反射模式与线性模式MALDI-TOF MS联合分析荔枝果核缩合单宁

Characterization of Condensed Tannins from Litchi Seed by Reflectron Modes and Linear Modes of MALDI-TOF MS

利用不同模式的基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)分析荔枝果核缩合单宁.在反射模式(Reflectron modes)下,加速电压20.0 kV,反射电压23.0 kV,延时取出电压16.32 kV,聚焦电压9.45 kV,获得缩合单宁的准确结构单元组成和连接方式信息,其为三聚体至十八聚体组成的A型原花青定多聚物.在线性模式(Linear modes)下,加速电压20.0 kV,延时取出电压16.25 kV,聚焦电压10.0 kV,检测到十九聚体至二十七聚体的缩合单宁信号,其更全面获取缩合单宁聚合度的分布信息.综合两种模式,荔枝果核缩合单宁是由三聚体至二十七聚体分布的A型原花青定多聚物.探讨了一种联合反射模式与线性模式对植物单宁结构准确分析的基质辅助激光解吸电离飞行时间质谱方法.

Condensed tannins from litchi seed were analyzed using reflectron modes and linear modes of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry（MALDI-TOF MS）.The reflectron modes（accelerating voltage,20.0 kV;reflectron voltage,23.0 kV;delayed extraction voltage,16.32 kV;lens voltage,9.45 kV） spectra obtained clear information on basic unit,interflavan linkage and polymerization degree extended from 3-mers to 18-mers.The linear modes（accelerating voltage,20.0 kV;delayed extraction voltage,16.25 kV;lens voltage,10.0 kV） spectra further expanded the detectable polymers up to 27-mers.Litchi seed condensed tannins were A-type procyanidins polymer with as high as 27-mers.In the present study,reflectron modes coupled with linear modes was discussed as a potential method of MALDI-TOF MS in characterization of condensed tannins.