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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.


Product ion spectra for [M + H]+ of compound 14 at (a) CE: 35 eV; (b) CE: 50 eV; and (c) CE: 70 eV; and (d) compound 21 at CE 35 eV.
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marinedrugs-13-03892-f004: Product ion spectra for [M + H]+ of compound 14 at (a) CE: 35 eV; (b) CE: 50 eV; and (c) CE: 70 eV; and (d) compound 21 at CE 35 eV.

Mentions: The detected anabaenopeptins could be grouped according to their structural features. Among these compounds, 10 anabaenopeptins that shared similar structural characteristics were detected in Desmonostoc sp. CENA360 and Brasilonema sp. CENA386 (12–17, 22, 25–27). The representative fragmentation pathways and spectra of these compounds are described in Figure 3 and Figure 4, and the assignments of the principal ions are shown in Table 6, Table 7, Table 8 and Table 9. Since the nature of the exocyclic amino acid varies among them, two different fragmentation patterns were observed for these compounds depending on the nature of the amino acid side chain. Extensive fragmentation was observed due to the absence of polar and basic residues in this chain. These anabaenopeptins commonly incorporate the amino acid N-methyl asparagine (N-MeAsn) in position 5, and on several occasions, either methylation or ethylation was postulated for the homovariant amino acid in position 4.


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)

Product ion spectra for [M + H]+ of compound 14 at (a) CE: 35 eV; (b) CE: 50 eV; and (c) CE: 70 eV; and (d) compound 21 at CE 35 eV.
© Copyright Policy
Related In: Results  -  Collection

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

marinedrugs-13-03892-f004: Product ion spectra for [M + H]+ of compound 14 at (a) CE: 35 eV; (b) CE: 50 eV; and (c) CE: 70 eV; and (d) compound 21 at CE 35 eV.
Mentions: The detected anabaenopeptins could be grouped according to their structural features. Among these compounds, 10 anabaenopeptins that shared similar structural characteristics were detected in Desmonostoc sp. CENA360 and Brasilonema sp. CENA386 (12–17, 22, 25–27). The representative fragmentation pathways and spectra of these compounds are described in Figure 3 and Figure 4, and the assignments of the principal ions are shown in Table 6, Table 7, Table 8 and Table 9. Since the nature of the exocyclic amino acid varies among them, two different fragmentation patterns were observed for these compounds depending on the nature of the amino acid side chain. Extensive fragmentation was observed due to the absence of polar and basic residues in this chain. These anabaenopeptins commonly incorporate the amino acid N-methyl asparagine (N-MeAsn) in position 5, and on several occasions, either methylation or ethylation was postulated for the homovariant amino acid in position 4.

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.