Fragmentation investigation of brassinosteroid compounds by ion trap and quadrupole time‐of‐flight mass spectrometry

Abstract

The fragmentation mechanisms of three types of brassinosteroids (BRs), 23,24-tris-epicastasterone, epicastasterone, tris-epicastasterone, 24-epibrassinolide and 6-deoxo-24-epicastasterone, have been extensively investigated by tandem mass spectrometry (MS(n), n = 1, 2, 3, 4, 5) with the assistance of high mass accuracy quadrupole time-of-flight mass spectrometry (QToF MS). The electrospray ionization (ESI) mass spectrometric fragmentation pathways of these five BRs were comprehensively elucidated for the first time. Cleavages of side chains, neutral losses of water or other molecules and opening of a ring induce the main fragmentation patterns. The results from the present study can potentially afford important guidance for the structural elucidation of different BRs and provide some fundamental data for metabolomic analysis of BRs.

Antifungal activity of secondary plant metabolites from potatoes (Solanum tuberosum L.): Glycoalkaloids and phenolic acids show synergistic effects

“…Therefore, the relative amount of each compound can only be compared separately between strains. In all strains considered in this study, the most abundant sterols were ergosterol and compound E, the mass spectrum of which showed fragments at m/z 445, 427 and 409, which has been observed in 24-epibrassinolide (Huo and Liu 2010). Therefore, compound E might be a brassinosteroid or a derivative.…”

Tandem mass spectrometric characterization of acetylated polyhydroxy hellebosaponins, the principal steroid saponins inHelleborus nigerL. roots#

“…A hint for the nature of this ion was given by the peak m/z 501, appearing right next to m/z 441. As already known for other steroids, some tend to readily cleave H 2 O concluding m/z 501 to be the [(aglycone–H 2 O) + H] + . They dehydrate in a special way: Often, water eliminates by introducing a double bond into the carbon (ring) structure as assumed for the dehydration of the ion triplets m/z 441, 423 and 405 or m/z 287, 269 and 251.…”

Determination of Brassinolide Analogs by High-Performance Liquid Chromatography with Evaporative Light Scattering Detection

“…The quasi-molecular ion peaks varied according to the mass spectrometry conditions used. In the full scan spectrum of 24-epibrassinolide reported byHuo, Bai, and Liu (2010), the base peak at m=z 481 was the [MþH] þ ion, and the minor ions at m=z 503 and 519 were consistent with the [MþNa] þ and [MþK] þ ions.…”