Studies on the stability of diester-diterpenoid alkaloids from the genus Aconitum L. by high performance liquid chromatography combined with electrospray ionisation tandem mass spectrometry (HPLC/ESI/MSn).
The stability of diester-diterpenoid alkaloids (DDA) from plants of the genus Aconitum L. has been studied in different solvents and pH buffers. The HPLC/ESIMS method for analysing the concentration of DDA was established and DDA's decomposition products were elucidated by HPLC/ESI-MS/MS(n). In different solvents, e.g. dichloromethane, ether, methanol and distilled water, the decomposition pathways of DDA are quite different and their difference in stabilities depends on the difference of their structures, in which substituents at the N atom and substituents at C-3 are different. The pyrolytic products of DDA, such as deacetoxy aconitine-type alkaloids, have been observed in the above solvents, whereas 8-methoxy-14-benzoyl aconitine-type alkaloids have been obtained only in methanol. Furthermore, the experimental results demonstrate that the stability of DDA depends on pH values of the buffer. Aconine as hydrolysate has been only found in pH 10.0 buffer, and the other hydrolysates and the pyrolyzates of DDA, such as benzoylaconine and deacetoxy aconitine, have been observed in all pH aqueous solutions. The decomposition pathways of DDA in buffers are related to the substituent on the C-3 position. The decomposition pathway of aconitine is similar to that of mesaconitine, but different from that of hypaconitine.
Yue
Hao
H
Changchun Center of Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, People's Republic of China.
Pi
Zi-Feng
ZF
Li
Hui-Lin
HL
Song
Feng-Rui
FR
Liu
Zhi-Qiang
ZQ
Liu
Shu-Ying
SY
D031841:Aconitum / Q000737:chemistry*; D000470:Alkaloids / Q000032:analysis* / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004986:Ether / Q000737:chemistry; D008752:Methylene Chloride / Q000737:chemistry; D015394:Molecular Structure; D012997:Solvents / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014867:Water / Q000737:chemistry
D000470:Alkaloids; D012997:Solvents; D014867:Water; D004986:Ether; D008752:Methylene Chloride