Qualitative and quantitative analysis of lipo-alkaloids and fatty acids in Aconitum carmichaelii using LC-MS and GC-MS.

INTRODUCTION: Lipo-alkaloid (LA) is a kind of C19 -norditerpenoid alkaloid in Aconitum species, which usually contains an aconitane skeleton and one or two fatty acid residues.

OBJECTIVE: To qualify and quantify the fatty acids and lipo-alkaloids in Aconitum carmichaelii.

METHODOLOGY: An ultra-high performance liquid chromatography-triple quadrupole-mass spectrometry (UHPLC-QQQ-MS) method was established to quantify LAs, while the free fatty acids were identified by gas chromatography-mass spectrometry (GC-MS) and ultra-high performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UHPLC-Q-TOF-MS).

RESULTS: Six major LAs (1-6) containing linoleic, palmitic, and oleic acid residues as side chains were quantified. Eighteen fatty acids were determined by GC-MS, and 15 were detected as the side chains of LAs. The LAs containing these 15 fatty acid residues accounted for about a third of the total identified LAs. Moreover, the contents of linoleic, palmitic, and oleic acids were highest. In addition, 12 oxygenated fatty acids were also identified by UHPLC-Q-TOF-MS for the first time.

CONCLUSION: The positive correlation between free fatty acids and LAs in A. carmichaelii indicated that the types and contents of LAs were influenced by free fatty acids.