- Metabolomics-Guided Discovery of Microginin Peptides from Cultures of the Cyanobacterium Microcystis aeruginosa
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We report a mass-spectrometry-based metabolomics study of a laboratory-cultured strain of Microcystis aeruginosa (UTEX LB2385), which has led to the discovery of five peptides (1-5) belonging to the microginin class of linear cyanopeptides. The structures and configurations of these peptides were determined by spectroscopic analyses and chemical derivitization. The microginin peptides described herein are the first reported derivatives containing N-methyl methionine (1, 5) and N-methyl methionine sulfoxide (2-4). The two tripeptide microginin analogues (4, 5) identified represent the smallest members of this peptide family. Their angiotensin-converting enzyme (ACE) inhibitory activity was also investigated. Microginin 527 (4) was the most potent of the group, with an IC50 of 31 μM.
- Stewart, Allison K.,Ravindra, Rudravajhala,Van Wagoner, Ryan M.,Wright, Jeffrey L. C.
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- Peptide carbocyclic derivatives as inhibitors of the viroporin function of RNA-containing viruses
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New carbocyclic derivatives of amino acids, peptides, and other compounds have been synthesized, and their antiviral activity toward the influenza A/H5N1 and hepatitis C viruses has been studied in vitro. It has been shown that the aminoacyl derivatives of aminoadamantane are capable of inhibiting the replication of the highly virulent strain of the avian influenza virus (H5N1), which is resistant to aminoadamantanes amantadine and rimantadine. The effect of the configuration of the carbocyclic moiety of the dipeptide H-Pro-Trp-OH on the antiviral properties toward the hepatitis C virus has been studied. The cyclohexyloxycarbonyl derivative of the H-Pro-Trp-OH dipeptide strongly inhibited the replication of HCV in vitro. Some compounds have been found to exhibit a high virucidal activity toward influenza A/H5N1 and HCV virions.
- Shibnev,Deryabin,Garaev,Finogenova,Botikov,Mishin
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p. 517 - 525
(2017/09/27)
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- Resolution of the Confusion in the Assignments of Configuration for the Ciliatamides, Acylated Dipeptides from Marine Sponges
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Direct comparison of authentic ciliatamide A with four synthetic isomers (1-4) by means of NMR and chiral-phase HPLC revealed that ciliatamide A possesses the 12R (d-N-MePhe residue) and 22S (l-Lys residue) configurations, which were not identical with either our previous assignment or those proposed by others through total synthesis. The absolute configuration of the methionine sulfoxide residue in ciliatamide D was also revised to be d.
- Takada, Kentaro,Irie, Raku,Suo, Rei,Matsunaga, Shigeki
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p. 2845 - 2849
(2017/11/06)
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- Isolation of ciliatamide D from a marine sponge Stelletta sp. and a reinvestigation of the configuration of ciliatamide A
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A new lipopeptide, ciliatamide D (1), was isolated from a marine sponge Stelletta sp., collected at Oshimashinsone, together with the known compound ciliatamide A (2). Ciliatamide D (1) is a congener of 2, in which N-Me-Phe is replaced by N-Me-Met(O). Marfey's analysis of the acid hydrolysate of 1 demonstrated that the two constituent amino acids were both in the l-form. This result prompted us to carefully investigate the configuration of 2, resulting in the assignment of the l-form for both residues.
- Imae, Yasufumi,Takada, Kentaro,Okada, Shigeru,Ise, Yuji,Yoshimura, Hiroshi,Morii, Yasuhiro,Matsunaga, Shigeki
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p. 755 - 758
(2013/06/05)
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- On the transport of tripeptide antibiotics in bacteria
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The two tripeptide antibiotics L 2 amino 4 methylphosphinobutyryl alanyl alanine (L phosphinothricyl alanyl alanine) and L (N5 phosphono)methionine S sulfoximinyl alanyl alanine, both inhibitors of the glutamine synthetase, are transported into the cell of Escherichia coli K 12 via the oligopeptide transport system. The uptake by this system is proved first of all by cross resistance with tri L ornithine using oligopeptide transport deficient mutants, and secondly by antagonism tests demonstrating competitive reversal of the action of the antibiotic by several peptides which have been shown to be transported via the oligopeptide transport system, e.g. tri L alanine, tetra L alanine, tri L lysine, tri L serine, tri glycine, glycyl glycyl L alanine and the synthetic tripeptide L azaadenylaminohexanoyl alanyl alanine. On the other hand, there is no effect on the action of the antibiotic in antagonism tests with compounds which use different transport systems, such as L alanyl alanine, L lysyl lysine, glutathione and the synthetic amino acid azaadenylaminohexanoic acid, i.e. 2 amino 6 (7 amino 3H v triazolo [4,5 d] pyrimidin 3 yl)hexanoic acid. Another inhibitor of the glutamine synthetase, L methionine S dioxide (methioninesulfone) could be converted into a tripeptide form by linkage to L alanyl alanine analogously to the tripeptide antibiotics described above. Whereas the free L methionine S dioxide seems to be transported via the methionine transport system, the tripeptide form is transported via the oligopeptide transport system. Thus, this glutamine synthetase inhibitor can be taken up by the cell via two different transport mechanisms. These results indicate that this could provide a synergistic effect. The syntheses of the new tripeptides L azaadenylaminohexanoyl alanyl alanine and L methionine S dioxidyl alanyl alanine were performed by dicyclohexylcarbodiimide couplings of the unusual N protected L α amino acids azaadenylaminohexanoic acid and L methionine S dioxide to L alanyl alanine tert butyl ester followed by common deprotection steps. Tri L ornithine was synthesized without carboxyl protection via two successive couplings of hydroxybenzotriazol esters of N(α)butoxycarbonyl N(δ)benzyloxycarbonyl L ornithine to N(δ)benzyloxycarbonyl L ornithine.
- Diddens,Zaehner,Kraas,Goehring,Jung
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