Analysis of natural brassinosteroids by gas chromatography and gas chromatography—mass spectrometry

Abstract

The microanalysis of various kinds of brassinosteroids as their bismethaneboronate derivatives was investigated by gas chromatography (GC) and gas chromatography—mass spectrometry (GC—MS). GC analysis using a glass capillary column indicated that the brassinosteroid methaneboronates can be detected at the nanogram level. The fragmentation patterns of the bismethaneboronate derivatives of brassinosteroids were examined using GC—EI (electron impact)-MS and GC—CI (chemical ionization)-MS systems. Selected ion monitoring using the GC—CI-MS system was applied to the analysis of natural brassinosteroids in several plants. Brassinolide, castasterone, 28-norbrassinolide, brassinone, 24-ethylbrassinone and dolichosterone were identified in the immature needs and sheaths of chinese cabbage, Brassica campestris L. var. pekinensis, the leaves of green tea, Thea sinensis, the insect galls of the chesnut tree, Castanea crenata L. Sieb. et Zucc., the insect galls and the leaves of Distylium racemosum Sieb. et Zucc. and the whole plant except the roots of the rice, Oryza sativa L. cv. Arborio J1. The results demonstrate that this microanalysis is useful for the screening of brassinosteroids in plants.