Abstract

Symposium Sessions

Day 1, June 10（Mon.）　16:25-16:40　Room A (Convention Hall 300)

Recently, we have found that inexplicable ions such as [M - H]+ are observed in matrix-assisted laser desorption/ionization mass spectrometry of some alkaloids. We studied [M - H]+ ion abundance of alkaloids. The [M - H]+ ion is more intense when a cyclic tertiary amine with single bonds is present in the molecule, and when a methine or methylene group structure is present next to the cyclic tertiary amine. The relative abundance analysis of the [M - H]+ ions were useful to characterize the structures of alkaloids in MALDI-MS.
We studied matrix effects on the generation of [M - H]+ ion of alkaloids. When multiple matrices with different chemical properties are measured separately, the progression of the dehydrogenation reaction in the alkaloids changes. Therefore, the matrix can be considered as an indicator of the dehydrogenation reaction.
Purine alkaloids include adenine, guanine, adenosine, guanosine, and other nucleic acid-related compounds, xanthines. 5-Nitrosalicylic acid (NSA) was useful to study purine alkaloids in MALDI-MS because the [M - H]+ ions generated in NSA-MALDI MS of some purine compounds although those never generated in other matrix-MALDI-MS. We will explain the relationship between the dehydrogenation reaction and the structure of purine alkaloids based on MALDI-MS analysis.

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