Search results for "antimicrobial"

Synthesis and biological evaluation of new indazole derivatives

2010

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.

2015

Marine indole alkaloids comprise a large and steadily growing group of secondary metabolites. Their diverse biological activities make many compounds of this class attractive starting points for pharmaceutical development. Several marine-derived indoles were found to possess cytotoxic, antineoplastic, antibacterial and antimicrobial activities, in addition to the action on human enzymes and receptors. The newly isolated indole alkaloids of marine origin since the last comprehensive review in 2003 are reported, and biological aspects will be discussed.

Synthesis and Antitumor Activity of 3-(2-Phenyl-1,3-thiazol-4-yl)-1H-indoles and 3-(2-Phenyl-1,3-thiazol-4-yl)-1H-7-azaindoles

2011

Given the potent antimicrobial, antiviral, and antitumor activities of many natural products, there is an increasing interest in the synthesis of new molecules based on natural compound scaffolds. Based on a 2,4-bis(3'-indolyl)imidazole skeleton, two new series of phenylthiazolylindoles and phenylthiazolyl-7-azaindoles were obtained by Hantzsch reaction between substituted phenylthioamides and the α-bromoacetyl derivatives. Some azaindole derivatives, tested at the National Cancer Institute against a panel of ∼60 tumor cell lines derived from nine human cancer cell types, showed inhibitory effects against all cell lines investigated at micromolar to nanomolar concentrations. Two of them exh…

The effect of essential oils on norovirus surrogates

2013

Abstract Essential oils (EOs) have long been applied as flavoring agents in foods, and due to their content in antimicrobial compounds, they have potential as natural agents for food preservation. In this study the effect of three EOs, clove, oregano and zataria, was evaluated on the infectivity of norovirus surrogates, i.e. feline calicivirus (FCV) and murine norovirus (MNV). Different concentrations of EOs were individually mixed with each virus at titers of ca. 7–8 log TCID 50 /ml and incubated for 2 h at 4 °C and 37 °C. The infectivity of the recovered viruses after triplicate treatments was evaluated by cell-culture assays. 2% of oregano EO at 37 °C decreased the FCV titers by 3.75 log…

Identification of the Gene Repertoire of the IMD Pathway and Expression of Antimicrobial Peptide Genes in Several Tissues and Hemolymph of the Cockro…

2022

This article belongs to the Special Issue Antimicrobial Peptides and Immunology.

Echinoderm Antimicrobial Peptides to Contrast Human Pathogens

2013

Increased attention has been focused in 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 sea urchin and sea cucumber are antimicrobial peptides (AMP) active against Gram positive, Gram negative and fungi. In this review we described the most recent studies on AMP isolated from echinoderms. The AMP are little peptides <10 kDa with cationic charge and amphipathic structure. Recently, it was demonstrated that in the coelomocyte lysates of Paracentrotus. lividus and Holothuria tubulosa AMP are present with activity against staphylococcal and Pseud…

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

2014

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…

The potential of antimicrobial peptides isolated from freshwater crayfish species in new drug development: A review

2021

Abstract The much-publicised increased resistance of pathogenic bacteria to conventional antibiotics has focused research effort on the characterization of new antimicrobial drugs. In this context, antimicrobial peptides (AMPs) extracted from animals are considered a promising alternative to conventional antibiotics. In recent years, freshwater crayfish species have emerged as an important source of bioactive compounds. In fact, these invertebrates rely on an innate immune system based on cellular responses and on the production of important effectors in the haemolymph, such as AMPs, which are produced and stored in granules in haemocytes and released after stimulation. These effectors are …

Localization of antimicrobial peptides in the tunic of Ciona intestinalis (Ascidiacea, Tunicata) and their involvement in local inflammatory-like rea…

2011

AbstractTunicates comprising a wide variety of different species synthesize antimicrobial peptides as important effector molecules of the innate immune system. Recently, two putative gene families coding for antimicrobial peptides were identified in the expressed sequence tag database of the tunicate Ciona intestinalis. Two synthetic peptides representing the cationic core region of one member of each of the families displayed potent antibacterial and antifungal activities. Moreover, the natural peptides were demonstrated to be synthesized and stored in distinct hemocyte types. Here, we investigated the presence of these natural peptides, namely Ci-MAM-A and Ci-PAP-A, in the tunic of C. int…

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

2013

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…