Simultaneous analysis of aconitine, mesaconitine, hypaconitine, and jesaconitine in whole blood by LC-MS-MS using a new polymer column

Simultaneous quantification of nine aconitum alkaloids in Aconiti Lateralis Radix Praeparata and related products using UHPLC-QQQ-MS/MS

Aconiti Lateralis Radix Praeparata (Fuzi) is obtained from processed daughter roots of Aconitum carmichaeli, a toxic plant with a high medical value well known in Chinese medicine. In addition to the known toxic alkaloids (aconitine, mesaconitine, and hypaconitine) and bioactive alkaloids (benzoylaconine, benzoylmesaconine, and benzoylhypaconine), three rarely found alkaloids have been previously reported in Fuzi, i.e., yunaconitine, 8-deacetyl-yunaconitine, and crassicauline A, and they were reported in recent years to cause potential risk to patients who took Fuzi or related products. To better control the quality of this herb and its related products and ensure safe use, developing a method to simultaneously determine these 9 alkaloids is important. In this research, sensitive and accurate ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry method was established and used to examine 51 Fuzi and 27 Fuzi-containing products. Unexpectedly, 8-deacetyl-yunaconitine was detected in 17 Fuzi samples (33.3%) and 3 Fuzi-containing products (11.1%); yunaconitine in 10 Fuzi samples (19.6%) and 10 Fuzi-containing products (37.0%); and crassicauline A in 3 Fuzi samples (5.8%). Industry and clinics should be aware of the unusually high detection rate of these three toxic alkaloids in the Fuzi herb and its related products and take the necessary precautions to protect patients from any potential risk.

A fragmentation study on four C19-diterpenoid alkaloids by electrospray ionization ion-trap time-of-flight tandem mass spectrometry

High-resolution electrospray ionization ion-trap time-of-flight tandem mass spectrometry (HR-ESI-IT-TOF-MS(n)) in positive-ion mode was used to determine the accurate masses and fragmentation pathways of four C(19)-diterpenoid alkaloids, aconitine (1), yunnaconitine (2), crassicauline A (3), and benzoylmesaconine (4). The [M+H](+) ions of compounds 1-4 were readily observed in conventional single-stage mass spectrometry. Based on the MS(1-6) analyses, detailed fragmentation rules of the four compounds were proposed. The neutral losses of AcOH, MeOH, H(2)O, CO, C(2)H(4), PhCOOH and p-OMePhCOOH segments were the characteristic eliminations from the precursor ions due to the presence of acetyl, methoxyl, hydroxyl, N-ethyl, benzoyl and p-methoxyl-benzoyl units in the structures. Benefited from the high resolution of the mass analyzer, the loss of 28 Da corresponding to CO or CH(4) segment in product ions was unambiguously distinguished. The losing sequence of the main substituent groups was summarized as: C(8)-acetyl>C(16)-methotyl>C(15)-hydroxyl>C(6)-methoxyl>C(1)-methoxyl/C(3)-hydroxyl>C(18)-methoxyl>>C(13)-hydroxyl. The sequential loss of (16)-methoxyl moiety and CO (generating from enol-ketone tautomerism) groups could be recognized as the characteristic eliminations for the compounds with C(16)-methoxyl and C(15)-hydroxyl groups simultaneously. The application of HR-ESI-IT-TOF-MS(n) technique to investigate the fragmentation of C(19)-diterpenoid alkaloids provided useful information to understand their fragmentation behaviors.