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Lappaconitine (LAP), a non-addictive potent analgesic drug, is broadly used to treat cancer and postoperative pain in many countries, and it also has antibiotic activity against Pseudomonas aeruginosa and Salmonella Typhi. Despite its widespread usage and potential for expanded use, its metabolism was poorly investigated. In this work, the metabolic fate of LAP in liver microsomes of the rat and human was compared, and after oral administration, the metabolites in the rat were investigated using ultra high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q/TOF-MS). As a result, a total of 51 metabolites were identified, including 48 metabolites that were reported here for the first time. Based on accurate MS/MS spectra and the known structure of LAP, the metabolites structures and their fragment ions were readily characterized. The biotransformations of LAP in vitro and in vivo were shown to involve hydroxylation, N-deacetylation, O-demethylation, N-deethylation, and hydrolysis. Furthermore, the results indicated a quantitative species difference in the metabolites for LAP between the rat and human. However, 16-DMLAP, DAL and 5'-OH-DAL were the main in vitro and in vivo metabolites. This work provides the LAP metabolite profiles in rat and human, which will help better understand the pharmacological and toxicological activities of LAP., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The mesaconitine and its major metabolites in the rat urine were identified by liquid chromatography and electrospray ionization tandem mass spectrometry. The rat urine was collected for consecutive 24 hours from the rat following intragastric infusion of mesaconitine, subsequently which were enriched and purified using solid phase extraction. The metabolites of mesaconitine in the rat urine were analyzed by the liquid chromatography and electrospray ionization tandem mass spectrometry. It is shown that the parent drug mesaconitine and its metabolites were found in the rat urine, such as hypo-mesaconitine glucuronic acid conjugate, 10-hydroxy-mesaconitine, 1-O-demethyl mesaconitine, deoxy-mesaconitine and hypo-mesaconitine. Among the five of metabolites, the hypo-mesaconitine glucuronic acid conjugate (m/z 766) was first discovered as the aconitine in rats phase II metabolites, which revealed a new way of mesaconitine metabolism in rats.

A novel analytical method was developed and validated for the rapid and simultaneous analysis of five toxic alkaloids: Brucine, Strychnine, Ephedrine, Aconitine and Colchicine, in blood and urine using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry in the multiple reaction monitoring (HPLC-ESI-MRM) mode. The linear range was 0.05-50.0 ng mL(-1) for Brucine, 0.1-50.0 ng mL(-1) for Strychnine and Ephedrine, 0.01-10.0 ng mL(-1) for Aconitine and Colchicine. The limits of quantification for Brucine, Strychnine, Ephedrine, Aconitine and Colchicine were found to be 0.03, 0.05, 0.20, 0.05, 0.01 ng mL(-1), respectively. The average extraction recoveries in urine ranged from 96.0 to 114.0% and in whole blood were 94.0 to 113.0%. The intra-day and inter-day RSDs were less than 8.3 and 10.6%, respectively. The five alkaloids could be well separated within 7 min in a single run. The established method should be suitable for the determination of trace alkaloids in body fluids.

Poisoning from aconite occurs worldwide as a result of misuse of the potent plant. Laboratory investigation into suspected intoxication cases is challenging because the content of toxic aconitum alkaloids varies depending on the plant source, market processing, dosing protocol, hydrolytic degradation, and metabolic transformation. Using a triple-quadrupole tandem mass spectrometer, a group screening method was developed based on the mass-fragmentographic scheme of common aconitum alkaloids. The precursor-ion scans of m/z 105 and 135 permitted selective profiling of 14-O-benzoyl-norditerpenoids and the 14-O-anisoyl-norditerpenoids, respectively. Gradient reversed-phase liquid chromatography minimized coelution of isobaric compounds. The screening protocol was applied to a clinical investigation of suspected herbal poisoning. In total, 15 urine samples were thus screened positive for aconitum alkaloid over 5 years. The diagnoses of aconite poisoning in 11 patients were firmly established based on the known prescription history and the positive urine finding. In four patients, without aconitum herbs being listed in the herbal prescriptions, contamination of the herbal remedies by aconite was suspected to be the hidden cause of their acute poisoning. Yunaconitne, a highly toxic aconitum alkaloid, was thus identified in human urine for the first time. The group screening method of aconitum alkaloids in urine is an important diagnostic aid for acute poisoning by aconites of an unclear origin.