邦産キノコの成分研究(第6報) : イボテン酸関連化合物のマススぺクトルその1 : 3-Hydroxyisoxazole類のフラグメンテーション

抄録

The mass spectra of ibotenic acid(I), the pyro compound (5 -aminomethyl-3-hydroxyisoxazole)(III), and several 3-hydroxyisoxazoles are reported and discussed. Each fragmentation pathways are substantiated by exact mass measurements and deuterium labeling. The common features in 3-hydroxyisoxazoles in general are the prominent molecular ions and diagnostic fragment ions arising from the cleavage of the O-N and C(4)-C(5) bonds and/or from the eliminations of functional groups on the side chains and subsequent ring cracking. Unexpectedly, however, spectra of I and III, exhibited the formations of i₃), i₄, i₇), and i₉) ions, having no correlation with the fragments in common 3-hydroxyisoxazoles. The fragmentation mechanisms of these ions are also discussed.