scholarly journals Cyanobacteria and Eukaryotic Microalgae as Emerging Sources of Antibacterial Peptides

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5804
Author(s):  
Verónica Rojas ◽  
Luis Rivas ◽  
Constanza Cárdenas ◽  
Fanny Guzmán
Keyword(s):  
Cyclic Peptides ◽  
Extreme Environments ◽  
Mechanisms Of Action ◽  
Microbial Pathogens ◽  
Antibacterial Peptides ◽  
Tetraselmis Suecica ◽  
Antibacterial Compounds ◽  
Gram Positive Bacteria ◽  
Unicellular Organisms ◽  
Chlorella Species

Cyanobacteria and microalgae are oxygen-producing photosynthetic unicellular organisms encompassing a great diversity of species, which are able to grow under all types of extreme environments and exposed to a wide variety of predators and microbial pathogens. The antibacterial compounds described for these organisms include alkaloids, fatty acids, indoles, macrolides, peptides, phenols, pigments and terpenes, among others. This review presents an overview of antibacterial peptides isolated from cyanobacteria and microalgae, as well as their synergism and mechanisms of action described so far. Antibacterial cyanopeptides belong to different orders, but mainly from Oscillatoriales and Nostocales. Cyanopeptides have different structures but are mainly cyclic peptides. This vast peptide repertoire includes ribosomal and abundant non-ribosomal peptides, evaluated by standard conventional methodologies against pathogenic Gram-negative and Gram-positive bacteria. The antibacterial activity described for microalgal peptides is considerably scarcer, and limited to protein hydrolysates from two Chlorella species, and few peptides from Tetraselmis suecica. Despite the promising applications of antibacterial peptides and the importance of searching for new natural sources of antibiotics, limitations still persist for their pharmaceutical applications.

scholarly journals Leveraging phytochemicals: the plant phylogeny predicts sources of novel antibacterial compounds

2019 ◽  
Vol 5 (7) ◽  
pp. FSO407 ◽  
Author(s):  
Malini A Prasad ◽  
Christine P Zolnik ◽  
Jeanmaire Molina
Keyword(s):  
Cell Wall ◽  
Antibacterial Activity ◽  
Mechanisms Of Action ◽  
Antibacterial Drug ◽  
Antibacterial Compounds ◽  
Plant Phylogeny ◽  
Biofilm Production ◽  
Potential Sources ◽  
Plant Families ◽  
High Representation

Aim: The goal of this study was to use phylogenetic evidence to determine plant families with high representation of antibacterial activity and identify potential sources to focus on for antibacterial drug discovery. Materials & methods: We reconstructed the molecular phylogeny of plant taxa with antibacterial activity and mapped antibacterial mechanisms of action on the phylogeny. Results: The phylogeny highlighted seven plant families (Combretaceae, Cupressaceae, Fabaceae, Lamiaceae, Lauraceae, Myrtaceae and Zingiberaceae) with disproportionately represented antibacterial activity. Phytochemicals produced were primarily involved in the disruption of the bacterial cell wall/membrane and inhibition of quorum sensing/biofilm production. Conclusion: The study provides phylogenetic evidence of seven plant families that should be examined as promising leads for novel antibacterial development.

Gausemycins A,B – Cyclic Lipoglycopeptides from Streptomyces Sp.

2020 ◽  
Author(s):  
Anton Tyurin ◽  
Vera Alferova ◽  
Alexander Paramonov ◽  
Maxim Shuvalov ◽  
Gulnara Kudryakova ◽  
...  
Keyword(s):  
Cyclic Peptides ◽  
Pore Formation ◽  
Structural Features ◽  
Side Chain ◽  
Peptide Antibiotic ◽  
Streptomyces Sp ◽  
Gram Positive Bacteria ◽  
Low Concentrations ◽  
Phenylbutyric Acid ◽  
Peptide Core

We report a novel family of natural lipoglycopeptides produced by Streptomyces sp. INA-Ac-5812. Two major components of the mixture, named gausemycins A and B, were isolated, and their structures were elucidated. The compounds are cyclic peptides with a unique peptide core and several remarkable structural features, including unusual positions of D-amino acids, lack of the Ca2+ -binding Asp-X-Asp-Gly (DXDG) motif, tyrosine glycosylation with arabinose, presence of 2-amino-4-hydroxy-4- phenylbutyric acid (Ahpb) and chlorinated kynurenine (ClKyn), N-acylation of the ornithine side chain. These major components of the peptide antibiotic family have pronounced activity against Gram-positive bacteria. The mechanism of action of gausemycins was explored by a number of methods, showing significant differences compared to glycopeptides and related lipopeptides. For example, gausemycins exhibit no Ca2+ -dependence of antimicrobial activity and induce no pore formation at low concentrations. Moreover, there is no detectable accumulation of cell wall biosynthesis precursors under treatment with gausemycins.

scholarly journals Antimicrobial Photodynamic Activity of Phthalocyanine Derivatives

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Samuel N. Nyamu ◽  
Lucy Ombaka ◽  
Eric Masika ◽  
Margaret Ng’ang’a
Keyword(s):  
Microbial Pathogens ◽  
Quantum Yields ◽  
Promising Alternative ◽  
The Public ◽  
Gram Positive Bacteria ◽  
Photodynamic Activity ◽  
Alternative Approaches ◽  
Therapeutic Properties ◽  
Photochemical Properties ◽  
Bacteria Resistance

Microbial pathogens have increasingly shown multidrug resistance posing a serious threat to the public health. Advances in technology are opening novel avenues for discovery of compounds that will mitigate the ever-increasing drug-resistant microbes. Use of photodynamic photosensitizer is one of the promising alternative approaches since they offer low risk of bacteria resistance as they use generated reactive oxygen species to kill the microbes. Phthalocyanine (Pc) is one such photosensitizer which has already shown promising antimicrobial photodynamic therapeutic properties. Previous studies have shown effectiveness of the Pc against Gram-positive bacteria. However, its effectiveness toward Gram-negative bacteria is limited by the impermeability of the bacteria’s outer membrane which is made up of lipopolysaccharides layer. The effectiveness of this photosensitizer is determined by its photophysical and photochemical properties such as singlet/triplet lifetimes, singlet oxygen quantum yields, and fluorescence quantum yield. Therefore, this review focuses on the recent significance advances on designing Pc that have this improved property by either conjugating with nanoparticles, quantum dots, functional groups in peripheral position, considering effect of cationic charge, and its position on the macrocycle.

scholarly journals New Insights into Antibacterial Compounds: From Synthesis and Discovery to Molecular Mechanisms of Action

Antibiotics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 471
Author(s):  
Jorge H. Leitão
Keyword(s):  
Molecular Mechanisms ◽  
Antimicrobial Activities ◽  
Mechanisms Of Action ◽  
Special Issue ◽  
Exciting Field ◽  
Antibacterial Compounds ◽  
Surveillance Studies ◽  
Wide Range ◽  
Recent Developments ◽  
Global Threat

The worldwide emergence of microbial resistance to available antibiotics presents a global threat to public health and health systems. This special issue aimed to gather papers describing novel antibiotics, originating form chemical synthesis, repurposing of existent drugs, or from natural sources like plant extracts, herbs and spices. A total of 13 papers were published, covering a wide range of topic, including antimicrobial resistance surveillance studies; synthesis of novel molecules with antimicrobial activities; modification or repurposing of already existing molecules, plant-derived active extracts, and molecules; the effects of antimicrobial therapy on microbiota; and the investigation of novel formulations for human and veterinary uses. After decades of antibiotics discovery decline, antibiotics discovery is boosting. Recent developments of post genomics approaches and bioinformatics tools will most certainly turn the tide in the discovery and development of antimicrobials in this exciting field.

scholarly journals Chemical Characterization and Biological Properties of NVC-422, a Novel, StableN-Chlorotaurine Analog

2011 ◽  
Vol 55 (6) ◽  
pp. 2688-2692 ◽  
Author(s):  
Lu Wang ◽  
Barbara Belisle ◽  
Mansour Bassiri ◽  
Ping Xu ◽  
Dmitri Debabov ◽  
...  
Keyword(s):  
Antimicrobial Properties ◽  
Chemical Characterization ◽  
Biological Properties ◽  
Microbial Pathogens ◽  
Antibiotic Resistant ◽  
Content Type ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Microbial Strains

ABSTRACTDuring oxidative burst, neutrophils selectively generate HOCl to destroy invading microbial pathogens. Excess HOCl reacts with taurine, a semi-essential amino acid, resulting in the formation of the longer-lived biogenerated broad-spectrum antimicrobial agent,N-chlorotaurine (NCT). In the presence of an excess of HOCl or under moderately acidic conditions, NCT can be further chlorinated, or it can disproportionate to produceN,N-dichlorotaurine (NNDCT). In the present study, 2,2-dimethyltaurine was used to prepare a more stableN-chlorotaurine, namely,N,N-dichloro-2,2-dimethyltaurine (NVC-422). In addition, we report on the chemical characterization,in vitroantimicrobial properties, and cytotoxicity of this compound. NVC-422 was shown effectively to kill all 17 microbial strains tested, including antibiotic-resistantStaphylococcus aureusandEnterococcus faecium. The minimum bactericidal concentration of NVC-422 against Gram-negative and Gram-positive bacteria ranged from 0.12 to 4 μg/ml. The minimum fungicidal concentrations againstCandida albicansandCandida glabratawere 32 and 16 μg/ml, respectively. NVC-422 has anin vitrocytotoxicity (50% cytotoxicity = 1,440 μg/ml) similar to that of NNDCT. Moreover, our data showed that this agent possesses rapid, pH-dependent antimicrobial activity. At pH 4, NVC-422 completely killed bothEscherichia coliandS. aureuswithin 5 min at a concentration of 32 μg/ml. Finally, the effect of NVC-422 in the treatment of anE. coli-infected granulating wound rat model was evaluated. Treatment of the infected granulating wound with NVC-422 resulted in significant reduction of the bacterial tissue burden and faster wound healing compared to a saline-treated control. These findings suggest that NVC-422 could have potential application as a topical antimicrobial.

scholarly journals Prediction of Mechanisms of Action of Antibacterial Compounds by Gene Expression Profiling

2004 ◽  
Vol 48 (8) ◽  
pp. 2838-2844 ◽  
Author(s):  
Bernd Hutter ◽  
Christoph Schaab ◽  
Sebastian Albrecht ◽  
Matthias Borgmann ◽  
Nina A. Brunner ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Expression Profiles ◽  
Model Organism ◽  
Mechanisms Of Action ◽  
Support Vector ◽  
Transcriptional Responses ◽  
Antibacterial Compounds ◽  
Potential Applications

ABSTRACT We have generated a database of expression profiles carrying the transcriptional responses of the model organism Bacillus subtilis following treatment with 37 well-characterized antibacterial compounds of different classes. The database was used to build a predictor for the assignment of the mechanisms of action (MoAs) of antibacterial compounds by the use of support vector machines. This predictor was able to correctly classify the MoA class for most compounds tested. Furthermore, we provide evidence that the in vivo MoA of hexachlorophene does not match the MoA predicted from in vitro data, a situation frequently faced in drug discovery. A database of this kind may facilitate the prioritization of novel antibacterial entities in drug discovery programs. Potential applications and limitations are discussed.

scholarly journals Anti Bacterial Activity of Fungi TIF-1 as Saponin Producer

2017 ◽  
Vol 2 (2) ◽  
pp. 166
Author(s):  
Willy Tirza Eden ◽  
Ersanghono Kusumo ◽  
Eko Budi Susatyo ◽  
Kasmui Kasmui
Keyword(s):  
Antibacterial Activity ◽  
Ethyl Acetate ◽  
Microbial Pathogens ◽  
Gram Negative Bacteria ◽  
Test Results ◽  
Chromatography Method ◽  
Microbial Resistance ◽  
Gram Positive Bacteria ◽  
Potential Source ◽  
Layer Chromatography

<p style="text-align: justify;">Treatment of microbial resistance is one of humankind's greatest challenges in terms of fight against infectious diseases. One way to overcome microbial resistance is discovery of potent new antimicrobial compounds against variety of microbial pathogens. Land is one potential source of microorganisms. This study aims to screen in order to get a fungal strains isolated from soil exposed to waste the pharmaceutical industry which possess antibacterial activity. Antibacterial activity test conducted on two types of bacteria, namely Staphylococcus aureus as Gram-positive bacteria and Escherichia coli as Gram-negative bacteria. The test results can be known isolates of fungi which has potential as an antibacterial, for then these are fermented for 10 days. Fermented then partitioned by using ethyl acetate. Initial screening showed that the fungi code TIF-1 as the most active fungi. Ethyl acetate soluble fraction was then identified the active compounds using thin layer chromatography method with various reagent spray. Bioautografi test results show that the saponins which play role in the antibacterial activity. ©2016 JNSMR UIN Walisongo. All rights reserved.</p>

Antibacterial activity of casein-derived peptides isolated from rabbit (Oryctolagus cuniculus) milk

2003 ◽  
Vol 70 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Maria Baranyi ◽  
Ursula Thomas ◽  
Antonio Pellegrini
Keyword(s):  
Antibacterial Activity ◽  
Antibacterial Effect ◽  
Antibacterial Properties ◽  
Milk Proteins ◽  
Reversed Phase ◽  
Antibacterial Peptides ◽  
Proteolytic Digestion ◽  
Peptide Fragments ◽  
Gram Positive Bacteria ◽  
Micro Organisms

Acid-precipitated rabbit ‘whole casein’ was digested by trypsin, chymotrypsin, pepsin, and clostripain to screen for possible peptides with antibacterial properties. The peptide fragments were separated by reversed-phase chromatography. The collected fractions were pooled and their antibacterial properties tested against Escherichia coli, Bacillus subtilis and Staphylococcus lentus. Three antibacterial peptide fragments derived from tryptic digestion of rabbit casein were isolated and identified. Their sequences were found as follows: HVEQLLR (residues 50–56 of β-casein), ILPFIQSLFPFAER (residues 64–77 of β-casein), and FHLGHLK (residues 19–25 of αs1-casein). The three peptides were synthesized and found to exert antibacterial effect against Gram positive bacteria only. Proteolytic digestion of rabbit casein by chymotrypsin, pepsin and clostripain yielded several peptide fragments with antibacterial activity. Since antibiotic peptides can be released from casein during the digestion of milk proteins, our results suggest a possible antibacterial function of rabbit caseins. It is conceivable that antibacterial peptides can be generated by endopeptidases of the mammalian gastrointestinal tract possibly providing protection for new-born rabbits against aggression of micro-organisms.

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