Liquid Chromatography/Mass Spectrometry with Atmospheric Pressure Chemical Ionization of Free Brassinosteroids

✍ Scribed by Keiji Gamoh; Hiroyuki Abe; Katsuya Shimada; Suguru Takatsuto

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 408 KB
• Volume: 10
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(19960610)10:8<903::aid-rcm564>3.0.co;2-2

✦ Synopsis

Liquid chromatography/mass spectrometry (LC/MS) with atmospheric pressure chemical ionization has been successfully applied to the simultaneous analysis of free brassinosteroids (polyhydroxylated steroids that serve as plant growth regulators) as their naphthaleneboronates. Of a range of analytical conditions that were tested, optimum results were obtained by the use of reversed-phase high-performance liquid chromatography using a mixture of acetonitrile and water. The positive-ion spectra of naphthaleneboronates of brassinosteroids showed pseudo-molecular ions, m+H]+, and fragment ions corresponding to the losse~ of hydroxyl groups of the steroidal nucleus. The [M+HJ+ ion was the most abundant for brassinolide and the [M+H -H , O ] ' ions were the mast abundant for castasterone, teasterone and typhasterol. Full-scan mass spectra were readily obtained from 400 ng of free brassinosteroids, while a limit of detection of 2 ng (signal-to-noise ratio 3) was attained in the selected-ion monitoring mode. The application of LCMS to the study of brassinosteroids in a plant material is demonstrated by the analysis of seeds of Cannubis s&.va L.