FIGURE 2.

Structural elucidation of 2,3-DHB3X by LC-MS. The molecular structure was determined by NMR spectroscopy (supplemental Fig. S3) and confirmed by LC-MS. A, LC-electrospray ionization-MS analysis of the peak representing 2,3-DHB3X. LC-electrospray ionization-MS analysis in negative ion mode revealed an ion of m/z 285.061 as [M-H], suggesting a molecular formula of M = C₁₂H₁₄O₈. B and C, the insource fragment at m/z 153.018 and subsequent CID experiments of the parent ion (285.06) (B) and the daughter ion (153.02) (C) showed a neutral loss of a pentose moiety indicating that 2,3-DHBA is linked to the pentose xylose. D, structure of 2,3-DHB3X.