Oligosaccharide sequences in Quillaja saponins by electrospray ionization ion trap multiple-stage mass spectrometry.
Ten different samples with 13 previously identified saponin structures from Quillaja saponaria Molina were investigated by electrospray ionization ion trap multiple-stage mass spectrometry (ESI-ITMS(n)) in positive and negative ion modes. Both positive and negative ion mode MS(1)-MS(4) spectra were analyzed, showing that structural information on the two oligosaccharide parts in the saponin can be obtained from positive ion mode spectra whereas negative ion mode spectra mainly gave information on one of the oligosaccharide parts. Analysis of MS(1)-MS(4) spectra identified useful key fragment ions important for the structural elucidation of Quillaja saponins. A flowchart involving a stepwise procedure based on key fragments from MS(1)-MS(3) spectra was constructed for the identification of structural elements in the saponin. Peak intensity ratios in MS(3) spectra were found to be correlated with structural features of the investigated saponins and are therefore of value for the identification of terminal monosaccharide residues.
Broberg
Susanna
S
Department of Chemistry, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden.
Nord
Lars I
LI
Kenne
Lennart
L
D015394:Molecular Structure; D009844:Oligosaccharides / Q000032:analysis* / Q000737:chemistry; D024301:Plant Bark / Q000737:chemistry; D031990:Quillaja / Q000737:chemistry*; D012503:Saponins / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D014197:Trees / Q000737:chemistry
D009844:Oligosaccharides; D012503:Saponins