Inhibition of the INa/K and the activation of peak INa contribute to the arrhythmogenic effects of aconitine and mesaconitine in guinea pigs.

Aconitine (ACO), a main active ingredient of Aconitum, is well-known for its cardiotoxicity. However, the mechanisms of toxic action of ACO remain unclear. In the current study, we investigated the cardiac effects of ACO and mesaconitine (MACO), a structurally related analog of ACO identified in Aconitum with undocumented cardiotoxicity in guinea pigs. We showed that intravenous administration of ACO or MACO (25 µg/kg) to guinea pigs caused various types of arrhythmias in electrocardiogram (ECG) recording, including ventricular premature beats (VPB), atrioventricular blockade (AVB), ventricular tachycardia (VT), and ventricular fibrillation (VF). MACO displayed more potent arrhythmogenic effect than ACO. We conducted whole-cell patch-clamp recording in isolated guinea pig ventricular myocytes, and observed that treatment with ACO (0.3, 3 µM) or MACO (0.1, 0.3 µM) depolarized the resting membrane potential (RMP) and reduced the action potential amplitude (APA) and durations (APDs) in a concentration-dependent manner. The ACO- and MACO-induced AP remodeling was largely abolished by an INa blocker tetrodotoxin (2 µM) and partly abolished by a specific Na+/K+ pump (NKP) blocker ouabain (0.1 µM). Furthermore, we observed that treatment with ACO or MACO attenuated NKP current (INa/K) and increased peak INa by accelerating the sodium channel activation with the EC50 of 8.36 ± 1.89 and 1.33 ± 0.16 µM, respectively. Incubation of ventricular myocytes with ACO or MACO concentration-dependently increased intracellular Na+ and Ca2+ concentrations. In conclusion, the current study demonstrates strong arrhythmogenic effects of ACO and MACO resulted from increasing the peak INa via accelerating sodium channel activation and inhibiting the INa/K. These results may help to improve our understanding of cardiotoxic mechanisms of ACO and MACO, and identify potential novel therapeutic targets for Aconitum poisoning.

Supramolecular structure, in vivo biological activities and molecular-docking-based potential cardiotoxic exploration of aconine hydrochloride monohydrate as a novel salt form.

Despite the high profile of aconine in WuTou injection, there has been no preparative technology or structural studies of its salt as the pharmaceutical product. The lack of any halide salt forms is surprising as aconine contains a tertiary nitrogen atom. In this work, aconine was prepared from the degradation of aconitine in Aconiti kusnezoffii radix (CaoWu). A green chemistry technique was applied to enrich the lipophilic-poor aconine. Reaction of aconine with hydrochloride acid resulted in protonation of the nitrogen atom and gave a novel salt form (C25H42NO9+·Cl-·H2O; aconine hydrochloride monohydrate, AHM), whose cation in the crystal structure was elucidated based on extensive spectroscopic and X-ray crystallographic analyses. The AHM crystal had a Z' = 3 structure with three independent cation-anion pairs, with profound conformational differences among the aconine cations. The central framework of each aconine cation was compared with that of previously reported aconitine, proving that protonation of the nitrogen atom induced the structure rearrangement. In the crystal of AHM, aconine cations, chloride anions and water molecules interacted through inter-species O-H...Cl and O-H...O hydrogen bonds; this complex hydrogen-bonding network stabilizes the supramolecular structure. The seriously disordered solvent molecules were treated using the PLATON SQUEEZE procedure [Spek (2015). Acta Cryst. C71, 9-18] and their atoms were therefore omitted from the refinement. Bioactivity studies indicated that AHM promoted in vitro proliferative activities of RAW264.7 cells. Molecular docking suggested AHM could target cardiotoxic protein through the hydrogen-bonding interactions. The structural confirmation of AHM offers a rational approach for improving the pharmaceutical technology of WuTou injection.

Neoline, an active ingredient of the processed aconite root in Goshajinkigan formulation, targets Nav1.7 to ameliorate mechanical hyperalgesia in diabetic mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Goshajinkigan (GJG), a traditional Japanese Kampo formula, has been shown to exhibit several pharmacological actions, including antinociceptive effects. Processed aconite root (PA), which is considered to be an active ingredient of GJG, has also been demonstrated to have an ameliorative effect on pain, such as diabetic peripheral neuropathic pain. We recently identified neoline as the active ingredient of both GJG and PA that is responsible for its effects against oxaliplatin-induced neuropathic pain in mice. AIM OF THE STUDY: In the present study, we investigated whether GJG, PA, and neoline could inhibit Nav1.7 voltage-gated sodium channel (VGSC) current and whether neoline could ameliorate mechanical hyperalgesia in diabetic mice. MATERIALS AND METHODS: To assess the electrophysiological properties of GJG extract formulation, powdered PA, and neoline on Nav1.7 VGSCs, whole-cell patch clamp recording was performed using human HEK293 cells expressing Nav1.7 VGSCs. In addition, the ameliorative effects of neoline on diabetic peripheral neuropathic pain were evaluated using the von Frey test in streptozotocin (STZ)-induced diabetic model mice. RESULTS: GJG extract formulation significantly inhibited Nav1.7 VGSC peak current. Powdered PA also inhibited Nav1.7 VGSC peak current. Like GJG and PA, neoline could inhibit Nav1.7 VGSC current. When diabetic mice were treated with neoline by intraperitoneal acute administration, the mechanical threshold was increased in diabetic mice, but not in non-diabetic mice, in a behavioral study. CONCLUSION: These results suggest that neoline might be a novel active ingredient of GJG and PA that is one of responsible ingredients for ameliorating mechanical hyperalgesia in diabetes via the inhibition of Nav1.7 VGSC current at least.

Diterpenoid alkaloids from Delphinium naviculare var. lasiocarpum with their antifeedant activity on Spodoptera exigua.

A new lycoctonine diterpenoid alkaloid navicularine, along with eighteen known diterpenoid alkaloids, were isolated from the whole plant of Delphinium naviculare var. lasiocarpum. Their structures were elucidated on the base of extensive spectroscopic analysis (HR-ESI-MS and NMR) and comparison with data reported in the literature. Most of alkaloids were tested for their antifeedant activity against larvae of Spodoptera exigua (Hübner). The compound shawurensine showed considerably potent antifeedant activity (EC50 = 0.42 and 0.81 mg/cm2 in the choice test and no choice test, respectively).

Antiviral activity of aconite alkaloids from Aconitum carmichaelii Debx.

Four diterpenoid alkaloids, namely, (a) hypaconitine, (b) songorine, (c) mesaconitine and (d) aconitine, were isolated from the ethanol root extract of Aconitum carmichaelii Debx. The antiviral activities of these alkaloids against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV) were evaluated. Antiviral activity test in vivo showed that compounds a and c, which were C19-diterpenoid alkaloids, showed inactivation efficacy values of 82.4 and 85.6% against TMV at 500 µg/mL, respectively. By contrast, compound c presented inactivation activity of 52.1% against CMV at 500 µg/mL, which was almost equal to that of the commercial Ningnanmycin (87.1% inactivation activity against TMV and 53.8% inactivation activity against CMV). C19-Diterpenoid alkaloids displayed moderate to high antiviral activity against TMV and CMV at 500 µg/mL, dosage plays an important role in antiviral activities. This paper is the first report on the evolution of aconite diterpenoid alkaloids for antiviral activity against CMV.

C19-Norditerpenoid Alkaloids from Aconitum szechenyianum.

Three new C19-norditerpenoid alkaloids (1⁻3), along with two known C19-norditerpenoid alkaloids (4,5), have been isolated from Aconitum szechenyianum. Based on extensive spectroscopic techniques (1D, 2D-NMR, IR, and MS) and chemical methods, their structures were established as szechenyianine D (1), szechenyianine E (2), szechenyianine F (3), 8-O-methyl-14-benzoylaconine (4), and spicatine A (5). The immunosuppressive effects of compounds 1⁻5 were studied using a ConA-induced or LPS-induced splenocyte proliferation model. In vitro tests showed that Compounds 2, 4, and 5 suppressed ConA-induced or LPS-induced splenocyte proliferation in a concentration-dependent manner. The CC50/IC50 values of 2, 4, and 5 suggested that these compounds were potential immunosuppressive agents for the treatment of autoimmune diseases characterized by arthritis, such as rheumatoid arthritis.

[ALKALOIDS OF UNDERGROUND PARTS OF GEORGIAN FLORA'S ACONITUM ORIENTALE MILL. AND ACONITUM NASUTUM FISCH. EX REICHEMB AND THEIR BIOLOGICAL ACTIVITY].

The aim of research was to study underground parts of Aconitum orientale Mill and Aconitum nasutum Fisch exReichemb for the composition of biological active diterpenic alkaloids. The research object was underground parts of Aconitum species. Alkaloids sum was received from raw-material which was alkalined beforehand with chloroform extraction. From the results of research we established, that both species of Georgian flora's Aconitum contains alkaloids: lappaconitine, aconitine, karakoline. Underground parts of Aconitum orientale and Aconitum nasutum differ from eath other with composition of alkaloids spectrum. Underground parts of Aconitum orientale contains bases: ranaconitine, gigactonine, licoctonine, but underground parts of Aconitum nasutum contains: talitizamine, kamakonine, aconosine. Alkaloids' summary substances, which were received from underground parts of Aconitum species spread in Georgia, showed selective cytotoxic activity towards A-549 (lung carcinoma), DLD-1 (intestine adenocarcinoma), WS-1 (human normal fibroblasts).

Selective dual cholinesterase inhibitors from Aconitum laeve.

New lycoctonine-type dual cholinesterase inhibitor, swatinine-C (1), along with three known norditerpenoid alkaloids, hohenackerine (2), aconorine (5) and lappaconitine (6) and two synthetically known but phytochemically new benzene derivatives, methyl 2-acetamidobenzoate (3) and methyl 4-[2-(methoxycarbonyl)anilino]-4-oxobutanoate (4), was isolated from the roots of A. laeve. Structures of new and known compounds (1-6) were established on the basis of latest spectroscopic techniques and by close comparison with the data available in literature. In vitro, compounds (1-6) were tested against AChE and BChE inhibitory activities. Compounds 1 and 2 showed competitive inhibition against AChE (IC50 = 3.7 µM, 4.53 µM) and BChE (IC50 = 12.23 µM, 9.94 µM), respectively. Compounds 5 and 6 showed promising noncompetitive type of inhibitory profile against AChE (IC50 = 2.51 and 6.13 µM) only. Compounds 3 and 4 showed weak inhibitory profile against both AChE and BChE.

De Novo RNA Sequencing and Expression Analysis of Aconitum carmichaelii to Analyze Key Genes Involved in the Biosynthesis of Diterpene Alkaloids.

Aconitum carmichaelii is an important medicinal herb used widely in China, Japan, India, Korea, and other Asian countries. While extensive research on the characterization of metabolic extracts of A. carmichaelii has shown accumulation of numerous bioactive metabolites including aconitine and aconitine-type diterpene alkaloids, its biosynthetic pathway remains largely unknown. Biosynthesis of these secondary metabolites is tightly controlled and mostly occurs in a tissue-specific manner; therefore, transcriptome analysis across multiple tissues is an attractive method to identify the molecular components involved for further functional characterization. In order to understand the biosynthesis of secondary metabolites, Illumina-based deep transcriptome profiling and analysis was performed for four tissues (flower, bud, leaf, and root) of A. carmichaelii, resulting in 5.5 Gbps clean RNA-seq reads assembled into 128,183 unigenes. Unigenes annotated as possible rate-determining steps of an aconitine-type biosynthetic pathway were highly expressed in the root, in accordance with previous reports describing the root as the accumulation site for these metabolites. We also identified 21 unigenes annotated as cytochrome P450s and highly expressed in roots, which represent candidate unigenes involved in the diversification of secondary metabolites. Comparative transcriptome analysis of A. carmichaelii with A. heterophyllum identified 20,232 orthogroups, representing 30,633 unigenes of A. carmichaelii, gene ontology enrichment analysis of which revealed essential biological process together with a secondary metabolic process to be highly enriched. Unigenes identified in this study are strong candidates for aconitine-type diterpene alkaloid biosynthesis, and will serve as useful resources for further validation studies.

Gram-scale purification of aconitine and identification of lappaconitine in Aconitum karacolicum.

Aconitum karacolicum from northern Kyrgyzstan (Alatau area) contains about 0.8-1% aconitine as well as other aconite derivatives that have already been identified. In this paper, we compare several methods for the further purification of an Aconitum karacolicum extract initially containing 80% of aconitine. Reverse-phase flash chromatography, reverse-phase semi-preparative HPLC, centrifugal partition chromatography (CPC) and recrystallization techniques were evaluated regarding first their efficiency to get the highest purity of aconitine (over 96%) and secondly their applicability in a semi-industrial scale purification process (in our case, 150g of plant extract). Even if the CPC technique shows the highest purification yield (63%), the recrystallization remains the method of choice to purify a large amount of aconitine as i) it can be easily carried out in safe conditions; ii) an aprotic solvent is used, avoiding aconitine degradation. Moreover, this study led us to the identification of lappaconitine in Aconitum karacolicum, a well-known alkaloid never found in this Aconitum species.

A new diterpenoid alkaloid isolated from Delphinium caeruleum.

The present study was designed to determine the chemical constituents of Delphinium caeruleum Jacq. ex Camb.. The chemical constituents were isolated and purified by column chromatography with silica gel, ODS, and Sephadex LH-20. Their structures were elucidated by IR, MS, and NMR. Ten compounds were obtained and identified as caerudelphinine A (1), lycoctonine (2), talitine B (3), talitine A (4), talitine C (5), tatsienine-V (6), d-magnoflorine (7), 2-trimethyl-ammonio-3-(3-indolyl) propionate (8), vakhmatine (9), and delatisine (10). Compound 1 was a new lycoctonine-type C19-diterpenoid alkaloid, and compounds 4-10 were isolated from this plant for the first time.

Isolation, crystal structure determination and cholinesterase inhibitory potential of isotalatizidine hydrate from Delphinium denudatum.

CONTEXT: Delphinium denudatum Wall (Ranunculaceae) is a rich source of diterpenoid alkaloids and is widely used for the treatment of various neurological disorders such as epilepsy, sciatica and Alzheimer's disease. OBJECTIVE: The present study describes crystal structure determination and cholinesterase inhibitory potential of isotalatazidine hydrate isolated from the aerial part of Delphinium denudatum. MATERIALS AND METHODS: Phytochemical investigation of Delphinium denudatum resulted in the isolation of isotalatazidine hydrate in crystalline form. The molecular structure of the isolated compound was established by X-ray diffraction. The structural data (bond length and angles) of the compound were calculated by Density Functional Theory (DFT) using B3LYP/6-31 + G (p) basis set. The cholinesterase inhibitory potential of the isolated natural product was determined at various concentrations (62.5, 125, 250, 500 and 1000 µg/mL) followed by molecular docking to investigate the possible inhibitory mechanism of isotalatazidine hydrate. RESULTS: The compound crystallized in hexagonal unit cell with space group P65. Some other electronic properties such as energies associated with HOMO-LUMO, band gaps, global hardness, global electrophilicity, electron affinity and ionization potential were also calculated by means of B3LYP/6-31 + G (p) basis set. The compound showed competitive type inhibition of both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with IC50 values of 12.13 µM and 21.41 µM, respectively. DISCUSSION AND CONCLUSION: These results suggest that isotalatazidine hydrate is a potent dual cholinesterase inhibitor and can be used as a target drug in Alzheimer diseases. This is first report indicating isotalatazidine hydrate with anticholinesterase potential.

Diterpenoid alkaloids of Aconitum laciniatum and mitigation of inflammation by 14-O-acetylneoline in a murine model of ulcerative colitis.

Aconitum laciniatum is used in Bhutanese traditional medicine for treating various chronic infections and inflammatory conditions. We carried out in-depth isolation and characterization of the phytochemicals from the root component and determined the anti-inflammatory effects of the isolated compounds against chemically-induced colitis in mice. Five diterpenoid alkaloids - pseudaconitine, 14-veratroylpseudaconine, 14-O-acetylneoline, neoline, and senbusine A - were isolated from A. laciniatum for the first time. Two of the alkaloids were tested for anti-inflammatory properties in the TNBS-induced colitis model in mice. Various parameters were measured to assess pathology including weight loss, clinical and macroscopic scores, histological structure and IFN-γ production in the gut. Of the two alkaloids tested, 14-O-acetylneoline showed significant protection against different parameters of colitic inflammation. Compared to control mice that received TNBS alone, mice treated with 14-O-acetylneoline experienced significantly less weight loss and had significantly lower clinical scores, macroscopic pathology and grades of histological inflammation. Moreover, colonic IFN-γ mRNA levels were significantly reduced in mice that received 14-O-acetylneoline compared to control mice that received TNBS alone. This alkaloid is now considered a novel anti-colitis drug lead compound.

The influences of aconitine, an active/toxic alkaloid from aconitum, on the oral pharmacokinetics of CYP3A probe drug buspirone in rats.

Aconitine (AC), an active/toxic alkaloid from Aconitum species, is commonly present in Traditional Chinese Medicine (TCM) prescriptions because of the great effectiveness of Aconitum for the treatment of rheumatoid arthritis, cardiovascular diseases, and tumors in clinic. Buspirone (BP) is a sensitive CYP3A probe drug that is administered through oral/intravenous routes as recommended by the U.S. Food and Drug Administration. This study aims to investigate the influences of AC (0.125 mg/kg, oral) on first-pass (intestinal and hepatic) CYP3A activity by using oral BP as the probe in rats. The pharmacokinetics of oral buspirone hydrochloride at different doses (12.5, 25, and 50 mg/kg) were conducted. The pharmacokinetics of oral BP in rats pretreated with single dose or multiple doses (7-day) of AC were investigated. The plasma concentrations of BP and its major metabolites [1-(2-pyrimidinyl)piperazine (1-PP) and 6'-hydroxybuspirone (6'-OH-BP)] were determined. The formation ratios of 1-PP and 6'-OH-BP from BP (AUC0-∞ of 1-PP/AUC0-∞ of BP and AUC0-∞ of 6'-OH-BP/AUC0-∞ of BP values) showed no alternation when the dose of BP changed. Single dose of AC decreased the AUC0-∞ of BP by 53% but increased the formation ratio of 6'-OH-BP by 74% (P<0.05). Multiple AC exposure increased the AUC0-∞ of BP by 110%, and the formation ratios of 1-PP and 6'-OH-BP from BP were increased by 229% and decreased by 95%, respectively (P<0.05). Conclusively, single/multiple AC exposure did not alter the first-pass CYP3A activity when using oral BP as probe in rats. Nevertheless, multiple AC exposure had markedly changed the production of BP metabolites.

Analgesic activity of diterpene alkaloids from Aconitum baikalensis.

We compared analgesic activities of individual alkaloids extracted from Baikal aconite (Aconitum baikalensis): napelline, hypaconitine, songorine, mesaconitine, 12-epinapelline N-oxide. The detected analgesic activity was comparable to that of sodium metamizole. The mechanisms of analgesia were different in diterpene alkaloids of different structure. The antinociceptive effect of atisine alkaloids (12-epinapelline N-oxide, songorine) was naloxonedependent and realized via opioid receptor modulation.

Distribution of toxic alkaloids in tissues from three herbal medicine Aconitum species using laser micro-dissection, UHPLC-QTOF MS and LC-MS/MS techniques.

Aconite poisoning continues to be a major type of poisoning caused by herbal drugs in many countries. Nevertheless, despite its toxic characteristics, aconite is used because of its valuable therapeutic benefits. The aim of the present study was to determine the distribution of toxic alkaloids in tissues of aconite roots through chemical profiling. Three species were studied, all being used in traditional Chinese Medicine (TCM) and traditional Indian medicine (Ayurveda), namely: Aconitum carmichaelii, Aconitum kusnezoffii and Aconitum heterophyllum. Laser micro-dissection was used for isolation of target microscopic tissues, such as the metaderm, cortex, xylem, pith, and phloem, with ultra-high performance liquid chromatography equipped with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS) employed for detection of metabolites. Using a multi-targeted approach through auto and targeted LC-MS/MS, 48 known compounds were identified and the presence of aconitine, mesaconitine and hypaconitine that are the biomarkers of this plant was confirmed in the tissues. These results suggest that the three selected toxic alkaloids were exclusively found in A. carmichaelii and A. kusnezoffii. The most toxic components were found in large A. carmichaelii roots with more lateral root projections, and specifically in the metaderm, cork and vascular bundle tissues. The results from metabolite profiling were correlated with morphological features to predict the tissue specific distribution of toxic components and toxicity differences among the selected species. By careful exclusion of tissues having toxic diester diterpenoid alkaloids, the beneficial effects of aconite can still be retained and the frequency of toxicity occurrences can be greatly reduced. Knowledge of tissue-specific metabolite distribution can guide users and herbal drug manufacturers in prudent selection of relatively safer and therapeutically more effective parts of the root. The information provided from this study can contribute towards improved and effective management of therapeutically important, nonetheless, toxic drug such as Aconite.

Three new diterpenoid alkaloids from the roots of Aconitum duclouxii.

Three new C19-diterpenoid alkaloids, ducloudines C (1), D (2), and E (3), were isolated from the roots of Aconitum duclouxii. Their structures were established on the basis of extensive spectroscopic analyses. Ducloudine C (1) is the first aconitine-type C19-diterpenoid alkaloid with a C=O group at C-3 and a C=C bond between C-1 and C-2. All compounds were tested for their biological activities against one pathogenic fungi and two pathogenic bacteria.

New alkaloids from Aconitum taipaicum and their cytotoxic activities.

Three new aconitine-type C19-diterpenoid alkaloids, taipeinines A-C (1-3), were isolated from the roots of Aconitum taipaicum. The chemical structures of these three compounds were established as (1α,6α,8α,14α,16α)-20-ethyl-8,14-dihydroxy-1,6,16-trimethoxy-4-(methoxymethyl)-aconitane (1), (1α,6α,8α,14α,16ß)-20-ethyl-8,14-dihydroxy-1,6,16-trimethoxy-4-(methoxymethyl)-aconitane (2) and (1α,6α,8α,14α,16α)-20-ethyl-1,8,14-trihydroxy-6,16-dimethoxy-4-(methoxymethyl)-aconitane (3), respectively, on the basis of spectroscopic analyses, mainly MS, 1D and 2D NMR. The cytotoxic activities of these compounds were also assayed, and the results were quite impressive.

[Effects of steaming and baking on content of alkaloids in Aconite Lateralis Radix (Fuzi)].

To study the effect of steaming and baking process on contents of alkaloids in Aconite Lateralis Radix (Fuzi), 13 alkaloids were analyzed by UPLC-MS/MS equipped with ESI ion source in MRM mode. In steaming process, the contents of diester-diterpenoid alkaloids decreased rapidly, the contents of monoester-diterpenoid alkaloids firstly increased, reached the peak at 40 min, and then deceased gradually. The contents of aconine alkaloids (mesaconine, aconine and hypaconine) increased all the time during processing, while the contents of fuziline, songorine, karacoline, salsolionl were stable or slightly decreased. In baking process, dynamic variations of alkaloids were different from that in the steaming process. Diester-diterpenoid alkaloids were degraded slightly slower than in steaming process. Monoester-diterpenoid alkaloids, aconine alkaloids and the total alkaloids had been destroyed at different degrees, their contents were significantly lower than the ones in steaming Fuzi at the same processing time. This experiment revealed the dynamic variations of alkaloids in the course of steaming and baking. Two processing methods which can both effectively remove the toxic ingredients and retain the active ingredients are simple and controllable, and are valuable for popularization and application.

[Aconitine analogues in wild Aconitum plants: contents toxicity to mice and decrease by boiling].

Simultaneous determination of four aconitine analogues (ACs) (AC; aconitine, HA; hypaconitine, JA; jesaconitine, MA; mesaconitine) in leaves and roots of wild Aconitum plants (Aconitum japonicum THUNBERG, Aconitum okuyamae Nakai) was carried out to elucidate the relation between toxicity to mice and ACs content determind by liquid chromatography tandem mass spectrometry. The total amounts of ACs in leaves, roots, petals and nectaries of Aconitum japonicum collected at Sagae-shi Tashiro were 5.9 µg/g, 928.1 µg/g, 46.1 µg/g, and 69.8 µg/g, respectively. Despite the high contents in nectary, commercial honey contained no ACs. Extract of wild Aconitum japonicum roots which contained ACs (2.69 mg/g) was administered to 5 mice orally at 1.0 g/kg (fresh root equivalent), and 2 mice died. On the other hand, 3 of 5 mice died after being given the standard AC (3.0 mg/kg, p.o.). These findings confirmed good coincidence between toxicity and quantitative values. Mice given extract of Aconitum okuyamae root (100 g/kg, p.o.) without ACs showed no toxic symptoms. Residual ACs in Aconitum leaves were examined after boiling. The remaining percentage of ACs in leaves after 0.5 minutes boiling was 31.6%, and the amount in the boiling water was 54.5%. MA is converted into benzoylmesaconine by hydrolysis (by boiling). Therefore food poisoning caused by Aconitum plants is explained by detection of benzoylmesaconine formed during food preparation.