinia bonduc (HE3) presented antibiotic power (respectively ap = 2 and ap = 4) on Candida albicans ATCC 10231. The Mycobacterium bovis BCG shown resistance to tested extracts (CMI > 250 µg/mL). The two fungicidal extracts HE2 and HE3 did not show harmful effects on the cells WI–38 with an IC50 > 100 µg/mL for HE2 and IC50 = 50 µg/mL for HE3. The successive bio-guided purifications of extracts HE2 and HE3 permitted isolation of.three antibacterial compounds: Flavanone (M1); stigmasterol (M2); and quercetin (M3). The three isolated compounds possess antibiotic power (ap 31) on tested strains and are not toxic on shrimp larvae (LC50 0.30  0.17 mg/mL). Key words: Microbial infections, HIV-AIDS, Beninese plants, cytotoxic activity, antimicrobial activity, chromatographic methods.

Antimicrobial activity of compounds from Acanthospermum hispidum DC and Caesalpinia bonduc (L.) ROXB: Beninese plants used by healers against HIV-associated microbial infections

Synthesis, Cytotoxic and Anti-bacterial studies of some novel derivatives of N'-[(2E)-3-phenylprop-2-en-1-yl]-2-(quinolin-8-yloxy) acetohydrazideIrfan A Mohammed, E.V.S. Subrahmanyam

Synthesis and antimicrobial activity of 9-o-substituted palmatine derivatives.

A series of new palmatine derivatives with alkyl or alkyl with N-heterocyclic structures were designed and synthesized at C-9-O according to the principle of association. These compounds were characterised by (1)H NMR, (13)C NMR, ESI-MS and elemental analysis, and tested for their antimicrobial activity in vitro to evaluate structure-activity relationships. The results indicated that 9-O-substituted palmatine derivatives exhibit varying degrees of antimicrobial activity. Antibacterial activities of compounds (3a-f) against Gram +ve bacteria increased 2- to 64-fold than that of palmatine. The compounds (3a-f) possessed relatively weaker inhibitory effects against Gram -ve bacteria and fungi than that against Gram +ve bacteria. Antimicrobial activities of compounds (5a-e) are lower than that of compounds (3a-f). Compound 3d showed the highest antimicrobial activity of all the compounds. The LD50 values of compounds (3a-f) decreased as the alkyl side chain was elongated. Compound 3f showed least toxicity.

PHYTOCHEMICAL SCREENING AND IN VITRO ANTIFUNGAL ACTIVITY OF SEVERAL MOROCCAN MEDICINAL PLANTS AGAINST PENICILLIUM ITALICUM, THE CAUSAL AGENT OF CITRUS BLUE MOLD

The aim of this study was to evaluate the antifungal activity of 50 plant species, harvested in different regions of southern Morocco, against Penicillium italicum, the causal agent of citrus blue mold. The in vitro antifungal activity of plant tissue powder was determined using the agar plate method. Our results showed that among the 50 plants tested, the tissue powder of Anvillea radiate and Thymus leptobotrys plants completely inhibited mycelial growth of P. italicum at a concentration of 10% (w/v). Furthermore, the tissue powder of Asteriscus graveolens, Bubonium odorum, Ighermia pinifolia, Inula viscosa, Halimium umbellatum, Hammada scoparia, Rubus ulmifolius, Sanguisorba minor and Ceratonia siliqua plants were also effective against P. italicum with more than 75% inhibition of the mycelial growth. The effect of plant aqueous extracts on spore germination and germ tube elongation varied significantly (P<0.05) between tested plants. Aqueous extracts from A. graveolens, B. odorum and H. umbellatum totally inhibited germination and germ tube elongation of P. italicum conidia at a concentration of 10 mg/ml. Phytochemical analysis of plants with more than 75% inhibitory effect showed the presence of antimicrobial active compounds such as alkaloids, flavonoids, terpenoids, coumarins, tannins and saponosids. These results indicate that these plants contained compounds with antifungal potential against P. italicum. These natural products represent a sustainable alternative to the use of chemical pesticides.

Influence of the Temperature on the Efficiency of Cellulose Treatment Using Copolymer Chitosan-Eugenol

In order to achieve effective antimicrobial protection of textile materials against microorganisms, a natural compound called chitosan has become very interesting. In regard to the antimicrobial protection of textile materials, functionalization with chitosan does not affect some other properties, such as antioxidative or any other action. For this reason, it seems appropriate for chitosan to be combined with any natural antimicrobial active compound, such as eugenol, an extract of clove oil. During this research viscose as a representative of cellulose fibers was used, because it can be functionalized relatively easily. In terms of functionalization, the drying temperature of viscose, after antimicrobial compound application onto substrate, as well as the successful synthesis of copolymer chitosan/eugenol is also important. FTIR spectroscopy was used to evaluate the efficiency of synthesizing a chitosan/eugenol graft copolymer. The spectrophotometric method Acid Orange 7 was chosen as a means for determining the proportion of available antimicrobial active amino groups. In addition, microbiological testing of selected pathogenic micro-organisms was also performed. The results were compared with the results for viscose functionalized by a 1% solution of chitosan.

Antimicrobial sesquiterpenes from the Chinese medicinal plant, Chloranthus angustifolius

Two new eudesmane-type sesquiterpenes, 9α-hydroxycurcolonol (1) and 3α-hydroxy-4-deoxy-5-dehydrocurcolonol (2), along with nine known sesquiterpenes (3–11), were isolated from the roots of Chloranthus angustifolius. The antimicrobial activities of compounds 1–11 were evaluated against five bacteria and six fungal strains. Compounds 6–11 showed potent activities against Candida albicans with MIC values ranging from 4 to 8μg/mL. The structures of the two new compounds 1 and 2 were established by a detailed analysis of their NMR and mass spectroscopic data.

Antimicrobial and antioxidant activities of a new benzamide from endophytic Streptomyces sp. YIM 67086

A new benzamide (1) and four known compounds (2–5) were isolated from endophytic Streptomyces YIM67086, and their structures were determined as 2-amino-3,4-dihydroxy-5-methoxybenzamide (1), 4-hydroxy-3-methoxybenzoic acid (2), phenylacetic acid (3), N-acetyltyramine (4) and p-hydroxytruxinic acid (5). Compound 5 was first found in the microorganism. The antimicrobial activities of compounds 1–5 and antioxidant activity of compound 1 were investigated.

Two new 2,3-seco-hopane triterpene derivatives from Megacodon stylophorus and their antiproliferative and antimicrobial activities.

Chemical investigation of the ethanol extract of the whole plant of Megacodon stylophorus led to the isolation and identification of two new seco-hopane triterpenoids, 2,3-seco-22(29)-hopene-2-carboxyl-3-aldehyde (1) and 2,3-seco-4(23),22(29)-hopene-2-carboxyl-3-aldehyde (2), along with 10 known compounds, 3-12. All the isolates were reported from this plant for the first time. The structures of compounds 1 and 2 were determined by detailed analysis of their spectral data including 1D and 2D NMR. In addition, compound 1 was further analyzed by X-ray crystallography. Compounds 1-3 were evaluated for their in vitro anti-proliferative activities on HeLa, MCF-7, and Hep-G2 tumor cell lines. Compound 2 was active against the three cell lines with IC50 values of 3.6, 7.5, and 13.6 µM, respectively, while compound 1 exhibited cytotoxicity on MCF-7 (IC50 14.0 µM) and HeLa (IC50 18.2 µM) cell lines. Antimicrobial activities of compounds 1-2 (minimum inhibitory concentration values in the range of 3.12-12.50 mg/mL) were also observed.

Biological activity of Ganoderma lucidum basidiocarps cultivated on alternative and commercial substrate

Ethnopharmacological relevanceGanoderma lucidum (W. Curt.:Fr.) P. Karst. has been used for several thousand years in traditional medicine of the Far East for the treatment of a various diseases including: cancer, immunological disorders, hepatitis, arthritis, nephritis, bronchitis, asthma etc. Ganoderma species are natural sources of various antimicrobial, antioxidant and antitumor active compounds which can be alternative to commercial antibiotics, antimycotics, antioxidants and cytostatics. As the amount of wild Ganoderma lucidum basidiocarps is not sufficient, the aim of this study was to compare the bioactivity of basidiaocarps obtained on alternative substrate (wheat straw) with commercially cultivated ones. Materials and methodsAntimicrobial potential of the tested Ganoderma lucidum extracts was studied by disc-diffusion and microdilution method. Cytotoxic effect of tested extracts on two cancer cell lines was determined by microculture tetrazolium test. DPPH scavenging ability, total phenols and flavonoids content were measured in order to determine the antioxidative potential of Ganoderma lucidum extracts. ResultsGanoderma lucidum BEOFB 434 extract was the most effective antibacterial agent, while commercial strain was the weakest. DPPH scavenging activity of extracts of basidiocarps from alternative substrate was also significantly higher than that of commercially obtained basidiocarps. The extracts of Ganoderma lucidum BEOFB 431 exhibited the strongest cytotoxic activity significantly higher than those in commercial strain. ConclusionThe study showed that fruiting bodies produced on one of the most accessible and cheapest crop residue, wheat straw, are better antimicrobial, antioxidant and cytotoxic agents than those obtained on conventional substrate, oak sawdust.

English

The antimicrobial activity of bee honey is one of its most studied biological properties, with an extensive spectrum of activity against medically important microorganisms. The specificity of this activity depends on the components of the honey, which vary according to its floral and entomological origin. The action mechanisms of the most transcendental compounds for honey antimicrobial activity; acidity, osmolarity and hydrogen peroxide, are reported. Recent studies have demonstrated the existence of other compounds contributing to the antimicrobial activity of honey such as, enzymes, antimicrobial peptides, phenolic compounds and Methylglyoxal. This article describes both the most important therapeutic properties and the components attributing antimicrobial activity to bee honey, as well as the microorganisms which this effect has been evaluated and their respective minimum inhibitory concentration (MIC). In conclusion, it has been demonstrated that the antimicrobial activity and other biological activities of bee honey such as antitumor, anti-inflammatory, antioxidant and antiviral properties are conferred by a group of components intrinsic to honey and it depends of the botanical, geographical and entomological origin of the honey. Key words: Bee honey, antibacterial activity, minimum inhibitory concentration (MIC).

A new cyclic tetrapeptide from an endophytic Streptomyces sp. YIM67005

One new cyclic tetrapeptide, cyclo(l-Tyr-l-Pro-l-Phe-trans-4-hydroxy-l-Pro) (1), together with two known cyclodipeptides, cyclo(l-Phe-trans-4-hydroxy-l-Pro) (2) and cyclo(l-Val-l-Tyr) (3), were isolated from the fermentation broth of Streptomyces sp. YIM67005 associated with Inula cappa DC. The planar structure of compound 1 was determined on the basis of spectroscopic techniques, while the absolute configurations of the amino acid residues were determined by the application of the advanced Marfey method. The cytotoxicity and antimicrobial activity of compound 1 were investigated.

Synthesis and Biological Activity of 5-aryl-4-acyl-3-hydroxy-1-(2-piperazin-1-ylethyl)-2,5-dihydropyrrol-2-ones and their Derivatives

5-Aryl-4-acyl-3-hydroxy-1-(2-piperazin-1-ylethyl)-2,5-dihydropyrrol-2-ones (I) were synthesized by reactions of acylpyruvate methyl esters with a mixture of aromatic aldehyde and 2-(1-piperazino)-1-ethylamine. Then, the corresponding hydrochlorides (II) were obtained. Compounds I were transformed into 3,4-diaryl-4,6-dihydro-5-(2-piperazin-1-ylethyl)pyrrolo[3,4-c]pyrazol-6-ones (III) by reaction with hydrazine hydrate. The antimicrobial activity of compounds I and the influence of compounds II and III on blood coagulation were studied. The acute toxicity of two compounds was evaluated.

Mono- and bis-furanone derivatives from the endolichenic fungus Peziza sp.

Seven new mono- and bis-furanones, pezizolides A–G (1–7), have been isolated from the crude extract of the endolichenic fungus Peziza sp. inhabiting the lichen Xanthoparmelia sp. The structures of the new compounds were elucidated mainly by NMR and MS methods. The absolute configuration of 1–4 was assigned by the application of CD exciton chirality method, and 1 was further supported by electronic circular dichroism (ECD) calculations, whereas that of 5 was deduced by Snatzke's method following the relative configuration analysis of its acetonide. The cytotoxity and antimicrobial activity of compounds 1–7 were tested.

“Green synthesis” of benzothiazepine library of indeno analogues and their in vitro antimicrobial activity

AbstractA novel series of indeno-benzothiazepine derivatives was synthesised via a “green” route. Synthesis of these compounds involves the treatment of dinucleophiles such as 2-aminobenzenethiols with α,β-unsaturated ketones in poly(oxyethylene) (poly(ethylene glycol), PEG-400) catalysed by acetic acid. The synthone α,β-unsaturated ketones were obtained by Claisen-Schmidt condensation of indan-1-one with substituted pyrazole-2-carbaldehydes prompted by bleaching earth (pH 12.5) as catalyst and PEG-400 as “green” reaction solvent. Screening of all the synthesised compounds for antimicrobial activity revealed that most of these compounds exhibited moderate to significant antimicrobial activity.

First Chemical Constituents from Cordia exaltata Lam and Antimicrobial Activity of Two Neolignans

The phytochemical study of Cordia exaltata Lam. (Boraginaceae) led to the isolation, through chromatographic techniques, of nineteen secondary metabolites: 8,8'dimethyl-3,4,3',4'-dimethylenedioxy-7-oxo-2,7'cyclolignan (1), 8,8'-dimethyl-4,5-dimethoxy-3',4'-methylenodioxy-7-oxo-2,7'cyclolignan (2), sitosterol (3a), stigmasterol (3b), sitosterol-3-O-β-d-glucopyranoside (4a), stigmasterol-3-O-β-d-glucopyranoside (4b), phaeophytin A (5), 132-hydroxyphaeophytin A (6), 173-ethoxypheophorbide A (7), 132-hydroxy-173-ethoxypheophorbide A (8), m-methoxy-p-hydroxybenzaldehyde (9), (E)-7-(3,4-dihydroxyphenyl)-7-propenoic acid (10), 1-benzopyran-2-one (11), 7-hydroxy-1-benzopyran-2-one (12), 2,5-bis-(3',4'-methylenedioxiphenyl)-3,4-dimethyltetrahydrofuran (13), 3,4,5,3',5'-pentamethoxy-1'-allyl-8.O.4'-neolignan (14), 3,5,7,3',4'-pentahydroxyflavonol (15),5,7-dihydroxy-4'-methoxyflavone (16), 5,8-dihydroxy-7,4’-dimethoxyflavone (17), kaempherol 3-O-β-d-glucosyl-6''-α-L-ramnopyranoside (18) and kaempherol 3,7-di-O-α-l-ramnopyranoside (19). Their structures were identified by 1H and 13C-NMR using one and two-dimensional techniques. In addition, the antimicrobial activity of compounds 1, 2, 13 and 14 against bacteria and fungi are reported here for the first time.

Synthesis, Antimicrobial Activities and Molecular Docking Studies of Novel 6-Hydroxybenzofuran-3(2H)-one Based 2,4-Disubstituted 1,3- Thiazoles

Synthesis, characterization and investigation of antibacterial and antifungal activities of thirteen novel 6- hydroxybenzofuran-3(2H)-one based 2,4-disubstituted 1,3-thiazoles are presented. Their structures were determined using NMR, FAB MS and HRMS analyses. The results of microbiological screening reveal that three derivatives containing fluorine, bromine and hydrogen substituents at the phenyl ring are the most active antimicrobial compounds. Molecular docking studies of all compounds on the active sites of microbial enzymes indicated a possible target Nmyristoyltransferase (NMT).

Aug-MIA-QSAR modeling of antimicrobial activities and design of multi-target anilide derivatives

The antibacterial activity against Bacillus subtilis, Staphylococcus aureus and Escherichia coli, as well as the antifungal activity against Aspergillus niger of a series of anilide derivatives have been modeled using augmented multivariate image analysis applied to quantitative structure–activity relationship (aug-MIA-QSAR). This QSAR approach is based on 2D molecular shape, as well as atomic sizes and colors to encode chemical, physical and biological properties. Predictive models with r2 from 0.65 to 0.83 were used to estimate the antimicrobial activities of novel anilide analogs, which were built from the combination of substructures of the most active antimicrobial compounds along the series. Given the synergistic effect of different substituents to provide new molecules, promising compounds were proposed, highlighting a considerable multi-antimicrobial activity.

Antimicrobial effect of blueberry (Vaccinium corymbosum L.) extracts against the growth of Listeria monocytogenes and Salmonella Enteritidis

This study examined the antimicrobial effect of blueberry (Vaccinium corymbosum L.) extracts obtained from four cultivars (Elliott, Darrow, Bluecrop, and Duke) on the growth of Listeria monocytogenes and Salmonella Enteritidis. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the extracts against L. monocytogenes and S. Enteritidis in tryptic soy broth were determined. Concentrations of total phenolic compounds and four individual phenolic (chlorogenic acid, ellagic acid, quercetin, and quercetin-3-galactoside) in the extracts were determined using Folin-Ciocalteau method and HPLC analysis, respectively. All four extracts at 112.5–900 mg/mL exhibited a dose-dependent growth-inhibitory effect against L. monocytogenes and S. Enteritidis. L. monocytogenes was significantly more sensitive to the antimicrobial effect of the extracts than S. Enteritidis. Phenolic compounds in the extracts such as chlorogenic acid, quercetin, ellagic acid, and quercetin-3-galactoside were the active antimicrobial compounds in the blueberry extracts. The results of this study suggest that blueberry extract or extract-derived components may be used to control pathogenic microorganisms. More studies on the use of blueberry as a natural antimicrobial in food products are warranted.