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Structural Characterization of New Peptide Variants Produced by Cyanobacteria from the Brazilian Atlantic Coastal Forest Using Liquid Chromatography Coupled to Quadrupole Time-of-Flight Tandem Mass Spectrometry.

Sanz M, Andreote AP, Fiore MF, Dörr FA, Pinto E - Mar Drugs (2015)

Bottom Line: Of the 38 peptides, 37 were detected here for the first time.New structural features were proposed based on mass accuracy data and isotopic patterns derived from full scan and MS/MS spectra.Interestingly, of the 40 surveyed strains only nine were confirmed to be peptide producers; all of these strains belonged to the order Nostocales (three Nostoc sp., two Desmonostoc sp. and four Brasilonema sp.).

View Article: PubMed Central - PubMed

Affiliation: Faculty of Pharmaceutical Science, University of São Paulo, Avenida Lineu Prestes 580, Bl-17-05508-900 São Paulo, SP, Brazil. miriam.sanz.roldan@usp.br.

ABSTRACT
Cyanobacteria from underexplored and extreme habitats are attracting increasing attention in the search for new bioactive substances. However, cyanobacterial communities from tropical and subtropical regions are still largely unknown, especially with respect to metabolite production. Among the structurally diverse secondary metabolites produced by these organisms, peptides are by far the most frequently described structures. In this work, liquid chromatography/electrospray ionization coupled to high resolution quadrupole time-of-flight tandem mass spectrometry with positive ion detection was applied to study the peptide profile of a group of cyanobacteria isolated from the Southeastern Brazilian coastal forest. A total of 38 peptides belonging to three different families (anabaenopeptins, aeruginosins, and cyanopeptolins) were detected in the extracts. Of the 38 peptides, 37 were detected here for the first time. New structural features were proposed based on mass accuracy data and isotopic patterns derived from full scan and MS/MS spectra. Interestingly, of the 40 surveyed strains only nine were confirmed to be peptide producers; all of these strains belonged to the order Nostocales (three Nostoc sp., two Desmonostoc sp. and four Brasilonema sp.).

No MeSH data available.


Related in: MedlinePlus

(a) Product ion spectrum for [M + H]+ of compound 37 and (b) its predicted fragmentation pattern. Conditions as described in the experimental section.
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marinedrugs-13-03892-f005: (a) Product ion spectrum for [M + H]+ of compound 37 and (b) its predicted fragmentation pattern. Conditions as described in the experimental section.

Mentions: Figure 5 shows the proposed depsipeptide cyclic structure for compound 37 (Ac-Pro-Gln[Thr-Leu-Ahp-Leu-NMe-OMe-Tyr-Leu]) and its predicted fragmentation pattern. The most abundant ions observed in the product ion spectrum of this compound were attributed to the loss of amino acid residues from the C-terminus (m/z 881.4576, 690.3777, 464.2468, 351.1633, and 268.1271) of the dehydrated protonated molecule at m/z 994.5553. This precursor ion was suggested to be generated by the cleavage of the ester linkage accompanied by the dehydration of the Thr [34]. Further loss of the acetyl-proline-glutamine side chain from this linear ion was also noted (m/z 727.4318). Simultaneously, evidence of dehydration at the Ahp position was observed at m/z 400.2184 and 786.4305. An inspection of the low m/z region of the spectrum also supported the proposed structure, revealing the presence of ions associated with the amino acids Ahp (m/z 209.1286 and 181.1300), NMeOMeTyr (m/z 164.1052), AcPro (m/z 112.0679 and 140.0703), Leu (m/z 86.0979), and Pro (m/z 70.0563). To our knowledge, the N-acetyl-proline-glutamine side chain has not been


Structural Characterization of New Peptide Variants Produced by Cyanobacteria from the Brazilian Atlantic Coastal Forest Using Liquid Chromatography Coupled to Quadrupole Time-of-Flight Tandem Mass Spectrometry.

Sanz M, Andreote AP, Fiore MF, Dörr FA, Pinto E - Mar Drugs (2015)

(a) Product ion spectrum for [M + H]+ of compound 37 and (b) its predicted fragmentation pattern. Conditions as described in the experimental section.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4483662&req=5

marinedrugs-13-03892-f005: (a) Product ion spectrum for [M + H]+ of compound 37 and (b) its predicted fragmentation pattern. Conditions as described in the experimental section.
Mentions: Figure 5 shows the proposed depsipeptide cyclic structure for compound 37 (Ac-Pro-Gln[Thr-Leu-Ahp-Leu-NMe-OMe-Tyr-Leu]) and its predicted fragmentation pattern. The most abundant ions observed in the product ion spectrum of this compound were attributed to the loss of amino acid residues from the C-terminus (m/z 881.4576, 690.3777, 464.2468, 351.1633, and 268.1271) of the dehydrated protonated molecule at m/z 994.5553. This precursor ion was suggested to be generated by the cleavage of the ester linkage accompanied by the dehydration of the Thr [34]. Further loss of the acetyl-proline-glutamine side chain from this linear ion was also noted (m/z 727.4318). Simultaneously, evidence of dehydration at the Ahp position was observed at m/z 400.2184 and 786.4305. An inspection of the low m/z region of the spectrum also supported the proposed structure, revealing the presence of ions associated with the amino acids Ahp (m/z 209.1286 and 181.1300), NMeOMeTyr (m/z 164.1052), AcPro (m/z 112.0679 and 140.0703), Leu (m/z 86.0979), and Pro (m/z 70.0563). To our knowledge, the N-acetyl-proline-glutamine side chain has not been

Bottom Line: Of the 38 peptides, 37 were detected here for the first time.New structural features were proposed based on mass accuracy data and isotopic patterns derived from full scan and MS/MS spectra.Interestingly, of the 40 surveyed strains only nine were confirmed to be peptide producers; all of these strains belonged to the order Nostocales (three Nostoc sp., two Desmonostoc sp. and four Brasilonema sp.).

View Article: PubMed Central - PubMed

Affiliation: Faculty of Pharmaceutical Science, University of São Paulo, Avenida Lineu Prestes 580, Bl-17-05508-900 São Paulo, SP, Brazil. miriam.sanz.roldan@usp.br.

ABSTRACT
Cyanobacteria from underexplored and extreme habitats are attracting increasing attention in the search for new bioactive substances. However, cyanobacterial communities from tropical and subtropical regions are still largely unknown, especially with respect to metabolite production. Among the structurally diverse secondary metabolites produced by these organisms, peptides are by far the most frequently described structures. In this work, liquid chromatography/electrospray ionization coupled to high resolution quadrupole time-of-flight tandem mass spectrometry with positive ion detection was applied to study the peptide profile of a group of cyanobacteria isolated from the Southeastern Brazilian coastal forest. A total of 38 peptides belonging to three different families (anabaenopeptins, aeruginosins, and cyanopeptolins) were detected in the extracts. Of the 38 peptides, 37 were detected here for the first time. New structural features were proposed based on mass accuracy data and isotopic patterns derived from full scan and MS/MS spectra. Interestingly, of the 40 surveyed strains only nine were confirmed to be peptide producers; all of these strains belonged to the order Nostocales (three Nostoc sp., two Desmonostoc sp. and four Brasilonema sp.).

No MeSH data available.


Related in: MedlinePlus