Mass-spectrometry-directed analysis and purification of pyrrolizidine alkaloid cis/trans isomers in Gynura japonica.
Pyrrolizidine alkaloids are highly hepatotoxic natural chemicals that produce irreversible chronic and acute hepatotoxic effects on human beings. Purification of large amounts of pyrrolizidine alkaloids is necessary for toxicity studies. In this study, an efficient method for targeted analysis and purification of pyrrolizidine alkaloid cis/trans isomers from herbal materials was developed for the first time. Targeted analysis of the hepatotoxic pyrrolizidine alkaloids was performed by liquid chromatography with tandem mass spectrometry (precursor ion scan and daughter ion scan), and the purification of pyrrolizidine alkaloids was achieved with a mass-directed auto purification system. The extraction and preparative liquid chromatography conditions were optimized. The developed method was applied to analysis of Gynura japonica (Thunb.) Juel., a herbal medicine traditionally used for detumescence and relieving pain but is potentially hepatotoxic as it contains pyrrolizidine alkaloids. Twelve pyrrolizidine alkaloids (six cis/trans isomer pairs) were identified with reference compounds or characterized by liquid chromatography with tandem mass spectrometry, and five individual pyrrolizidine alkaloids, including (E)-seneciphylline, seneciphylline, integerrimine, senecionine, and seneciphyllinine, were prepared from G. japonica roots with high efficiency. The results of this work provide a new technique for the preparation of large amounts of pyrrolizidine alkaloid reference substances, which will also benefit toxicological studies of pyrrolizidine alkaloids and treatments for pyrrolizidine alkaloid-induced toxicity.
The Ministry of Education (MOE) Key Laboratory for Standardization of Chinese Medicines and the State Administration of TCM (SATCM) Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
Lianxiang
L
Fang
Aizhen
A
Xiong
Xiao
X
Yang
Wenzhi
W
Cheng
Li
L
Yang
Zhengtao
Z
Wang
D019659:Asteraceae / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D007536:Isomerism; D013058:Mass Spectrometry / Q000379:methods*; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D011763:Pyrrolizidine Alkaloids / Q000737:chemistry* / Q000302:isolation & purification
D010936:Plant Extracts; D011763:Pyrrolizidine Alkaloids
Auto purification systems; Gynura japonica; Isomers; Pyrrolizidine alkaloids; mass spectrometry