The glucosyl ester (2b), the galactosyl ester (3b), the xylosyl ester (4b) and the arabinosyl ester (5b) of gibberellin A3 (GA3) as well as the glucosyl ester (7b) and the xylosyl ester (8b) of isoGA3 were synthesized and their structures confirmed especially by 1H nuclear magnetic resonance. In order to identify such conjugates in nature, the glycosyl esters 2b, 3b, 4b, 5b, 7b and 8b were subjected to mass spectrometry analysis using fast atom bombardment and electrospray ionization techniques. The spectra obtained from both negative and positive ions were compared and interpreted on the basis of tandem mass spectrometry experiments. The differences between the fragmentation of GA3 glycosyl ester and that of isoGA3 glucosyl ester are discussed. Diagnostic ions were evaluated, which should be useful for the identification of these conjugates by liquid chromatography/mass spectrometry.
赤霉素A3(
GA3)的
葡糖基酯(2b)、半
乳糖基酯(3b)、
木糖基酯(4b)和
阿拉伯糖基酯(5b)以及
赤霉素A3(
GA3)的
葡糖基酯(7b)和
木糖基酯(8b)合成了iso
GA3,并特别通过1H核磁共振证实了其结构。为了鉴定自然界中的此类缀合物,使用快原子轰击和电喷雾电离技术对糖基酯2b、3b、4b、5b、7b和8b进行质谱分析。根据串联质谱实验对从负离子和正离子获得的光谱进行比较和解释。讨论了
GA3糖基酯和iso
GA3糖基酯断裂的差异。对诊断离子进行了评估,这对于通过
液相色谱/质谱法鉴定这些缀合物应该有用。