scholarly journals Synthesis and antimicrobial activity of some novel 1,2-dihydro-[1,2,4]triazolo[1,5-a]pyrimidines bearing amino acid moiety

RSC Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 2905-2916
Author(s):  
Mounir A. A. Mohamed ◽  
Adnan A. Bekhit ◽  
Omyma A. Abd Allah ◽  
Asmaa M. Kadry ◽  
Tamer M. Ibrahim ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Green Chemistry ◽  
Antimicrobial Activities ◽  
Amino Acid Derivatives ◽  
Acid Moiety ◽  
Amino Acid Moiety

A new series of [1,2,4]-triazole bearing amino acid derivatives were synthesized under green chemistry conditions and evaluated for their antimicrobial activities.

Lossen Rearrangement by Rh(III)-Catalyzed C-H Activation/Annulation of Aryl Hydroxamates with Alkynes: Access to Quinolone-containing Amino Acid Derivatives

2021 ◽  
Author(s):  
Dmitry A. Petropavlovskikh ◽  
Daria Vorobyeva ◽  
Ivan A. Godovikov ◽  
Sergey E Nefedov ◽  
Oleg A. Filippov ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Derivatives ◽  
Robust Method ◽  
Acid Moiety ◽  
Internal Alkynes ◽  
Amino Acid Moiety

A convenient and robust method for the preparation of new CF3-containing 2-quinolones has been developed via Rh(III)-catalyzed C-H activation/Lossen rearrangement/annulation cascade of N-pivaloyloxy-arylamides with internal alkynes bearing α-CF3-α-amino acid moiety...

scholarly journals Development of Antimicrobial Stapled Peptides Based on Magainin 2 Sequence

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 444
Author(s):  
Motoharu Hirano ◽  
Chihiro Saito ◽  
Hidetomo Yokoo ◽  
Chihiro Goto ◽  
Ryuji Kawano ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Hemolytic Activity ◽  
Helical Structure ◽  
Antimicrobial Activities ◽  
Side Chain ◽  
Membrane Disruption ◽  
Amino Acid Residues ◽  
Electrophysiological Measurements ◽  
Cell Membrane Disruption

Magainin 2 (Mag2), which was isolated from the skin of the African clawed frog, is a representative antimicrobial peptide (AMP) that exerts antimicrobial activity via microbial membrane disruption. It has been reported that the helicity and amphipathicity of Mag2 play important roles in its antimicrobial activity. We investigated and recently reported that 17 amino acid residues of Mag2 are required for its antimicrobial activity, and accordingly developed antimicrobial foldamers containing α,α-disubstituted amino acid residues. In this study, we further designed and synthesized a set of Mag2 derivatives bearing the hydrocarbon stapling side chain for helix stabilization. The preferred secondary structures, antimicrobial activities, and cell-membrane disruption activities of the synthesized peptides were evaluated. Our analyses revealed that hydrocarbon stapling strongly stabilized the helical structure of the peptides and enhanced their antimicrobial activity. Moreover, peptide 2 stapling between the first and fifth position from the N-terminus showed higher antimicrobial activity than that of Mag2 against both gram-positive and gram-negative bacteria without exerting significant hemolytic activity. To investigate the modes of action of tested peptides 2 and 8 in antimicrobial and hemolytic activity, electrophysiological measurements were performed.

scholarly journals Biological and Physico-Chemical Characteristics of Arginine-Rich Peptide Gemini Surfactants with Lysine and Cystine Spacers

2021 ◽  
Vol 22 (7) ◽  
pp. 3299
Author(s):  
Damian Neubauer ◽  
Maciej Jaśkiewicz ◽  
Marta Bauer ◽  
Agata Olejniczak-Kęder ◽  
Emilia Sikorska ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Cationic Surfactants ◽  
Antimicrobial Agents ◽  
Gemini Surfactants ◽  
Antimicrobial Activities ◽  
Critical Aggregation Concentration ◽  
Cytotoxic Activities ◽  
Candida Sp ◽  
Enhanced Selectivity

Ultrashort cationic lipopeptides (USCLs) and gemini cationic surfactants are classes of potent antimicrobials. Our recent study has shown that the branching and shortening of the fatty acids chains with the simultaneous addition of a hydrophobic N-terminal amino acid in USCLs result in compounds with enhanced selectivity. Here, this approach was introduced into arginine-rich gemini cationic surfactants. L-cystine diamide and L-lysine amide linkers were used as spacers. Antimicrobial activity against planktonic and biofilm cultures of ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) strains and Candida sp. as well as hemolytic and cytotoxic activities were examined. Moreover, antimicrobial activity in the presence of human serum and the ability to form micelles were evaluated. Membrane permeabilization study, serum stability assay, and molecular dynamics were performed. Generally, critical aggregation concentration was linearly correlated with hydrophobicity. Gemini surfactants were more active than the parent USCLs, and they turned out to be selective antimicrobial agents with relatively low hemolytic and cytotoxic activities. Geminis with the L-cystine diamide spacer seem to be less cytotoxic than their L-lysine amide counterparts, but they exhibited lower antibiofilm and antimicrobial activities in serum. In some cases, geminis with branched fatty acid chains and N-terminal hydrophobic amino acid resides exhibited enhanced selectivity to pathogens over human cells.

scholarly journals Diverse Mechanisms of Antimicrobial Activities of Lactoferrins, Lactoferricins, and Other Lactoferrin-Derived Peptides

2021 ◽  
Vol 22 (20) ◽  
pp. 11264
Author(s):  
Špela Gruden ◽  
Nataša Poklar Ulrih
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Molecular Level ◽  
Antioxidant Activities ◽  
Antimicrobial Activities ◽  
Iron Binding ◽  
Primary Focus ◽  
Binding Glycoprotein

Lactoferrins are an iron-binding glycoprotein that have important protective roles in the mammalian body through their numerous functions, which include antimicrobial, antitumor, anti-inflammatory, immunomodulatory, and antioxidant activities. Among these, their antimicrobial activity has been the most studied, although the mechanism behind antimicrobial activities remains to be elucidated. Thirty years ago, the first lactoferrin-derived peptide was isolated and showed higher antimicrobial activity than the native lactoferrin lactoferricin. Since then, numerous studies have investigated the antimicrobial potencies of lactoferrins, lactoferricins, and other lactoferrin-derived peptides to better understand their antimicrobial activities at the molecular level. This review defines the current antibacterial, antiviral, antifungal, and antiparasitic activities of lactoferrins, lactoferricins, and lactoferrin-derived peptides. The primary focus is on their different mechanisms of activity against bacteria, viruses, fungi, and parasites. The role of their structure, amino-acid composition, conformation, charge, hydrophobicity, and other factors that affect their mechanisms of antimicrobial activity are also reviewed.

scholarly journals Acrylamide Formation in Food: A Mechanistic Perspective

2005 ◽  
Vol 88 (1) ◽  
pp. 262-267 ◽  
Author(s):  
Varoujan A Yaylayan ◽  
Richard H Stadler
Keyword(s):  
Amino Acid ◽  
Carbonyl Compounds ◽  
Azomethine Ylide ◽  
Significant Progress ◽  
Acid Moiety ◽  
Sugar Moiety ◽  
Acrylamide Formation ◽  
Amino Acid Moiety ◽  
Strecker Aldehyde

Abstract Earliest reports on the origin of acrylamide in food have confirmed asparagine as the main amino acid responsible for its formation. Available evidence suggests that sugars and other carbonyl compounds play a specific role in the decarboxylation process of asparagine, a necessary step in the generation of acrylamide. It has been proposed that Schiff base intermediate formed between asparagine and the sugar provides a low energy alternative to the decarboxylation from the intact Amadori product through generation and decomposition of oxazolidin-5-one intermediate, leading to the formation of a relatively stable azomethine ylide. Literature data indicate the propensity of such protonated ylides to undergo irreversible 1,2-prototropic shift and produce, in this case, decarboxylated Schiff bases which can easily rearrange into E Decarboxylated Amadori products can either undergo the well known β-elimination process initiated by the sugar moiety to produce 3-aminopropanamide and 1-deoxyglucosone or undergo 1,2-elimination initiated by the amino acid moiety to directly generate acrylamide. On the other hand, the Schiff intermediate can either hydrolyze and release 3-aminopropanamide or similarly undergo amino acid initiated 1,2-elimination to directly form acrylamide. Other thermolytic pathways to acrylamide—considered marginal at this stage—via the Strecker aldehyde, acrolein, and acrylic acid, are also addressed. Despite significant progress in the understanding of the mechanistic aspects of acrylamide formation, concrete evidence for the role of the different proposed intermediates in foods is still lacking.

Design, Synthesis and Insecticidal Evaluation of Anthranilic Diamides Containing Optically Pure Amino Acid Moiety

2016 ◽  
Vol 34 (12) ◽  
pp. 1218-1224 ◽  
Author(s):  
Shaa Zhou ◽  
Sha Zhou ◽  
Xuewen Hua ◽  
Wei Wei ◽  
Yongtao Xie ◽  
...  
Keyword(s):  
Amino Acid ◽  
Acid Moiety ◽  
Design Synthesis ◽  
Amino Acid Moiety ◽  
Pure Amino Acid ◽  
Optically Pure
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