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Amphipathic Barbiturates as Mimics of Antimicrobial Peptides and the Marine Natural Products Eusynstyelamides with Activity against Multi-resistant Clinical Isolates
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-27)We report a series of synthetic cationic amphipathic barbiturates inspired by the pharmacophore model of small antimicrobial peptides (AMPs) and the marine antimicrobials eusynstyelamides. These N,N′-dialkylated-5,5-disubstituted barbiturates consist of an achiral barbiturate scaffold with two cationic groups and two lipophilic side chains. Minimum inhibitory concentrations of 2–8 μg/mL were achieved ... -
Anti-infectious and anti-inflammatory effects of peptide fragments sequentially derived from the antimicrobial peptide centrocin 1 isolated from the green sea urchin, Strongylocentrotus droebachiensis
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012)Bacterial resistance against antibiotic treatment has become a major threat to public health. Antimicrobial peptides (AMPs) have emerged as promising alternative agents for treatment of infectious diseases. This study characterizes novel synthetic peptides sequentially derived from the AMP centrocin 1, isolated from the green sea urchin, for their applicability as anti-infective agents.The microbicidal ... -
Antimicrobial activity of amphipathic α,α-disubstituted β-amino amide derivatives against ESBL–CARBA producing multi-resistant bacteria; effect of halogenation, lipophilicity and cationic character
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-06)The rapid emergence and spread of multi-resistant bacteria have created an urgent need for new antimicrobial agents. We report here a series of amphipathic α,α-disubstituted β-amino amide derivatives with activity against 30 multi-resistant clinical isolates of Gram-positive and Gram-negative bacteria, including isolates with extended spectrum β-lactamase – carbapenemase (ESBL-CARBA) production. A ... -
Antimicrobial activity of small synthetic peptides based on the marine peptide turgencin A: Prediction of antimicrobial peptide sequences in a natural peptide and strategy for optimization of potency
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-30)Turgencin A, a potent antimicrobial peptide isolated from the Arctic sea squirt <i>Synoicum turgens</i>, consists of 36 amino acid residues and three disulfide bridges, making it challenging to synthesize. The aim of the present study was to develop a truncated peptide with an antimicrobial drug lead potential based on turgencin A. The experiments consisted of: (1) sequence analysis and prediction ... -
Antimicrobial peptides in echinoderm host defense
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-11-06)Antimicrobial peptides (AMPs) are important effector molecules in innate immunity. Here we briefly summarize characteristic traits of AMPs and their mechanisms of antimicrobial activity. Echinoderms live in a microbe-rich marine environment and are known to express a wide range of AMPs. We address two novel AMP families from coelomocytes of sea urchins: cysteine-rich AMPs (strongylocins) and ... -
Antimicrobial Peptides in Echinoderms
(Journal article; Tidsskriftartikkel; Peer reviewed, 2010) -
Autofluorescence mediated red spherulocyte sorting provides insights into the source of spinochromes in sea urchins
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-24)Red spherule cells (RSCs) are considered one of the prime immune cells of sea urchins, but their detailed biological role during immune responses is not well elucidated. Lack of pure populations accounts for one of the major challenges of studying these cells. In this study, we have demonstrated that live RSCs exhibit strong, multi-colour autofluorescence distinct from other coelomocytes, and with ... -
Chemical and Enzyme-Assisted Extraction of Fucoidan from two Species of Brown Macroalgae (Ascophyllum nodosum and Saccharina latissima)
(Conference object; Konferansebidrag, 2022)Macroalgae are vital species and are known to produce a wide range of bioactive compounds including polysaccharides, such as fucoidan. Traditionally, these compounds are extracted using hazardous solvents that leads to environmental pollution and waste. Considering this, more sustainable technologies are being investigated as greener alternatives.<p> <p>The main goal of this study was to ... -
A concise SAR-analysis of antimicrobial cationic amphipathic barbiturates for an improved activity-toxicity profile
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-05)An amphipathic barbiturate mimic of the marine eusynstyelamides is reported as a promising class of antimicrobial agents. We hereby report a detailed analysis of the structure-activity relationship for cationic amphipathic N,N′ -dialkylated-5,5-disubstituted barbiturates. The influence of various cationic groups, hydrocarbon linkers and lipophilic side chains on the compounds’ antimicrobial potency ... -
Expression of antimicrobial peptides in coelomocytes and embryos of the green sea urchin (Strongylocentrotus droebachiensis)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013-11-12)Antimicrobial peptides (AMPs) play a crucial role in innate immunity. We have previously reported the isolation and characterization of the AMPs, strongylocins 1 and 2, and centrocin 1, from coelomocyte extracts of Strongylocentrotus droebachiensis. Here we show that these AMPs were expressed in phagocytes. In addition, transcripts of strongylocin 1 were detected in vibratile cells and/or colorless ... -
Investigation of tetrasubstituted heterocycles reveals hydantoins as a promising scaffold for development of novel antimicrobials with membranolytic properties
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-24)Mimics of antimicrobial peptides (AMPs) have been proposed as a promising class of antimicrobial agents. We report the analysis of five tetrasubstituted, cationic, amphipathic heterocycles as potential AMP mimics. The analysis showed that the heterocyclic scaffold had a strong influence on the haemolytic activity of the compounds, and the hydantoin scaffold was identified as a promising template for ... -
Isolation and characterization of antimicrobial peptides with unusual disulfide connectivity from the colonial ascidian Synoicum turgens
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-12)This study reports the isolation of two novel cysteine-rich antibacterial peptides, turgencin A and turgencin B, along with their oxidized derivatives, from the Arctic marine colonial ascidian <i>Synoicum turgens</i>. The peptides are post-translationally modified, containing six cysteines with an unusual disulfide connectivity of Cys<sup>1</sup>-Cys<sup>6</sup>, Cys<sup>2</sup>-Cys<sup>5</sup>, and ... -
Isolation and Characterization of Antimicrobial Peptides with Unusual Disulfide Connectivity from the Colonial Ascidian Synoicum turgens
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-12)This study reports the isolation of two novel cysteine-rich antibacterial peptides, turgencin A and turgencin B, along with their oxidized derivatives, from the Arctic marine colonial ascidian <i>Synoicum turgens</i>. The peptides are post-translationally modified, containing six cysteines with an unusual disulfide connectivity of Cys<sup>1</i>-Cys<sup>6</sup>, Cys<sup>2</sup>-Cys<sup>5</sup>, and ... -
Isolation and Synthesis of Pulmonarins A and B, Acetylcholinesterase Inhibitors from the Colonial Ascidian Synoicum pulmonaria
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-02-14)Pulmonarins A and B are two new dibrominated marine acetylcholinesterase inhibitors that were isolated and characterized from the sub-Arctic ascidian <i>Synoicum pulmonaria</i> collected off the Norwegian coast. The structures of natural pulmonarins A and B were tentatively elucidated by spectroscopic methods and later verified by comparison with synthetically prepared material. Both pulmonarins A ... -
New Disulfide-Stabilized Fold Provides Sea Anemone Peptide to Exhibit Both Antimicrobial and TRPA1 Potentiating Properties
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-29)A novel bioactive peptide named τ-AnmTx Ueq 12-1 (short name Ueq 12-1) was isolated and characterized from the sea anemone Urticina eques. Ueq 12-1 is unique among the variety of known sea anemone peptides in terms of its primary and spatial structure. It consists of 45 amino acids including 10 cysteine residues with an unusual distribution and represents a new group of sea anemone peptides. The 3D ... -
Novel antimicrobial peptides EeCentrocins 1, 2 and EeStrongylocin 2 from the Edible sea urchin Echinus esculentus have 6-br-trp post-translational modifications
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-03-23)The global problem of microbial resistance to antibiotics has resulted in an urgent need to develop new antimicrobial agents. Natural antimicrobial peptides are considered promising candidates for drug development. Echinoderms, which rely on innate immunity factors in the defence against harmful microorganisms, are sources of novel antimicrobial peptides. This study aimed to isolate and characterise ... -
Paralithocins, Antimicrobial Peptides with Unusual Disulfide Connectivity from the Red King Crab, Paralithodes camtschaticus
(Journal article; Tidsskriftartikkel, 2018-01-17)As part of an ongoing exploration of marine invertebrates as a source of new antimicrobial peptides, hemocyte extracts from the red king crab, <i>Paralithodes camtschaticus</i>, were studied. Three cationic cysteine (Cys)-rich peptides, named paralithocins 1–3, were isolated by bioassay-guided purification, and their amino acid sequences determined by Edman degradation and expressed sequences tag ... -
Screening for antibacterial and antifungal activities in marine benthic invertebrates from northern Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2008-06-18)Benthic marine invertebrates collected from sub-Arctic regions of northern Norway, were found to be a promising source of novel bioactive compounds against human and fish pathogenic bacteria and fungi. Lyophilized material from seven species of ascidians, six sponges and one soft alcyonid coral were extracted with 60% acidified acetonitrile (ACN). After separation into an ACN-rich phase (ACN extract) ... -
Structure-activity relationships of the antimicrobial peptide arasin 1 - and mode of action studies of the N terminal, proline-rich region
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012)Arasin 1 is a 37 amino acid long proline-rich antimicrobial peptide isolated from the spider crab, Hyas araneus. In this work the active region of arasin 1 was identified through structure-activity studies using different peptide fragments derived from the arasin 1 sequence. The pharmacophore was found to be located in the proline/arginine-rich NH2 terminus of the peptide and the fragment arasin ... -
Synthesis and Antimicrobial Activity of Short Analogues of the Marine Antimicrobial Peptide Turgencin A: Effects of SAR Optimizations, Cys-Cys Cyclization and Lipopeptide Modifications
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-10)We have synthesised short analogues of the marine antimicrobial peptide Turgencin A from the colonial Arctic ascidian Synoicum turgens. In this study, we focused on a central, cationic 12-residue Cys-Cys loop region within the sequence. Modified (tryptophan- and arginine-enriched) linear peptides were compared with Cys-Cys cyclic derivatives, and both linear and Cys-cyclic peptides were N-terminally ...
