scholarly journals Simple Approaches for the Synthesis of AgNPs in Solution and Solid Phase Using Modified Methoxypolyethylene Glycol and Evaluation of Their Antimicrobial Activity

2020 ◽  
Vol Volume 15 ◽  
pp. 2353-2362
Author(s):  
Ayman El-Faham ◽  
Hessa H Al-Rasheed ◽  
Essam N Sholkamy ◽  
Sameh M Osman ◽  
Zeid A ALOthman
Keyword(s):  
Antimicrobial Activity ◽  
Solid Phase ◽  
Methoxypolyethylene Glycol

scholarly journals Identification and Antimicrobial Activity of Medium-Sized and Short Peptides from Yellowfin Tuna (Thunnus albacares) Simulated Gastrointestinal Digestion

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1185
Author(s):  
Andrea Cerrato ◽  
Anna Laura Capriotti ◽  
Federico Capuano ◽  
Chiara Cavaliere ◽  
Angela Michela Immacolata Montone ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Solid Phase ◽  
Model Organism ◽  
Graphitized Carbon Black ◽  
Yellowfin Tuna ◽  
Short Peptides ◽  
Gastrointestinal Digestion ◽  
Exact Mass ◽  
Short Peptide ◽  
Simulated Gastrointestinal Digestion

Due to the rapidly increasing resistance to conventional antibiotics, antimicrobial peptides are emerging as promising novel drug candidates. In this study, peptide fragments were obtained from yellowfin tuna muscle by simulated gastrointestinal digestion, and their antimicrobial activity towards Gram-positive and Gram-negative bacteria was investigated. In particular, the antimicrobial activity of both medium- and short-sized peptides was investigated by using two dedicated approaches. Medium-sized peptides were purified by solid phase extraction on C18, while short peptides were purified thanks to a graphitized carbon black sorbent. For medium-sized peptide characterization, a peptidomic strategy based on shotgun proteomics analysis was employed, and identification was achieved by matching protein sequence database by homology, as yellowfin tuna is a non-model organism, leading to the identification of 403 peptides. As for short peptide sequences, an untargeted suspect screening approach was carried out by means of an inclusion list presenting the exact mass to charge ratios (m/z) values for all di-, tri- and tetrapeptides. In total, 572 short sequences were identified thanks to a customized workflow dedicated to short peptide analysis implemented on Compound Discoverer software.

scholarly journals Increases in Hydrophilicity and Charge on the Polar Face of Alyteserin 1c Helix Change its Selectivity towards Gram-Positive Bacteria

Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 238 ◽  
Author(s):  
Yamil Liscano ◽  
Constain H. Salamanca ◽  
Lina Vargas ◽  
Stefania Cantor ◽  
Valentina Laverde-Rojas ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Solid Phase ◽  
Structural Characteristics ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Mutant Derivative ◽  
Conventional Antibiotics ◽  
Carboxy Terminal

Recently, resistance of pathogens towards conventional antibiotics has increased, representing a threat to public health globally. As part of the fight against this, studies on alternative antibiotics such as antimicrobial peptides have been performed, and it has been shown that their sequence and structure are closely related to their antimicrobial activity. Against this background, we here evaluated the antibacterial activity of two peptides developed by solid-phase synthesis, Alyteserin 1c (WT) and its mutant derivative (ΔM), which shows increased net charge and reduced hydrophobicity. These structural characteristics were modified as a result of amino acid substitutions on the polar face of the WT helix. The minimum inhibitory concentration (MIC) of both peptides was obtained in Gram-positive and Gram-negative bacteria. The results showed that the rational substitutions of the amino acids increased the activity in Gram-positive bacteria, especially against Staphylococcus aureus, for which the MIC was one-third of that for the WT analog. In contrast to the case for Gram-positive bacteria, these substitutions decreased activity against Gram-negative bacteria, especially in Escherichia coli, for which the MIC was eight-fold higher than that exhibited by the WT peptide. To understand this, models of the peptide behavior upon interacting with membranes of E. coli and S. aureus created using molecular dynamics were studied and it was determined that the helical stability of the peptide is indispensable for antimicrobial activity. The hydrogen bonds between the His20 of the peptides and the phospholipids of the membranes should modulate the selectivity associated with structural stability at the carboxy-terminal region of the peptides.

scholarly journals Effects of Dimerization on the Structure and Biological Activity of Antimicrobial Peptide Ctx-Ha

2012 ◽  
Vol 56 (6) ◽  
pp. 3004-3010 ◽  
Author(s):  
E. N. Lorenzón ◽  
G. F. Cespedes ◽  
E. F. Vicente ◽  
L. G. Nogueira ◽  
T. M. Bauab ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Biological Activity ◽  
Antimicrobial Peptide ◽  
Hemolytic Activity ◽  
Pore Diameter ◽  
Solid Phase ◽  
Biological Activities ◽  
Solid Phase Peptide Synthesis ◽  
Activity Assay ◽  
Growth Of Bacteria

ABSTRACTIt is well known that cationic antimicrobial peptides (cAMPs) are potential microbicidal agents for the increasing problem of antimicrobial resistance. However, the physicochemical properties of each peptide need to be optimized for clinical use. To evaluate the effects of dimerization on the structure and biological activity of the antimicrobial peptide Ctx-Ha, we have synthesized the monomeric and three dimeric (Lys-branched) forms of the Ctx-Ha peptide by solid-phase peptide synthesis using a combination of 9-fluorenylmethyloxycarbonyl (Fmoc) andt-butoxycarbonyl (Boc) chemical approaches. The antimicrobial activity assay showed that dimerization decreases the ability of the peptide to inhibit growth of bacteria or fungi; however, the dimeric analogs displayed a higher level of bactericidal activity. In addition, a dramatic increase (50 times) in hemolytic activity was achieved with these analogs. Permeabilization studies showed that the rate of carboxyfluorescein release was higher for the dimeric peptides than for the monomeric peptide, especially in vesicles that contained sphingomyelin. Despite different biological activities, the secondary structure and pore diameter were not significantly altered by dimerization. In contrast to the case for other dimeric cAMPs, we have shown that dimerization selectively decreases the antimicrobial activity of this peptide and increases the hemolytic activity. The results also show that the interaction between dimeric peptides and the cell wall could be responsible for the decrease of the antimicrobial activity of these peptides.

scholarly journals Bioguided Fractionation ShowsCassia alataExtract to InhibitStaphylococcus epidermidisandPseudomonas aeruginosaGrowth and Biofilm Formation

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Samuel Takashi Saito ◽  
Danielle da Silva Trentin ◽  
Alexandre José Macedo ◽  
Cristina Pungartnik ◽  
Grace Gosmann ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Biofilm Formation ◽  
Leaf Extract ◽  
High Resolution Mass Spectrometry ◽  
Solid Phase ◽  
Folk Medicine ◽  
Bacterial Biofilm ◽  
Aqueous Leaf Extract ◽  
Overlay Technique ◽  
Agar Overlay Technique

Plant extracts have a long history to be used in folk medicine.Cassia alataextracts are known to exert antibacterial activity but details on compounds and mechanism of action remain poorly explored. We purified and concentrated the aqueous leaf extract ofC. alataby reverse phase-solid phase extraction and screened the resulting CaRP extract for antimicrobial activity. CaRP extract exhibited antimicrobial activity forPseudomonas aeruginosa,Staphylococcus epidermidis,S. aureus, andBacillus subtilis. CaRP also inhibited biofilm formation ofS. epidermidisandP. aeruginosa. Several bacterial growth-inhibiting compounds were detected when CaRP extract was fractionated by TLC chromatography coupled to bioautography agar overlay technique. HPLC chromatography of CaRP extract yielded 20 subfractions that were tested by bioautography for antimicrobial activity againstS. aureusandS. epidermidis. Five bioactive fractions were detected and chemically characterized, using high-resolution mass spectrometry (qTOF-MS/MS). Six compounds from four fractions could be characterized as kaempferol, kaempferol-O-diglucoside, kaempferol-O-glucoside, quercetin-O-glucoside, rhein, and danthron. In theSalmonella/microsome assay CaRP showed weak mutagenicity (MI<3) only in strain TA98, pointing to a frameshift mutation activity. These results indicate thatC. alataleaf extract contains a minimum of 7 compounds with antimicrobial activity and that these together or as single substance are active in preventing formation of bacterial biofilm, indicating potential for therapeutic applications.

Improved solid-phase synthesis of α,α-dialkylated amino acid-rich peptides with antimicrobial activity*

2008 ◽  
Vol 66 (6) ◽  
pp. 333-347 ◽  
Author(s):  
S.R. Haynes ◽  
S.D. Hagins ◽  
M.M. Juban ◽  
P.H. Elzer ◽  
R.P. Hammer
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Phase Synthesis

Solid-Phase Synthesis of 5-Arylhistidine-Containing Peptides with Antimicrobial Activity Through a Microwave-Assisted Suzuki-Miyaura Cross-Coupling

2012 ◽  
Vol 2012 (23) ◽  
pp. 4321-4332 ◽  
Author(s):  
Iteng Ng-Choi ◽  
Marta Soler ◽  
Vanessa Cerezo ◽  
Esther Badosa ◽  
Emilio Montesinos ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Cross Coupling ◽  
Phase Synthesis ◽  
Microwave Assisted

scholarly journals Kainari, a Unique Greek Traditional Herbal Tea, from the Island of Lesvos: Chemical Analysis and Antioxidant and Antimicrobial Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Evangelia Bampali ◽  
Konstantia Graikou ◽  
Nektarios Aligiannis ◽  
Ioanna Chinou
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Analysis ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Solid Phase ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Antimicrobial Properties ◽  
Total Phenolic ◽  
Herbal Tea

The chemical composition, as well as the total phenolic content (TPC) and the potential antioxidant and antimicrobial activity, of three Kainari-herbal tea samples from different areas of Lesvos Island (Greece) was evaluated. The rich aroma of the mixtures was studied through GC-MS, as well as through Headspace Solid-Phase Microextraction (HS-SPME)/GC-MS analyses. Cinnamon, clove, nutmeg, pepper, and ginger were identified as main ingredients, while, throughout the chemical analysis of the volatiles of one selected sample, several secondary metabolites have been isolated and identified on the basis of GC-MS as well as spectral evidence as eugenol, cinnamic aldehyde and myristicin, cinnamyl alcohol, alpha-terpinyl acetate, and β-caryophyllene. Furthermore, two food dyes, azorubine and amaranth, were also isolated and identified from the infusions. The total phenolic content was estimated and the free radical scavenging activity was determined by DPPH and ABTS assays and the antimicrobial activity of the extracts was tested showing a very interesting profile against all the assayed microorganisms. Due to its very pleasant aroma and taste properties as well as to its bioactivities, Kainari-herbal tea could be further proposed as functional beverage.

scholarly journals Towards the production of tikitericin: A novel peptide from Thermogemmatispora strain T81

2021 ◽  
Author(s):  
◽  
Benjamin Baker
Keyword(s):  
Antimicrobial Activity ◽  
Natural Products ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Genome Mining ◽  
New Drugs ◽  
Taupo Volcanic Zone ◽  
Ms Imaging ◽  
Modified Peptides ◽  
Microbial Natural Products

<p>The utilisation of natural products for treatment of human ailments has been rooted in various cultures for centuries. Extraction of natural products has been essential for the discovery of new drugs and inspiration for synthetic analogues. Since the success of penicillin, microbial natural products have been of interest. Genome mining of Thermogemmatisporastrain T81, a thermophile from the Taupo Volcanic Zone, found the potential for the production of novel ribosomally synthesised and post-translationally modified peptides (RiPPs). Previous work showed that T81 exhibited antimicrobial activity against a wide variety of extremophillic bacteria. Although the three thiopeptides encoded forin the genome of T81 have not been found, the lanthipeptide tikitericin has recently been isolated and described. Unfortunately tikitericin is produced in low quantities by T81 andbioactivity data has not yet been obtained. Because of its potential antimicrobial activity, different routes to produce it are of interest. The aim of this project wasto synthesisetikitericin by solid phase peptide synthesis. MS imaging was also utilised to search for the presence of tikitericin as an antimicrobial agent in situ.</p>

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