A study ofaconitum alkaloids from aconite roots inAconitum carmichaeli Debx using matrix-assisted laser desorption/ionization mass spectrometry

Abstract

In the present paper a study of C 19 -diterpene type of aconitum alkaloids, extracted from aconite roots in Aconitum carmichaeli Debx has been made using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOFMS). The results demonstrated that the aconitum alkaloids from aconite roots can be determined simultaneously by this method, which was found to be superior to other analytical methods with regard to speed and sensitivity. Fourteen known aconitum alkaloids, including aconitines, benzoylaconitines and lipoaconitines, were assigned in the methanol extract and three compounds not reported before have been targeted separation. The evaluation of the efficiency of different extractions has been studied. These results suggested that the differences of the polarity and basicity of aconitine, and benzoylaconitines and lipoaconitines result from the C-8 constituent groups that are easily lost under MALDI. #

Diterpenoid alkaloids

“…The characteristic ion peak at [M + HÀ OR/C-8] + of the lipoalkaloids in the MS 2 spectra is usually derived by the loss of the long-chain fatty acid ester at the C-8 position. [272][273][274]277,278 Except for this point, the other fragmentation patterns in their MS n spectra are similar to those of aconitine-type alkaloids.…”

“…12 of diterpenoid alkaloids in blood and urine, 271 various softionization techniques and their combinations with other techniques have been extensively applied to determine diterpenoid alkaloids in mixed samples (including extracts and metabolites). [243][244][245][272][273][274][275][276][277][278][279][280][281][282][283][284][285][286][287][288][289] This technique has been found to be superior to other analytical methods with regard to sample amount, speed, sensitivity, and convenience.…”

“…Liu et al have extensively investigated the analysis of diterpenoid alkaloids, including pure alkaloid or mixed samples (especially for the alkaloids from ''chuan wu'', ''fu zi'', and ''cao wu'') by ESI-MS n . [243][244][245]272,[274][275][276][277][278][279]283,284 The most important fragmentation features in the ESI-MS n of this kind of diterpenoid alkaloids are that the characteristic ion peaks come from the cleavage of substituents (such as OH, OMe, OAc, OBz, NMe, NEt); in a very few cases ring fragmentation is involved.…”

Investigations of diterpene alkaloids isolated from Aconitum anthora L. and A. moldavicum L., and of aconitine-derived lipo-alkaloids

“…Structures of the already known LAs along with their parent DDAs and the structures of by-products of semisynthetic reactions were also summarized in our before mentioned paper. 19 Many papers on the isolation of LAs from plant material [21][22][23][24][25] reported these compounds to be complex mixtures, and stated that direct chromatographic isolation of the individual components is extremely difficult because of their very similar physico-chemical properties and chromatographic behaviour. Therefore, at the beginning of the research on the topic indirect degradation (methanolic 17 , alkaline 24,25 ) methods were elaborated, while later on and along with the development of highly sensitive analytical methods electrospray ionization mass spectrometry (ESI-MS n ) 20,22,[26][27][28] , matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS n ) 23,29,30 , and atmosphericpressure chemical ionization mass spectrometry (APCI-MS n ) 31 were and are the main methods used for unambiguous compound identification and structure elucidation.…”