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norskBlar i forfatter Artikler, rapporter og annet (Norges fiskerihøgskole) "Isaksson, Johan"
Viser treff 1-15 av 15
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Anti-Bacterial Effect and Cytotoxicity Assessment of Lipid 430 Isolated from Algibacter sp.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-05)Two bacterial isolates from the Barents Sea, both belonging to the genus <i>Algibacter</i>, were found to yield extracts with anti-bacterial bioactivity. Mass spectrometry guided dereplication and purification of the active extracts lead to the isolation of the same active principle in both extracts. The structure of the bioactive compound was identified via mass spectrometry and nuclear resonance ... -
Bioactivity of Serratiochelin A, a Siderophore Isolated from a Co-Culture of Serratia sp. and Shewanella sp.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-14)Siderophores are compounds with high affinity for ferric iron. Bacteria produce these compounds to acquire iron in iron-limiting conditions. Iron is one of the most abundant metals on earth, and its presence is necessary for many vital life processes. Bacteria from the genus <i>Serratia</i> contribute to the iron respiration in their environments, and previously several siderophores have been isolated ... -
Cellular Antioxidant Effect of Four Bromophenols from the Red Algae, Vertebrata lanosa
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Three known bromophenols, 2,3-dibromo-4,5-dihydroxybenzylaldehyde (1), 2,2′,3-tribromo-3′,4,4′,5-tetrahydroxy 6′-hydroxymethyldiphenylmethane (2) and bis(2, 3-dibromo-4,5-dihydroxylbenzyl) ether (3), and one new one, 5,5″-oxybis(methylene)bis (3-bromo-4-(2′,3′-dibromo-4′,5′-dihydroxylbenzyl)benzene-1,2-diol) (4), were isolated from an extract of the red alga, Vertebrata lanosa. The antioxidant ... -
Characterization of Rhamnolipids Produced by an Arctic Marine Bacterium from the Pseudomonas fluorescence Group
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-14)The marine environment is a rich source of biodiversity, including microorganisms that have proven to be prolific producers of bioactive secondary metabolites. Arctic seas are less explored than warmer, more accessible areas, providing a promising starting point to search for novel bioactive compounds. In the present work, an Arctic marine Pseudomonas sp. belonging to the Pseudomonas (P.) fluorescence ... -
Chlovalicin B, a Chlorinated Sesquiterpene Isolated from the Marine Mushroom Digitatispora marina
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-13)As part of our search for bioactive metabolites from understudied marine microorganisms, the new chlorinated metabolite chlovalicin B (1) was isolated from liquid cultures of the marine basidiomycete Digitatispora marina, which was collected and isolated from driftwood found at Vannøya, Norway. The structure of the novel compound was elucidated by spectroscopic methods including 1D and 2D NMR and ... -
Dendrobeaniamine A, a new alkaloid from the Arctic marine bryozoan Dendrobeania murrayana
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-20)The new guanidine alkaloid Dendrobeaniamine A (1) was isolated from the organic extract of the Arctic marine bryozoan <i>Dendrobeania murrayana</i>. The chemical structure of 1 was elucidated by spectroscopic experiments, including 1D and 2D NMR and HRESIMS analysis. Compound 1 is a lipoamino acid, consisting of a C<sub>12</sub> fatty acid anchored to the amino acid arginine. The bioactivity of 1 ... -
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 ... -
Kinase chemodiversity from the Arctic: the breitfussins
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-24)In this work, we demonstrate that the indole-oxazole-pyrrole framework of the breitfussin family of natural products is a promising scaffold for kinase inhibition. Six new halogenated natural products, breitfussin C–H (3 – 8) were isolated and characterized from the Arctic, marine hydrozoan Thuiaria breitfussi. The structures of two of the new natural products were also confirmed by total synthesis. ... -
Lulworthinone, a New Dimeric Naphthopyrone From a Marine Fungus in the Family Lulworthiaceae With Antibacterial Activity Against Clinical Methicillin-Resistant Staphylococcus aureus Isolates
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-01)The emergence of drug-resistant bacteria is increasing rapidly in all parts of the world, and the need for new antibiotics is urgent. In our continuous search for new antimicrobial molecules from under-investigated Arctic marine microorganisms, a marine fungus belonging to the family Lulworthiaceae (Lulworthiales, Sordariomycetes, and Ascomycota) was studied. The fungus was isolated from driftwood, ... -
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 ... -
A Novel Brominated Alkaloid Securidine A, Isolated from the Marine Bryozoan Securiflustra securifrons
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-23)A novel brominated alkaloid, Securidine A, was isolated from the cold water marine bryozoan Securiflustra securifrons. Securidine A was isolated using semi-preparative HPLC, and the structure was elucidated by spectroscopic methods. The isolated Securidine A was tested for cytotoxic, antibacterial, and anti-diabetic activities as well as for its potential for inhibition of biofilm formation. No ... -
A Novel brominated Alkaloid Securidine A, Isolated from the Marine Bryozoan Securiflustra securifrons
(Conference object; Konferansebidrag, 2017)A novel brominated alkaloid, Securidine A, was isolated from the cold water marine bryozoan Securiflustra securifrons. Securidine A was isolated using semi-preparative HPLC, and the structure was elucidated by spectroscopic methods. The isolated Securidine A was tested for cytotoxic, antibacterial, and anti-diabetic activities as well as for its potential for inhibition of biofilm formation. No ... -
Ponasterone A and F, Ecdysteroids from the Arctic Bryozoan Alcyonidium gelatinosum
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-19)A new ecdysteroid, ponasterone F (1) and the previously reported compound ponasterone A (2) were isolated from specimens of the Arctic marine bryozoan Alcyonidium gelatinosum collected at Hopenbanken, off the coast of Edgeøya, Svalbard. The structure of 1 was elucidated, and the structure of 2 confirmed by spectroscopic methods including 1D and 2D NMR and analysis of HR-MS data. The compounds were ... -
Two Novel Lyso-Ornithine Lipids Isolated from an Arctic Marine Lacinutrix sp. Bacterium
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-31)The Lacinutrix genus was discovered in 2005 and includes 12 Gram-negative bacterial species. To the best of our knowledge, the secondary metabolite production potential of this genus has not been explored before, and examination of Lacinutrix species may reveal novel chemistry. As part of a screening project of Arctic marine bacteria, the Lacinutrix sp. strain M09B143 was cultivated, extracted, ...
