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Structural studies of polyhydroxybis(tetrahydrofuran)acetogenins from Annona squamosa using the combination of chemical derivatization and precursor‐ion scanning mass spectrometry
Author(s) -
Hirayama Kazuo,
Akashi Satoko,
Yuji Reiko,
Niitsu Uno,
Fujimoto Yoshinori
Publication year - 1993
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210281225
Subject(s) - acetogenin , chemistry , derivatization , tetrahydrofuran , mass spectrometry , fast atom bombardment , fragmentation (computing) , derivative (finance) , mass spectrum , ion , stereochemistry , annonaceae , chromatography , organic chemistry , medicine , solvent , computer science , financial economics , economics , operating system , traditional medicine
Abstract The structure of squamocin polyhydroxybis(tetrahydrofuran)acetogenin from Annona squamosa L., was characterized by a combination of the chemical derivatization and precursor‐ion scanning mass spectrometry. The lactone part of squamocin was modified with N , N ‐dimethylethylenediamine in the vapour phase to afford a strong positive charge at one end of the skeleton. The derivative was ionized by fast atom bombardment (FAB), and the product ion spectrum from [M + H] + and the precursor ion spectrum from the m / z 72 ion [CH 2 CHN + H(CH 3 ) 2 ] generated by low‐energy collision were acquired. The structure of the derivative could be characterized by the precursor‐ion spetrum from the m / z 72 ion, but little structural information could be obtained from the production spectrum from [M + H] + of the derivative. By the attachment of a tertiary amino group to one end of the skeleton, charge‐remote fragmentation was facilitated and abundant and unique fragment ions were observed in the precursor‐ion spectrum. Structural characterization of six other isolated compounds was also carried out, and two novel compounds were found by this technique. A similar derivatization was applied in the peptide leu‐enkephalin, and full sequencing from the C ‐terminus using precursor‐ion scanning from m / z 72 could be achieved.