Limits...
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

Product ion spectrum for [M + H]+ of compound 7 and its predicted fragmentation pattern. Conditions as mentioned in the experimental section.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4483662&req=5

marinedrugs-13-03892-f002: Product ion spectrum for [M + H]+ of compound 7 and its predicted fragmentation pattern. Conditions as mentioned in the experimental section.

Mentions: The aeruginosins found in these extracts were characterized by closely related structures, most of which were common to both Nostoc and Brasilonema producer species. The most prominent peak detected in the MS chromatogram of these extracts (7) was assigned to the aeruginosin 865 (m/z 865.4565 [M + H]+) [37]. This compound, which was recently isolated from a terrestrial cyanobacterium belonging to Nostoc sp., was structurally characterized as containing both a fatty acid and a carbohydrate attached to the Choi moiety [37]. Figure 2 shows the product ion spectra of this aeruginosin. A collision energy of 70 eV was necessary to obtain a spectrum with abundant and intense product ions. Consistent with the existence of an agmatine (Agma) residue in the molecule, the C-terminal ions (m/z 588.3249, 412.2912, and 297.1989) and the corresponding satellite ions, which were produced via ammonia or water loss (m/z 571.2985, 395.2657, 279.1820, and 261.1717) dominated the spectrum. Additionally, the ions generated by the cleavage of the glycosidic acid and/or the ester bond established the sugar and the lipid acids as glucuronic acid and hexanoic acid, respectively. The presence of ions at m/z 18 u higher (m/z 156.1035 and 138.0866) than the diagnostic ions that are typically generated from the Choi residue (m/z 140 and 122) indicated the dihydroxylation of the indole ring in this amino acid and were key fragments for the detection of other aeruginosin congeners.


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 spectrum for [M + H]+ of compound 7 and its predicted fragmentation pattern. Conditions as mentioned in the experimental section.
© Copyright Policy
Related In: Results  -  Collection

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

marinedrugs-13-03892-f002: Product ion spectrum for [M + H]+ of compound 7 and its predicted fragmentation pattern. Conditions as mentioned in the experimental section.
Mentions: The aeruginosins found in these extracts were characterized by closely related structures, most of which were common to both Nostoc and Brasilonema producer species. The most prominent peak detected in the MS chromatogram of these extracts (7) was assigned to the aeruginosin 865 (m/z 865.4565 [M + H]+) [37]. This compound, which was recently isolated from a terrestrial cyanobacterium belonging to Nostoc sp., was structurally characterized as containing both a fatty acid and a carbohydrate attached to the Choi moiety [37]. Figure 2 shows the product ion spectra of this aeruginosin. A collision energy of 70 eV was necessary to obtain a spectrum with abundant and intense product ions. Consistent with the existence of an agmatine (Agma) residue in the molecule, the C-terminal ions (m/z 588.3249, 412.2912, and 297.1989) and the corresponding satellite ions, which were produced via ammonia or water loss (m/z 571.2985, 395.2657, 279.1820, and 261.1717) dominated the spectrum. Additionally, the ions generated by the cleavage of the glycosidic acid and/or the ester bond established the sugar and the lipid acids as glucuronic acid and hexanoic acid, respectively. The presence of ions at m/z 18 u higher (m/z 156.1035 and 138.0866) than the diagnostic ions that are typically generated from the Choi residue (m/z 140 and 122) indicated the dihydroxylation of the indole ring in this amino acid and were key fragments for the detection of other aeruginosin congeners.

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