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Structure elucidation of new acetylated saponins, Lessoniosides A, B, C, D, and E, and non-acetylated saponins, Lessoniosides F and G, from the viscera of the sea cucumber Holothuria lessoni.

Bahrami Y, Franco CM - Mar Drugs (2015)

Bottom Line: The presence of the O-acetyl group was confirmed by observing the mass transition of 60 u corresponding to the loss of a molecule of acetic acid.As a result, and in conjunction with existing literature, we characterized the structure of five new acetylated saponins, Lessoniosides A-E, along with two non-acetylated saponins Lessoniosides F and G at m/z 1477.7, which are promising candidates for future drug development.The presented strategy allows a rapid, reliable and complete analysis of native saponins.

View Article: PubMed Central - PubMed

Affiliation: Medical Biotechnology, Flinders Medical Science and Technology, School of Medicine, Flinders University, Adelaide SA 5042, Australia. ybahrami@mbrc.ac.ir.

ABSTRACT
Sea cucumbers produce numerous compounds with a wide range of chemical structural diversity. Among these, saponins are the most diverse and include sulfated, non-sulfated, acetylated and methylated congeners with different aglycone and sugar moieties. In this study, MALDI and ESI tandem mass spectrometry, in the positive ion mode, were used to elucidate the structure of new saponins extracted from the viscera of H. lessoni. Fragmentation of the aglycone provided structural information on the presence of the acetyl group. The presence of the O-acetyl group was confirmed by observing the mass transition of 60 u corresponding to the loss of a molecule of acetic acid. Ion fingerprints from the glycosidic cleavage provided information on the mass of the aglycone (core), and the sequence and type of monosaccharides that constitute the sugar moiety. The tandem mass spectra of the saponin precursor ions [M + Na]+ provided a wealth of detailed structural information on the glycosidic bond cleavages. As a result, and in conjunction with existing literature, we characterized the structure of five new acetylated saponins, Lessoniosides A-E, along with two non-acetylated saponins Lessoniosides F and G at m/z 1477.7, which are promising candidates for future drug development. The presented strategy allows a rapid, reliable and complete analysis of native saponins.

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Related in: MedlinePlus

The schematic diagram of the proposed isomeric structures of the ion at m/z 1477.7. This figure indicates the comprehensive feasible fragmentation pathways of the isomeric acetylated, Lessoniosides (A–E), and non-acetylated, Lessoniosides (F–G), triterpene glycosides generated from the ion at m/z 1477.7.
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marinedrugs-13-00597-f003: The schematic diagram of the proposed isomeric structures of the ion at m/z 1477.7. This figure indicates the comprehensive feasible fragmentation pathways of the isomeric acetylated, Lessoniosides (A–E), and non-acetylated, Lessoniosides (F–G), triterpene glycosides generated from the ion at m/z 1477.7.

Mentions: CID activates three feasible independent fragmentation pathways of cationized parent ions shown in full and dotted arrows. First, as described in Figure 2, the consecutive losses of the deacetylated aglycone, acetic acid (AcOH), 3-O-methyl-d-glucose (MeGlc), d-quinovose (Qui), d-xylose (Xyl), MeGlc and Xyl residues (blue arrows) followed by d-glucose (Glc) yielded ion fragments at m/z 1007.5, 947.5, 771.4, 625.2, 493.1, 317.1 and 185.0 (Figure 3a), respectively, in one of the new isomers for which we propose the name Lessonioside A. The loss of aglycone (Agl) generated the ion at m/z 947, corresponding to the complete sugar moiety. The ion at m/z 493.1 corresponds to the diagnostic sugar reside [MeGlc-Glc-Xyl + Na]+. Further, the sequential losses of Glc and Xyl units from this key diagnostic peak (m/z 493.1) generated ions at m/z 331.1 and 199.0 (Figure 3b).


Structure elucidation of new acetylated saponins, Lessoniosides A, B, C, D, and E, and non-acetylated saponins, Lessoniosides F and G, from the viscera of the sea cucumber Holothuria lessoni.

Bahrami Y, Franco CM - Mar Drugs (2015)

The schematic diagram of the proposed isomeric structures of the ion at m/z 1477.7. This figure indicates the comprehensive feasible fragmentation pathways of the isomeric acetylated, Lessoniosides (A–E), and non-acetylated, Lessoniosides (F–G), triterpene glycosides generated from the ion at m/z 1477.7.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4306954&req=5

marinedrugs-13-00597-f003: The schematic diagram of the proposed isomeric structures of the ion at m/z 1477.7. This figure indicates the comprehensive feasible fragmentation pathways of the isomeric acetylated, Lessoniosides (A–E), and non-acetylated, Lessoniosides (F–G), triterpene glycosides generated from the ion at m/z 1477.7.
Mentions: CID activates three feasible independent fragmentation pathways of cationized parent ions shown in full and dotted arrows. First, as described in Figure 2, the consecutive losses of the deacetylated aglycone, acetic acid (AcOH), 3-O-methyl-d-glucose (MeGlc), d-quinovose (Qui), d-xylose (Xyl), MeGlc and Xyl residues (blue arrows) followed by d-glucose (Glc) yielded ion fragments at m/z 1007.5, 947.5, 771.4, 625.2, 493.1, 317.1 and 185.0 (Figure 3a), respectively, in one of the new isomers for which we propose the name Lessonioside A. The loss of aglycone (Agl) generated the ion at m/z 947, corresponding to the complete sugar moiety. The ion at m/z 493.1 corresponds to the diagnostic sugar reside [MeGlc-Glc-Xyl + Na]+. Further, the sequential losses of Glc and Xyl units from this key diagnostic peak (m/z 493.1) generated ions at m/z 331.1 and 199.0 (Figure 3b).

Bottom Line: The presence of the O-acetyl group was confirmed by observing the mass transition of 60 u corresponding to the loss of a molecule of acetic acid.As a result, and in conjunction with existing literature, we characterized the structure of five new acetylated saponins, Lessoniosides A-E, along with two non-acetylated saponins Lessoniosides F and G at m/z 1477.7, which are promising candidates for future drug development.The presented strategy allows a rapid, reliable and complete analysis of native saponins.

View Article: PubMed Central - PubMed

Affiliation: Medical Biotechnology, Flinders Medical Science and Technology, School of Medicine, Flinders University, Adelaide SA 5042, Australia. ybahrami@mbrc.ac.ir.

ABSTRACT
Sea cucumbers produce numerous compounds with a wide range of chemical structural diversity. Among these, saponins are the most diverse and include sulfated, non-sulfated, acetylated and methylated congeners with different aglycone and sugar moieties. In this study, MALDI and ESI tandem mass spectrometry, in the positive ion mode, were used to elucidate the structure of new saponins extracted from the viscera of H. lessoni. Fragmentation of the aglycone provided structural information on the presence of the acetyl group. The presence of the O-acetyl group was confirmed by observing the mass transition of 60 u corresponding to the loss of a molecule of acetic acid. Ion fingerprints from the glycosidic cleavage provided information on the mass of the aglycone (core), and the sequence and type of monosaccharides that constitute the sugar moiety. The tandem mass spectra of the saponin precursor ions [M + Na]+ provided a wealth of detailed structural information on the glycosidic bond cleavages. As a result, and in conjunction with existing literature, we characterized the structure of five new acetylated saponins, Lessoniosides A-E, along with two non-acetylated saponins Lessoniosides F and G at m/z 1477.7, which are promising candidates for future drug development. The presented strategy allows a rapid, reliable and complete analysis of native saponins.

Show MeSH
Related in: MedlinePlus