Synthesis, Anti-Inflammatory Activity, and in Vitro Antitumor Effect of a Novel Class of Cyclooxygenase Inhibitors: 4-(Aryloyl)phenyl Methyl Sulfones

Following our previous research on anti-inflammatory drugs (NSAIDs), we report on the design and synthesis of 4-(aryloyl)phenyl methyl sulfones. These substances were characterized for their capacity to inhibit cyclooxygenase (COX-1 and COX-2) isoenzymes. Molecular modeling studies showed that the methylsulfone group of these compounds was inserted deep in the pocket of the human COX-2 binding site, in an orientation that precludes hydrogen bonding with Arg120, Ser353, and Tyr355 through their oxygen atoms. The N-arylindole 33 was the most potent inhibitor of COX-2 and also the most selective (COX-1/COX-2 IC(50) ratio was 262). The indole derivative 33 was further tested in vivo for its ant…

Antimicrobial peptides from echinoderms as antibiofilm agents: a natural strategy to combat bacterial infections

AbstractIncreased attention has been focused on marine invertebrates as a source of bioactive molecules for biomedical applications. Many bioactive molecules are part of the innate immune system. Some more recently isolated compounds, mainly from the sea urchin and the sea cucumber, are antimicrobial peptides (AMPs) active against Gram-positive and Gram-negative bacteria, and fungi. In this review we described the most recent studies on AMPs isolated from echinoderms. AMPs are small peptides (< 10 kDa) with cationic charge and amphipathic structure. Recently, it was demonstrated that in the coelomocyte lysates of Paracentrotus lividus and Holothuria tubulosa, AMPs possess activity against s…

Thiazole Analogues of the Marine Alkaloid Nortopsentin as Inhibitors of Bacterial Biofilm Formation

Anti-virulence strategy is currently considered a promising approach to overcome the global threat of the antibiotic resistance. Among different bacterial virulence factors, the biofilm formation is recognized as one of the most relevant. Considering the high and growing percentage of multi-drug resistant infections that are biofilm-mediated, new therapeutic agents capable of counteracting the formation of biofilms are urgently required. In this scenario, a new series of 18 thiazole derivatives was efficiently synthesized and evaluated for its ability to inhibit biofilm formation against the Gram-positive bacterial reference strains Staphylococcus aureus ATCC 25923 and S. aureus ATCC 6538 a…

Curcumin derivatives as inhibitors of Gram positive and Gram negative biofilm formation

Anti-adhesion agents against Gram-positive pathogens

The rise of antibiotic-resistance as well as the deficiency of investments by pharmaceutical companies in the development of new antibiotics, have stimulated the investigation of alternative strategies to conventional antibiotics for counteracting the pathogens. A fundamental step of Gram positive pathogenesis is the bacterial adhesion to the host tissue involving a direct and a specific interaction between bacterial surface molecules and host ligands. Targeting the adhesion is a good strategy to design novel anti-infective drugs agents useful to interfere with the pathogenic process and with a virulence mechanism as biofilm formation. This review is focused on anti-virulence compounds whic…

SCO5208 encodes the histidinol phosphate phosphatase involved in histidine biosynthesis in Streptomyces coelicolor

FRAGMENTS OF BETA-THYMOSIN FROM THE SEA-URCHIN PARACENTROTUS LIVIDUS AS NOVEL ANTIMICROBIAL PEPTIDES AGAINST STAPHYLOCOCCAL BIOFILMS

With the aim to face the threat of pathogen biofilms intrinsically resistant to conventional antibiotics, we focused on coelomocytes, the immune mediators in echinoderms, as source of novel antimicrobial peptides (AMPs). The proteic fraction <5kDa from coelomocytes cytosol of the sea-urchin Paracentrotus lividus (5-CC) was tested against a group of Gram positive and Gram negative pathogen reference strains. The 5-CC of P. lividus resulted active against all tested strains at concentrations ranging from 15.8 to 253.7 mg/mL. The ability to prevent staphylococcal biofilm formation was evaluated against the biofilm of clinical strain S.epidermidis 1457 using live/dead staining in combination wi…

Paracentrin1, a synthetic antimicrobial peptide fragment of a beta-thymosin from the sea-urchin Paracentrotus lividus, interferes whith staphylococcal and Pseudomonas aeruginosa biofilm formation

Pyrrolomycins as novel agents against staphylococcal biofilms

Synthesis and COX inhibition of 7-R1-8-R2-1-ethyl-3,4-dimethyl-, 4,10-dihydro-1H-pyrazolo[3,4-c][1,5]benzodiazocine-5,11-diones

The title compounds were easily synthesized by reacting the 4-aminopyrazole hydrochloride 2 and the substituted 2-nitrobenzoyl chlorides 3a-d. The obtained 2-nitrobenzamides 4a-d were methylated and then reduced to give the corresponding amines 6a-d. These were hydrolyzed then directly converted into 4,10-dihydro-1H-pyrazolo[3,4-c][1,5]benzodiazocine-5,11-diones 1a-d by the action of SOCl2 in benzene. These were tested for their COX inhibitory activity, showing an inhibitory profile against both COX-1 and COX-2, being slightly more selective against COX-2 with a percentage of inhibition, at the concentration of 10 μM, in the range 42.0 – 55.0.

In Vitro Antimicrobial Activity of Frankincense Oils from Boswellia sacra Grown in Different Locations of the Dhofar Region (Oman)

Frankincense essential oils from Boswellia sacra have been commonly used to treat microbial infections from as early as the 11th century. The main feature of the plant is its gum resin, from which it is possible to obtain essential oils. In the present study, we focused on the comparative study of the oils extracted from the resins of three different Boswellia sacra cultivars (Najdi, Sahli and Houjri). From each of frankincense resin three successive essential oil samples (Grade 1, Grade 2, Grade 3) were obtained. Houjri gum resin gave the lowest percentage (5%) of total essential oil content but showed the maximum number of volatile components in all three grades. Najdi Grade 2 essential o…

Polyanion–tobramycin nanocomplexes into functional microparticles for the treatment of Pseudomonas aeruginosa infections in cystic fibrosis

Aim: Efficacy of antibiotics in cystic fibrosis (CF) is compromised by the poor penetration through mucus barrier. This work proposes a new ‘nano-into-micro’ approach, used to obtain a combinatorial effect: achieve a sustained delivery of tobramycin and overcome mucus barrier. Methods: Mannitol microparticles (MPs) were loaded with a tobramycin polymeric nanocomplex and characterized in presence of CF artificial mucus. Results &amp; discussion: MPs are able to alter the rheological properties of CF artificial mucus, enhancing drug penetration into it and allowing a prolonged drug release. MPs resulted to be effective in Pseudomonas aeruginosa infections if compared with free tobramycin. Co…

Novel antimicrobial and anti-biofilm agents from a marine invertebrate

N-(INDAZOLYL)BENZAMIDO DERIVATIVES AS CDK1 INHIBITORS: DESIGN, SYNTHESIS, BIOLOGICAL ACTIVITY, AND MOLECULAR DOCKING STUDIES

A series of N-1H-indazole-1-carboxamides has been synthesized and their effects on both CDK1/cyclin B and the K-562 (human chronic myelogenus leukemia) cell line were evaluated. Using a computational model, we have observed that all the most active compounds 9e, f, i-n exhibited the same binding mode of purvanalol A in the ATP-binding cleft. Although they were able to moderately inhibit the leukemic cell line K-562 and to show inhibitory activity against the Cdc2-Cyclin B kinase in the low micromolar range, they turned out to be non-cytotoxic against HuDe (IZSL) primary cell cultures from human derm. These preliminary results are quite encouraging in view of the low toxicity demonstrated by…

Synthesis and biological evaluation of some new 2-phenylpropiolamidobenzamides as potential antagonists of the HDM2-p53 protein-protein interactions

Novel Sortase A Inhibitors to Counteract Gram-Positive Bacterial Biofilms

Sortase A (SrtA) is a membrane enzyme responsible for the covalent anchoring of surface proteins on the cell wall of Gram-positive bacteria. Nowadays it is considered an interesting target for the development of new anti-infective drugs which aim to interfere with important Gram-positive virulence mechanisms. Along the years, we studied the anti-staphylococcal and anti-biofilm activity of some natural and synthetic polyhalogenated pyrrolic compounds, called pyrrolomycins. Some of them were active on Gram-positive pathogens at a μg/mL range of concentration (1.5-0.045 μg/mL) and showed a biofilm inhibition in the range of 50-80%. [1-3] In light of these encouraging results, herein we present…

Novel chemical countermeasures against staphylococcal biofilms

Some natural and synthetic related pyrrolomycins, a family of halogenated pyrrole antibiotics, showed anti-biofilm properties in vitro at low concentration (0.045μg/mL) against preformed staphylococcal biofilms. Moreover, considering the human cell toxicity, the selectivity indexes (ratio of cytotoxicity to antibiofilm activity) of some of them were very interesting. The present study aims to investigate if the pyrrolomycins could also prevent staphylococcal biofilm formation. The evaluation of S.aureus ATCC 25923 biofilm formation inhibition was conducted by safranin staining method. At tested concentrations of 0.18, 0.09, 0.045 μg/mL (concentrations much lower than MIC value determined on…

Applicazioni biotecnologiche di batteri del suolo

Synthesis and biofilm formation reduction of pyrazole-4-carboxamide derivatives in some Staphylococcus aureus strains

The ability of several N-phenyl-1H-pyrazole-4-carboxamide derivatives and other pyrazoles opportunely modified at the positions 3, 4 and 5, to reduce the formation of the biofilm in some Staphylococcus aureus strains (ATCC 29213, ATCC 25923 and ATCC 6538) were investigated. All the tested compounds were able, although to a different extent, to reduce the biofilm formation of the three bacterial strains considered. Among these, the 1-(2,5-dichlorophenyl)-5-methyl-N-phenyl-1H-pyrazole-4-carboxamide 14 resulted as the best inhibitor of biofilm formation showing an IC50 ranging from 2.3 to 32 μM, against all the three strains of S. aureus. Compound 14 also shows a good protective effect in vivo…

SYNTHESIS AND BIOLOGICAL EVALUATION OF 2-PHENYL-3-[INDAZOL-3-YL]-4(3H)-QUINAZOLINONES

Pharmaceutical potential of synthetic and natural pyrrolomycins

The emergence of antibiotic resistance is currently considered one of the most important global health problem. The continuous onset of multidrug-resistant Gram-positive and Gram-negative bacterial strains limits the clinical efficacy of most of the marketed antibiotics. Therefore, there is an urgent need for new antibiotics. Pyrrolomycins are a class of biologically active compounds that exhibit a broad spectrum of biological activities, including antibacterial, antifungal, anthelmintic, antiproliferative, insecticidal, and acaricidal activities. In this review we focus on the antibacterial activity and antibiofilm activity of pyrrolomycins against Gram-positive and Gram-negative pathogens…

Pyrazolobenzotriazinones Derivatives as COX Inhibitors: Synthesis Biological Activity and Molecular Modeling Studies

Pyrazolylbenzotriazinones are endowed with structural analogy with the COX-2 selective inhibitor celecoxib. Considering that our research group has long been interested in the 3-pyrazolyl-substituted benzotriazinones as anti-inflammatory agents, six new pyrazolylbenzotriazinone derivatives 16a-c and 18a-c have been prepared by reacting the opportune ethyl 5-(2-aminobenzamido)-1-(pyridin-2-yl)-1H-pyrazole-4-carboxylate or 5-(2-aminobenzamido)-1-(pyridin-2-yl)-1H-pyrazole-4-carboxyic acid with sodium nitrite in glacial acetic acid. The biological studies revealed a good pharmacological profile for some pyrazolylbenzotriazinones and, in the case of the ethyl 5-(4-oxo-1,2,3-benzotriazin-3(4H)-y…

Synthesis and biological evaluation of new indazole derivatives

New N-methyl and N-ethyl substitutions in the indazole nucleus are reported by reacting 3-(2-aminobenzamido)indazole and the appropriate trimethyl/triethyl orthobenzoate. Single crystal X-ray analysis confirms the N-ethylation position for the 3-(1-ethyl-1H-indazol-3-yl)-2-phenylquinazolin-4(3H)-one derivative 3f. Compounds 11a-d and 3a-d were tested to evaluate their antimicrobial, their antiproliferative activity and their COX inhibitory activities showing scarce or moderately antiproliferative activity and some inhibitory activity against COX-1 and COX-2.

2-cinnamamido, 2-(3-phenylpropiolamido) and 2-(3-phenylpropanamido)benzamides: synthesis, antiproliferative activity and mechanism of action

Several new 2-cinnamamido, 2-(3-phenylpropiolamido) and 2-(3-phenylpropanamido)benzamides were synthesized by stirring in pyridine the opportune acid chlorides with the appropriate anthranilamide derivatives. Some of the synthesized compounds were evaluated for their in vitro antiproliferative activity against a panel of 5 human cell lines (K562 human chronic myelogenous leukemia cells, MCF-7 breast cancer cells, HTC-116 and HT26 colon cancer cells and NCI H460 non-small cell lung cancer cells).

Amino acid biosynthesis in Streptomyces coelicolor

Synthesis and anti-staphylococcal activity of new 4-diazopyrazole derivatives.

Abstract Several new 4-diazopyrazole derivatives 6a – g and 9a – c were obtained by the reaction of 1-(R-substituted-phenyl)-3-(1,3-dimethyl-1 H -pyrazol-5-yl)ureas 5a – g and N -(1,3-dimethyl-1 H -pyrazol-5-yl)-2-(R-substituted-phenyl)acetamides 8a – c respectively with a sevenfold excess of nitrous acid in acetic acid solution. The compounds were assayed for their activity against the Staphylococcus aureus reference strains ATCC 25923, ATCC 29213 and ATCC 6538, as well as six veterinary strains. The best anti-staphylococcal profile was showed by [(R-substituted-phenyl)acetyl](4-diazonio-1,3-dimethyl-1 H -pyrazol-5-yl)azanides 9a , c . Compound 9c was also able at 3.1 μg mL −1 to inhibit o…

Design, sinthesis and anticancer properties of new cdks inhibitors

Synthesis, antiproliferative activity, and mechanism of action of new benzamido derivatives

The cinnamoyl anthranilamides represent a class of biological active substances of great importance in medicinal chemistry. Moreover, despite their wide range of biological activities, a review of the literature revealed that no anticancer activity is described for this kind of substances. Starting from the 2-cinnamamido-5-iodobenzamide, resulted able to inhibit the leukemic cell line K-562 proliferation with a percent of inhibition of 74% at 10M concentration, we undertake the following structural modifications on cinnamamidobenzamide skeleton: the introduction of various substituents both on the benzamido and the cinnamamido moieties, the substitution of olefinic bond with the ethane, et…

ChemInform Abstract: Pyrazolo[3,4-d]pyrimidine Derivatives as COX-2 Selective Inhibitors: Synthesis and Molecular Modelling Studies.

The pyrazolo[3,4-d]pyrimidine system shows a multitude of interesting pharmacological properties. Owing to the potential anti-inflammatory activity of 5-benzamido-pyrazolo[3,4-d]pyrimidin-4-one derivatives and considering the easy synthesis of this class of compounds, a set of new 5-benzamido-1H-pyrazolo[3,4-d]pyrimidin-4-ones has been prepared in 42-80% yields by reacting 5-aminopyrazole-4(N-benzoyl)carbohydrazide derivatives and the opportune triethylorthoesters. Compounds 8a, b, 10a-d, and 11a, b revealed a superior inhibitory profile against COX-2, when compared to that of reference standards NS398 and indomethacin. Molecular modelling studies confirmed the obtained biological results.

Fragments of β-thymosin from the sea urchinParacentrotus lividusas potential antimicrobial peptides against staphylococcal biofilms

The immune mediators in echinoderms can be a potential source of novel antimicrobial peptides (AMPs) applied toward controlling pathogenic staphylococcal biofilms that are intrinsically resistant to conventional antibiotics. The peptide fraction <5 kDa from the cytosol of coelomocytes of the sea urchin Paracentrotus lividus (5-CC) was tested against a group of Gram-positive and Gram-negative pathogen reference strains. The 5-CC of P. lividus was active against all planktonic-tested strains but also showed antibiofilm properties against staphylococcal strains. Additionally, we demonstrated the presence of three small peptides in the 5-CC belonging to segment 9-41 of a P. lividusβ-thymosin. T…

It is Time for Action in the Struggle against Antibiotic-Resistance, Let’s Start Reducing or Replacing Antibiotics in Agriculture

Million people around the world are infected each year and thousands of them die from pathogens that are resistant to the treatment by any of known antibiotics [1]. The excessive use and abuse of antibiotics in clinical setting and in agriculture, added to the great ability of microorganisms to evolve, are the causes of the wide spread of isolates resistant to all major classes of current antibiotics. It is time for action in order to tackle antimicrobial-resistance (AMR), which can be considered a major threat to global health care and security. While we are waiting for new antimicrobial molecules and strategies, shorter-term approaches are needed to address the menace of AMR and preserve …

The gut bacterial community of the red palm weevil Rhynchophorus ferrugineus (Olivier, Coleoptera, Curculionidae) larvae

The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier, Coleoptera, Curculionidae) is the major pest of palm trees in the Mediterranean area. Damages are caused mainly by the endophytophagous larvae that consume the palm tender soft tissues making galleries and producing a wet “frass” with a characteristic fermented odour. The culturable bacterial community associated to the frass produced by RPW larvae inside Phoenix canariensis trees is mainly composed of facultative anaerobe gamma-proteobacteria that have their closest phylogenetic relatives in the gut microbiome of other endophytophagous and xilophagous coleopteran as bark beetles and other plant biomass-degrading insects (leaf-c…

Oregano essential oils activity against Listeria monocitogenes biofilms

Synthesis and antioproliferative activity of new derivatives containing the policyclic sistem 5,7:7,13-dimethanopyrazolo[3,4-b]pyrazolo[3'.4':2,3]azepino[4,5-f]azocine

By reacting methylaminopyrazoles with hexane-2,5-dione in 1,4-dioxane in the presence of p-toluensulfonic acid, new derivatives containing the policyclic sistem 5,7:7,13-dimethanopyrazolo[3,4-b]pyrazolo[3'.4':2,3]azepino[4,5-f]azocine were obtained. The new synthesized compounds were tested preliminarly at 10 microM against five human cancer cell lines showing a range of inhibition of 20-62% against the most susceptible cell lines K562 and HCT116.

Synthesis, antiproliferative activity and possible mechanism of action of novel 2-acetamidobenzamides bearing the 2-phenoxy functionality.

Several new 2-(2-phenoxyacetamido)benzamides 17a-v, 21 and 22 were synthesized by stirring in pyridine the acid chlorides 16a-e and the appropriate5-R-4-R1-2-aminobenzamide 15a-e and initially evaluated in vitro for antiproliferative activity against the K562 (human chronic myelogenous leukemia) cell line. Some of synthesized compounds were evaluated for their in vitro antiproliferative activity against the full NCI tumor cell line panel derived from nine clinically isolated cancer types (leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate and breast). The most active compounds caused an arrest of K562 cells in the G0-G1 phase of cell cycle and induction of apoptos…

Discovery of a new class of sortase a transpeptidase inhibitors to tackle gram-positive pathogens: 2-(2-phenylhydrazinylidene)alkanoic acids and related derivatives

A FRET-based random screening assay was used to generate hit compounds as sortase A inhibitors that allowed us to identify ethyl 3-oxo-2-(2-phenylhydrazinylidene)butanoate as an example of a new class of sortase A inhibitors. Other analogues were generated by changing the ethoxycarbonyl function for a carboxy, cyano or amide group, or introducing substituents in the phenyl ring of the ester and acid derivatives. The most active derivative found was 3-oxo-2-(2-(3,4dichlorophenyl)hydrazinylidene)butanoic acid (2b), showing an IC50 value of 50 µM. For a preliminary assessment of their antivirulence properties the new derivatives were tested for their antibiofilm activity. The most active compo…

Paracentrin 1, a synthetic antimicrobial peptide fragment of a beta-thymosin from the sea-urchin Paracentrotus lividus, interferes with staphylococcal and Pseudomonas aeruginosa biofilm formation

Synthesis and antiproliferative activity of new derivatives containing the polycyclic system 5,7:7,13-dimethanopyrazolo[3,4-b]pyrazolo[3’,4’:2,3]azepino[4,5-f]azocine

The reaction under reflux between 1-phenyl-3-R-5-methylaminopyrazoles and 2,5-hexanedione lead to 5,7:7,13-dimethanopyrazolo[3,4-b]pyrazolo[3′,4′:2,3]azepino[4,5-f]azocine derivatives 3b–g. These unusual molecules show the structural complexity of many biologically active natural products and are endowed with the chemical diversity that is required in drug discovery. The compounds 3b,e were reduced by hydrogen in the presence of Palladium on activated charcoal to give the dihydro derivatives 5b,e. Compounds 3b–f and 5b,e were selected by the NCI to evaluate their in vitro antiproliferative activity against 60 human cell lines derived from nine clinically isolated cancer types (leukaemia, lu…

New Topsentin analogs as inhibitors of biofilm formation

Branched High Molecular Weight Glycopolypeptide With Broad-Spectrum Antimicrobial Activity for the Treatment of Biofilm Related Infections.

There are few therapeutic options to simultaneously tackle Staphylococcus aureus and Pseudomonas aeruginosa, two of the most relevant nosocomial and antibiotic-resistant pathogens responsible for implant, catheters and wound severe infections. The design and synthesis of polymers with inherent antimicrobial activity have gained increasing attention as a safe strategy to treat multi-drug-resistant microbes. Here, we tested the activity of a new polymeric derivative with glycopolypeptide architecture (PAA-VC) bearing l-arginine, vancomycin, and colistin as side chains acting against multiple targets, which give rise to a broad spectrum antimicrobial activity favorably combining specific and n…

Nano into Micro Formulations of Tobramycin for the Treatment of Pseudomonas aeruginosa Infections in Cystic Fibrosis.

Here, nano into micro formulations (NiMs) of tobramycin for the treatment of Pseudomonas aeruginosa airway infections in cystic fibrosis (CF) are described. NiMs were produced by spray drying a solution containing polymers or sugars and a nanometric polyanion–tobramcyin complex (PTC), able to achieve a prolonged antibiotic release. NiMs properties were compared to TOBIPodhaler(Novartis), the only one commercially available dry powder inhalatory formulation based on porous microparticles. Produced NiMs showed adequate characteristics for pulmonary administration, as spherical shape, micrometric size, and high cytocompatibility toward human bronchial epithelial cells. Contrarily to TOBIPodhal…

The immune mediators in echinoderms as souce of novel AMPs against microbial biofilms

New Anti-Adhesion Agents In The Development of Antivirulence Drugs

Gram-positive bacteria are a significant cause of nosocomial and community-acquired infections associated with diseases of high morbidity and mortality. Moreover, antibiotic resistance of important Gram-positive pathogens, such as Staphylococcus aureus, Streptococcus pneumoniae and Enterococcus faecalis is one of the major worldwide health problems. Over the last decade, many studies have focused on agents that target the virulence of important pathogens without killing or inhibiting their growth therefore imposing limited selective pressure to promote the development and spread of resistance mechanisms [1]enterococci and streptococci, sortase A plays a critical role in Gram-positive bacter…

1,2,4-Oxadiazole topsentin analogs as staphylococcal biofilm inhibitors targeting the bacterial transpeptidase sortase A

The inhibition or prevention of biofilm formation represents an emerging strategy in the war against antibiotic resistance, interfering with key players in bacterial virulence. This approach includes the inhibition of the catalytic activity of transpeptidase sortase A (Srt A), a membrane enzyme responsible for covalently attaching a wide variety of adhesive matrix molecules to the peptidoglycan cell wall in Gram-positive strains. A new series of seventeen 1,2,4-oxadiazole derivatives was efficiently synthesized and screened as potential new anti-virulence agents. The ability of inhibiting biofilm formation was evaluated against both Gram-positive and Gram-negative pathogens. Remarkably, all…

Paracentrin 1, a synthetic antimicrobial peptide from the sea-urchin Paracentrotus lividus, interferes with staphylococcal and Pseudomonas aeruginosa biofilm formation

The rise of antibiotic-resistance as well as the reduction of investments by pharmaceutical companies in the development of new antibiotics have stimulated the investigation for alternative strategies to conventional antibiotics. Many antimicrobial peptides show a high specificity for prokaryotes and a low toxicity for eukaryotic cells and, due to their mode of action the development of resistance is considered unlikely. We recently characterized an antimicrobial peptide that was called Paracentrin 1 from the 5-kDa peptide fraction from the coelomocyte cytosol of the Paracentrotus lividus. In this study, the chemically synthesized Paracentrin 1, was tested for its antimicrobial and antibiof…

Synthesis and biological evaluation of new 2-{[(2E)-3-phenylprop-2-enoyl]amino}benzamides

Biofilm capability of staphylococcus strains isolated from food and the anti-biofilm activity of a chemically synthesized pyrrolomycin

&#x0D; This electronic document is a “live” template. The various components of your paper [title, text, tables, figures and references] are already defined on the style sheet, as illustrated by the portions given in this document.&#x0D;

GENETICS AND BIOFILM ANALYSIS ON STRAINS OF E.COLI ISOLATED FROM ANIMALS WITH DIARRHOEIC PROBLEMS

AMPs and biotechnology application for new generation of medical devices

SYNTHETIC AND BIOLOGICAL EVALUATION OF SOME NEW 2-CINNAMAMIDOBENZAMIDES AS POTENTIAL ANTAGONIST OF THE HDM2-P53 PROTEIN-PROTEIN INTERACTIONS

Discovery of a New Class of Sortase A Transpeptidase Inhibitors to Tackle Gram-positive Pathogens: 2-Phenylhydrazonoalkanoic Acid Derivatives

There is an urgent need of anti-virulence agents effective in the prevention or eradication of biofilms that are intrinsically resistant to conventional antibiotics. If we consider that the first step of staphylococcal pathogenesis and of biofilm formation is the bacterial adhesion, promoted by the surface exposed proteins at the cell wall, we believe that new anti-virulence agents could be developed by using as a target the Sortase A (SrtA), the enzyme responsible of linking surface exposed proteins to peptidoglycan. Therefore, SrtA inhibitors could act as anti-adhesion agents useful to prevent Gram positive virulence mechanisms as well as a virulence mechanism based on biofilm formation. …

Identification of New Antimicrobial Peptides from Mediterranean Medical Plant Charybdis pancration (Steinh.) Speta

The present work was designed to identify and characterize novel antimicrobial peptides (AMPs) from Charybdis pancration (Steinh.) Speta, previously named Urginea maritima, is a Mediterranean plant, well-known for its biological properties in traditional medicine. Polypeptide-enriched extracts from different parts of the plant (roots, leaves and bulb), never studied before, were tested against two relevant pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. With the aim of identifying novel natural AMPs, peptide fraction displaying antimicrobial activity (the bulb) that showed minimum inhibitory concentration (MICs) equal to 30 &micro

Pyrrolomycins as potential anti-staphylococcal biofilms agents

With the goal of discovering new anti-infective agents active against microbial biofilms, this investigation focused on some natural pyrrolomycins, a family of halogenated pyrrole antibiotics. In this study the anti-staphylococcal biofilm activity of pyrrolomycins C, D, F1, F2a, F2b, F3 and of the synthesized related compounds I, II, III were investigated. The susceptibility of six staphylococcal biofilms was determined by methyltiazotetrazolium staining. Most of the compounds were active at concentrations of 1.5 microg ml(-1) with significant inhibition percentages. A few of the compounds were active at the lowest screening concentration of 0.045 microg ml(-1). The population log reduction…

Molecular characterization of biofilm-forming S.aureus field isolates and their treatment

Pyrazolo[3,4-d]pyrimidine derivatives as COX-2 selective inhibitors: synthesis and molecular modelling studies.

The pyrazolo[3,4-d]pyrimidine system shows a multitude of interesting pharmacological properties. Owing to the potential anti-inflammatory activity of 5-benzamido-pyrazolo[3,4-d]pyrimidin- 4-one derivatives and considering the easy synthesis of this class of compounds, a set of new 5- benzamido-1H-pyrazolo[3,4-d]pyrimidin-4-ones has been prepared in 42-80% yields by reacting 5- aminopyrazole-4(N-benzoyl)carbohydrazide derivatives and the opportune triethylorthoesters. Compounds 8a, b, 10a–d, and 11a, b revealed a superior inhibitory profile against COX-2, when compared to that of reference standards NS398 and indomethacin. Molecular modelling studies confirmed the obtained biological result…

A synthetic derivative of antimicrobial peptide holothuroidin 2 from mediterranean sea cucumber (Holothuria tubulosa) in the control of Listeria monocytogenes

Due to the limited number of available antibiotics, antimicrobial peptides (AMPs) are considered antimicrobial candidates to fight difficult-to-treat infections such as those associated with biofilms. Marine environments are precious sources of AMPs, as shown by the recent discovery of antibiofilm properties of Holothuroidin 2 (H2), an AMP produced by the Mediterranean sea cucumber Holothuria tubulosa. In this study, we considered the properties of a new H2 derivative, named H2d, and we tested it against seven strains of the dangerous foodborne pathogen Listeria monocytogenes. This peptide was more active than H2 in inhibiting the growth of planktonic L. monocytogenes and was able to interf…

2,6-Disubstituted imidazo[2,1-b][1,3,4]thiadiazole derivatives as potent staphylococcal biofilm inhibitors.

Abstract A class of 36 new 2-(6-phenylimidazo[2,-1-b][1,3,4]thiadiazol-2-yl)-1H-indoles was efficiently synthesized and evaluated for their anti-biofilm properties against the Gram-positive bacterial reference strains Staphylococcus aureus ATCC 25923, S. aureus ATCC 6538 and Staphylococcus epidermidis ATCC 12228, and the Gram-negative strains Pseudomonas aeruginosa ATCC 15442 and Escherichia coli ATCC 25922. Many of these new compounds, were able to inhibit biofilm formation of the tested staphylococcal strains showing BIC50 lower than 10 μg/ml. In particular, derivatives 9c and 9h showed remarkable anti-biofilm activity against S. aureus ATCC 25923 with BIC50 values of 0.5 and 0.8 μg/ml, r…

Biogenic iron-silver nanoparticles inhibit bacterial biofilm formation due to Ag+ release as determined by a novel phycoerythrin-based assay

Silver nanoparticles (Ag-NPs) can be considered as a cost-effective alternative to antibiotics. In the presence of Fe(III)-citrate and Ag+, Klebsiella oxytoca DSM 29614 produces biogenic Ag-NPs embedded in its peculiar exopolysaccharide (EPS). K. oxytoca DSM 29614 was cultivated in a defined growth medium–containing citrate (as sole carbon source) and supplemented with Ag+ and either low or high Fe(III) concentration. As inferred from elemental analysis, transmission and scanning electron microscopy, Fourier transform infrared spectrometry and dynamic light scattering, Ag-EPS NPs were produced in both conditions and contained also Fe. The production yield of high-Fe/Ag-EPS NPs was 12 times …

Composizione e attività biologica di “idrolati” di agrumi

Gli idrolati, o acque aromatiche, sono prodotti naturali ricavati dalla distillazione di piante o parti di piante fresche che conservano intatte le loro proprietà e possono essere utilizzati a diverso scopo1. Essi sono comunemente considerati un sottoprodotto degli oli essenziali, ma in realtà, data la diversa composizione e la conseguente maggiore delicatezza, hanno un loro apprezzabile utilizzo, legato comunque al mantenimento delle proprietà delle piante da cui derivano. Nell’industria agrumaria gli idrolati sono il risultato della produzione degli oli essenziali attraverso spremitura a freddo delle bucce degli agrumi e sono considerati un rifiuto da smaltire. Lo studio della composizion…

Antibacterial Activity of Desert Truffles from Saudi Arabia Against Staphylococcus aureus and Pseudomonas aeruginosa

Abstract Medicinal mushrooms represent an unlimited source of polysaccharides with nutritional, antitumoral, antibacterial, and immune-stimulating properties. Traditional studies of epigeous higher Basidiomycetes have recently been joined by studies of hypogeous fungi and, in particular, of so-called desert truffles. With the aim to obtain novel agents against bacteria of clinical importance, we focused on the edible desert truffle mushrooms Tirmania pinoyi, Terfezia claveryi, and Picoa juniperi as sources of new antimicrobial agents. In particular, we investigated the in vitro antibacterial activity of acid-soluble protein extracts (aqueous extracts) of these 3 species against the Gram-pos…

Antibiofilm activity of a novel pyrrolomycin against staphylococcal biofilms of veterinary interest

Antimicrobial and Antibiofilm Activity of a Recombinant Fragment of β-Thymosin of Sea Urchin Paracentrotus lividus

With the aim to obtain new antimicrobials against important pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa, we focused on antimicrobial peptides (AMPs) from Echinoderms. An example of such peptides is Paracentrin 1 (SP1), a chemically synthesised peptide fragment of a sea urchin thymosin. In the present paper, we report on the biological activity of a Paracentrin 1 derivative obtained by recombination. The recombinant paracentrin RP1, in comparison to the synthetic SP1, is 22 amino acids longer and it was considerably more active against the planktonic forms of S. aureus ATCC 25923 and P. aeruginosa ATCC 15442 at concentrations of 50 &micro

Immune mediators of sea-cucumber Holothuria tubulosa (Echinodermata) as source of novel antimicrobial and anti-staphylococcal biofilm agents

The present study aims to investigate coelomocytes, immune mediators cells in the echinoderm Holothuria tubulosa, as an unusual source of antimicrobial and antibiofilm agents. The activity of the 5kDa peptide fraction of the cytosol from H. tubulosa coelomocytes (5-HCC) was tested against a reference group of Gram-negative and Gram-positive human pathogens. Minimal inhibitory concentrations (MICs) ranging from 125 to 500 mg/ml were determined against tested strains. The observed biological activity of 5-HCC could be due to two novel peptides, identified by capillary RP-HPLC/nESI-MS/MS, which present the common chemical-physical characteristics of antimicrobial peptides. Such peptides were c…

Control of Growth and Persistence of Listeria monocytogenes and β-Lactam-Resistant Escherichia coli by Thymol in Food Processing Settings

The main objective of this study was to evaluate the efficacy of thymol in controlling environmental contamination in food processing facilities. The effect of thymol was tested as an agent to prevent planktonic and bacterial biofilm growth of twenty-five Listeria monocytogenes isolates from a variety of foods and five Escherichia coli isolates from a farm. The E. coli isolates were positive for extended spectrum &beta

Pyrrolomycins as antimicrobial agents. Microwave-assisted organic synthesis and insights into their antimicrobial mechanism of action

Abstract New compounds able to counteract staphylococcal biofilm formation are needed. In this study we investigate the mechanism of action of pyrrolomycins, whose potential as antimicrobial agents has been demonstrated. We performed a new efficient and easy method to use microwave organic synthesis suitable for obtaining pyrrolomycins in good yields and in suitable amount for their in vitro in-depth investigation. We evaluate the inhibitory activity towards Sortase A (SrtA), a transpeptidase responsible for covalent anchoring in Gram-positive peptidoglycan of many surface proteins involved in adhesion and in biofilm formation. All compounds show a good inhibitory activity toward SrtA, havi…

A POLYCARBOXYLIC/AMINO FUNCTIONALIZED HYALURONIC ACID DERIVATIVE FOR THE PRODUCTION OF pH SENSIBLE HYDROGELS IN THE PREVENTION OF BACTERIAL ADHESION ON BIOMEDICAL SURFACES

A graft copolymer derivative of hyaluronic acid bearing pendant amino and short polymethacrylate portions (HA-EDA-BMP-MANa) has been employed for the production of a pH sensible vancomycin releasing hydrogel and studied in vitro to test its potential anti adhesive property against Staphylococcus aureus colonization. The copolymer obtained through atom transfer radical polymerization bears chargeable (carboxyl and amino groups) portions and it could be formulated as a hydrogel at a concentration of 10% w/v. The HA-EDA-BMP-MANa hydrogels, produced at three different pH values (5, 6 and 7, respectively), were formulated with or without the addition of vancomycin (2% w/v). The vancomycin releas…

4-Diazopyrazole Derivatives as Potential New Antibiofilm Agents

&lt;i&gt;Background:&lt;/i&gt; The recognition that chronic infections and infections associated with medical devices are biofilm related has been the impulse for investigating the antibiofilm properties of some diazopyrazoles biologically active as antimicrobials. &lt;i&gt;Methods:&lt;/i&gt; The susceptibility of staphylococcal biofilms was determined at concentrations ranging from 25 to 1.5 µg/ml using crystal violet and methylthiazotetrazolium (MTT) staining. In the case of &lt;i&gt;Candida albicans,&lt;/i&gt; we first assessed the anti-germ tube formation effect of 4-NO&lt;sub&gt;2&lt;/sub&gt; (compound 1c) and then we evaluated its antibiofilm activity at concentrations ranging from 10…

2-Cinnamamido, 2-(3-phenylpropiolamido), and 2-(3-phenylpropanamido)benzamides: synthesis, antiproliferative activity, and mechanism of action

Abstract Several new benzamides 4a–q were synthesized by stirring in pyridine the acid chlorides 3a–q with the appropriate anthranilamide derivatives 2a–g. Some of the synthesized compounds were evaluated for their in vitro antiproliferative activity against a panel of 5 human cell lines (K562 human chronic myelogenous leukemia cells, MCF-7 breast cancer cells, HTC-116 and HT26 colon cancer cells and NCI H460 non-small cell lung cancer cells).

A peptide from human β thymosin as a platform for the development of new anti-biofilm agents for Staphylococcus spp. and Pseudomonas aeruginosa

Conventional antibiotics might fail in the treatment of biofilm-associated infections causing infection recurrence and chronicity. The search for antimicrobial peptides has been performed with the aim to discover novel anti-infective agents active on pathogens in both planktonic and biofilm associated forms. The fragment 9-19 of human thymosin β4 was studied through 1 μs MD simulation. Two main conformations of the peptide were detected, both constituted by a central hydrophobic core and by the presence of peripheral charged residues suggesting a possible mechanism of interaction with two models of biological membranes, related to eukaryotic or bacterial membrane respectively. In addition, …

A new class of phenylhydrazinylidene derivatives as inhibitors of Staphylococcus aureus biofilm formation

In the struggle against the emergence of the antibiotic resistance, new molecules targeting biofilm formation could be useful as adjuvant of conventional antibiotics. This study focused on a new class of 2-phenylhydrazinylidene derivatives as antivirulence agents. The compound 12e showed interesting activities against biofilm formation of all tested Staphylococcus aureus strains with IC50 ranging from 1.7 to 43 µM; compounds 12f and 13a resulted strong inhibitors of S. aureus ATCC 6538 and ATCC 29213 biofilm formation with IC50 of 0.9 and 0.8 µM, respectively. A preliminary study on the mechanism of action was carried on evaluating the inhibition of sortase A transpeptidase. Compound 12e re…

Complementation of the hisBpx mutation in Streptomyces coelicolor A3(2)”.

The Histidinol Phosphate Phosphatase Involved in Histidine Biosynthetic Pathway Is Encoded by SCO5208 (hisN) in Streptomyces coelicolor A3(2)

Through the screening of a Streptomyces coelicolor genomic library, carried out in a histidinol phosphate phosphatase (HolPase) deficient strain, SCO5208 was identified as the last unknown gene involved in histidine biosynthesis. SCO5208 is a phosphatase, and it can restore the growth in minimal medium in this HolPase deficient strain when cloned in a high or low copy number vector. Moreover, it shares sequence homology with other HolPases recently identified in Actinobacteria. During this work a second phosphatase, SCO2771, sharing no homologies with SCO5208 and all so far described phosphatases was identified. It can complement HolPase activity mutation only at high copy number. Sequence …

Origanum vulgare subsp. hirtum Essential Oil Prevented Biofilm formation and showed antibacterial activity against planktonic and sessile bacterial cells

Essential oils from six different populations of Origanum vulgare subsp. hirtum were compared for their antibiofilm properties. The six essential oils (A to F) were characterized by a combination of gas chromatography with flame ionization detector and gas chromatography with mass spectrometer detector analyses. All oils showed weak activity against the planktonic form of a group of Staphylococcus aureus strains and against a Pseudomonas aeruginosa ATCC 15442 reference strain. The ability to inhibit biofilm formation was investigated at sub-MIC levels of 200, 100, and 50 m g/ml by staining sessile cells with safranin. Sample E showed the highest average effectiveness against all tested stra…

Pyrazolo&amp;lsqb;3,4&amp;hyphen;d&amp;rsqb;pyrimidine Derivatives as COX&amp;hyphen;2 Selective Inhibitors: Synthesis and Molecular Modelling Studies

The pyrazolo[3,4-d]pyrimidine system shows a multitude of interesting pharmacological properties. Owing to the potential anti-inflammatory activity of 5-benzamido-pyrazolo[3,4-d]pyrimidin-4-one derivatives and considering the easy synthesis of this class of compounds, a set of new 5-benzamido-1H-pyrazolo[3,4-d]pyrimidin-4-ones has been prepared in 42-80% yields by reacting 5-aminopyrazole-4(N-benzoyl)carbohydrazide derivatives and the opportune triethylorthoesters. Compounds 8a, b, 10a-d, and 11a, b revealed a superior inhibitory profile against COX-2, when compared to that of reference standards NS398 and indomethacin. Molecular modelling studies confirmed the obtained biological results.

Identification of SCP2165, a new SCP2-derived plasmid of Streptomyces coelicolor A3(2).

Aims:  Characterization of SCP2165, a plasmid identified in the Gram-positive bacterium Streptomyces coelicolor A3(2). Methods and Results:  Pulsed-field gel electrophoresis (PFGE) of mycelia of a S. coelicolor strain embedded in low melting agarose revealed the presence of a plasmid. Restriction enzyme mapping and sequence analysis of a 2·1 kb fragment revealed that this plasmid could be SCP2. SCP2 and its spontaneous derivative SCP2* are self-transmissible plasmids and have chromosome mobilizing ability (c.m.a.). SCP2* has a c. 1000-fold increased c.m.a. compared with SCP2. Interestingly the plasmid, named SCP2165, shows a c.m.a. from 5 × 10−2 to 1 × 10−1 which is 50–100-fold higher than …

New Thiazole Nortopsentin Analogues Inhibit Bacterial Biofilm Formation.

New thiazole nortopsentin analogues were conveniently synthesized and evaluated for their activity as inhibitors of biofilm formation of relevant Gram-positive and Gram-negative pathogens. All compounds were able to interfere with the first step of biofilm formation in a dose-dependent manner, showing a selectivity against the staphylococcal strains. The most active derivatives elicited IC50 values against Staphylococcus aureus ATCC 25923, ranging from 0.40&ndash