The Experimental Approach to the Murder Case of Aconite Poisoning

Dearomative logic in natural product total synthesis

Covering: 2011 to 2022The natural world is a prolific source of some of the most interesting, rare, and complex molecules known, harnessing sophisticated biosynthetic machinery evolved over billions of years for their production. Many of these natural products represent high-value targets of total synthesis, either for their desirable biological activities or for their beautiful structures outright; yet, the high sp3-character often present in nature's molecules imparts significant topological complexity that pushes the limits of contemporary synthetic technology. Dearomatization is a foundational strategy for generating such intricacy from simple materials that has undergone considerable maturation in recent years. This review highlights the recent achievements in the field of dearomative methodology, with a focus on natural product total synthesis and retrosynthetic analysis. Disconnection guidelines and a three-phase dearomative logic are described, and a spotlight is given to nature's use of dearomatization in the biosynthesis of various classes of natural products. Synthetic studies from 2011 to 2021 are reviewed, and 425 references are cited.

Antagonistic effects of tetrodotoxin on aconitine-induced cardiac toxicity

Aconitine, well-known for its high cardiotoxicity, causes severe arrhythmias, such as ventricular tachycardia and ventricular fibrillation, by opening membrane sodium channels. Tetrodotoxin, a membrane sodium-channel blocker, is thought to antagonize aconitine activity. Tetrodotoxin is a potent blocker of the skeletal muscle sodium-channel isoform Na(v)1.4 (IC50 10 nM), but micromolar concentrations of tetrodotoxin are required to inhibit the primary cardiac isoform Na(v)1.5. This suggests that substantial concentrations of tetrodotoxin are required to alleviate the cardiac toxicity caused by aconitine. To elucidate the interaction between aconitine and tetrodotoxin in the cardiovascular and respiratory systems, mixtures of aconitine and tetrodotoxin were simultaneously administered to mice, and the effects on electrocardiograms, breathing rates, and arterial oxygen saturation were examined. Compared with mice treated with aconitine alone, some mice treated with aconitine-tetrodotoxin mixtures showed lower mortality rates and delayed appearance of arrhythmia. The decreased breathing rates and arterial oxygen saturation observed in mice receiving aconitine alone were alleviated in mice that survived after receiving the aconitine-tetrodotoxin mixture; this result suggests that tetrodotoxin is antagonistic to aconitine. When the tetrodotoxin dose is greater than the dose that can block tetrodotoxin-sensitive sodium channels, which are excessively activated by aconitine, tetrodotoxin toxicity becomes prominent, and the mortality rate increases because of the respiratory effects of tetrodotoxin. In terms of cardiotoxicity, mice receiving the aconitine-tetrodotoxin mixture showed minor and shorter periods of change on electrocardiography. This finding can be explained by the recent discovery of tetrodotoxin-sensitive sodium-channel cardiac isoforms (Na(v)1.1, 1.2, 1.3, 1.4 and 1.6).

Fatal aconitine intoxication or thyroid storm? A case report

The case of a female in the latter half of her teens found dead in her father's apartment is reported. A glass containing liquid and plant remnants was found at the death scene. There were no indications of any intervention or the application of force by a third party. Autopsy showed unremarkable findings. Toxicological investigations revealed lethal doses of aconitine, a highly poisonous alkaloid and the major active compound of Aconitum napellus, in all specimens. Plant remnants were identified as A. napellus leaves by a botanist and toxicological examination of the liquid in the glass on site showed extremely high concentrations of aconitine. Additionally, laboratory results revealed that the young female was suffering from thyrotoxicosis factitia, an uncommon form of hyperthyroidism caused by misuse or overdosing of thyroid hormones in order to loose weight. A rare but serious and often fatal complication of hyperthyroidism is thyroid storm. Eventually the condition of thyroid storm due to thyrotoxicosis factitia could have contributed to the woman's death from aconitine poisoning.

CE-electrochemiluminescence with ionic liquid for the facile separation and determination of diester-diterpenoid aconitum alkaloids in traditional Chinese herbal medicine

A CE-electrochemiluminescence(CE-ECL) detection system, CE/tris(2,2'-bipyridyl) ruthenium(II)ECL with ionic liquid, was established for the determination of diester-diterpenoid aconitum alkaloids (aconitine (AC), mesaconitine (MA) and hypaconitine (HA)) in traditional Chinese herbal medicine. Running buffer containing 25 mM borax-20 mM 1-ethyl-3-methylimidazolium tetrafluoroborate at pH 9.15 was used, which resulted in significant changes in separation and obvious enhancement in ECL intensity for AC, MA and HA with similar structures. End-column detection was achieved in 50 mM phosphate buffer with 5 mM Ru(bpy)₃²⁺ (pH 9.15) at applied detection voltage of 1.20 V when the distance between the Pt working electrode and outlet of capillary (50 cm × 25 μm id) was set at 150 μm. One single quantitative analysis of three alkaloids was achieved at a separation voltage of 15 kV within 10 min. Moreover, two extraction processes (ethanol extraction and ethyl ether extraction after basification) were investigated. The result showed that ethanol extraction process has higher extraction efficiency than ethyl ether extraction process. Under the optimized conditions, the detection limits of AC, MA and HA were 5.62 × 10(-8) , 2.78 × 10(-8) and 3.50 × 10(-9) mol/L (S/N=3), respectively. The method was successfully applied to determine the amounts of AC, MA and HA in the aconitum herbal samples.

An accidental case of aconite poisoning due to Kampo herbal medicine ingestion

An accidental case of aconite intoxication occurred after a patient took a therapeutic dose of Kampo herbal medicine containing Aconiti tuber, Uzu but had used the wrong decoction procedure. The poisoning was likely caused by an increased level of Aconitum alkaloids in the decoction; the patient developed aconite intoxication due to incomplete decoction. Aconitum alkaloid levels in the leftover solution which the patient had drunk and in the decoction extracted from 3g Uzu were determined. It was found that decoction makes the medicine safer to drink. Older individuals, especially those with dementia, have a higher risk of aconite poisoning because they sometimes do not boil the medicine appropriately.

Characterization of metabolites and cytochrome P450 isoforms involved in the microsomal metabolism of aconitine

Aconitine, a major Aconitum alkaloid, is well known for its high toxicity that induces severe arrhythmias leading to death. The current study investigated the metabolism of aconitine and the effects of selective cytochrome P450 (CYP) inhibitors on the metabolism of aconitine in rat liver microsomes. The metabolites were separated and assayed by liquid chromatography-ion trap mass spectrometry (LC/MS(n)) and further identified by comparison of their mass spectra and chromatographic behaviors with reference substances. Various selective inhibitors of CYP were used to identify the isoforms of CYP, that involved in the metabolism of aconitine. A total of at least six metabolites were found and characterized in rat liver microsomal incubations. Result showed that the inhibitor of CYP 3A had an inhibitory effect on aconitine metabolism in a concentration-dependant manner, the inhibitor of CYP1A1/2 had a modest inhibitory effect, whereas inhibitors of CYP2B1/2, 2D and 2E1 had no obvious inhibitory effects on aconitine metabolism. Aconitine might be metabolized by CYP 3A and CYP1A1/2 isoforms in rat liver microsome.

Effects of chronic administrations of aconitine on body weight and rectal temperature in mice

Aconitine, a major Aconitum alkaloid, is well known for its high toxicity that induces severe arrhythmias leading to death. However, aconitine has been used as one of the most popular compounds in Shino-Japanese traditional herbal medicine. Little has been reported concerned with the long-term effects of aconitine. Therefore, the authors investigated the physiological effects of chronic administrations of aconitine by determining the changes in body weight and rectal temperature of mice, compared with the concentrations of aconitine and its metabolites (benzoylaconine and aconine) in the liver and kidneys. The concentration ratio of aconitine to the total Aconitum alkaloids (from day 0 to 22; 90 min after the last administration) gradually decreased, whereas its metabolites increased until day 22. The body weight gain in aconitine-administered group was less than that of the control group until day 22. Transient rectal hypothermia occurred within 30 min after the last administration of aconitine. Then the rectal temperature gradually increased to normal level in respect to time. This study might reveal the possibilities that the drug metabolism of aconitine increased and the toxicity of aconitine decreased due to long-term administrations of aconitine.

Effects of long-term administrations of aconitine on electrocardiogram and tissue concentrations of aconitine and its metabolites in mice

Aconitum alkaloids are well known for their acute and high toxicity, for example, in the causation of severe arrhythmias leading to death. Aconitine, one of the major Aconitum alkaloids, is a highly toxic compound from the Aconitum species. However, there has been no studies reported on the influence of the chronic administration of aconitine. Thus, this study was conducted to investigate the influence of chronic administration of aconitine in experimental animal models. A dose of 1mg/kg per day was administered to the experimental animal models. We determined the concentration of aconitine and its metabolites (benzoylaconine and aconine) in organs and blood with gas chromatography/selected ion monitoring (GC/SIM). In addition, we concurrently recorded the electrocardiogram (ECG). Fifteen minutes after administration on day 0, the early aconitine administered group (acute group) revealed peak organ and blood concentration levels of aconitine with a gradual decrease, thereafter. The concentration of aconitine in organs and blood (from days 0 to 22; 90 min after the last administration of aconitine) gradually decreased according to repeated administration, whereas benzoylaconine and aconine increased. ECG revealed various types of arrhythmias. However, the frequency of arrhythmias remarkably decreased with time and repeated administration of aconitine. These results indicate two possibilities. First, the increase in the activity of aconitine metabolism. Secondly, the decrease of effectiveness to the heart due to long-term (chronic) administration of aconitine.

A column-switching LC/MS/ESI method for detecting tetrodotoxin and Aconitum alkaloids in serum

A liquid chromatography-mass spectrometry-electrospray ionization (LC/MS/ESI) method coupled with a column-switching technique has been developed for the determination of tetrodotoxin (TTX) and Aconitum alkaloids and their metabolites, such as aconitine, mesaconitine, hypaconitine, jesaconitine, benzoylaconine, benzoylmesaconine, benzoylhypaconine and 14-anisoylaconine, in serum. An on-column column-switching technique was employed to analyze TTX and Aconitum alkaloids and their metabolites without pretreatment of the serum. Combination of a multimode column with reversed phases and cation exchange for TTX, and use of a multimode column with reversed phases and a hydrophobic polymer column for Aconitum alkaloids and their metabolites provided successful separation and MS determination in ESI positive mode. A 100 microl serum sample was directly injected into a precolumn. For TTX monitored at m/z 320.1 in the selected ion monitoring mode, the calibration curve was linear within the range 0.1-100 ng/ml and the limit of detection was 0.1 ng/ml. For aconitine, mesaconitine, hypaconitine and jesaconitine, linear calibration curves were obtained up to 500 ng/ml and the limit of detection ranged from 0.2 to 1 ng/ml. For benzoylaconine, benzoylmesaconine, benzoylhypaconine and 14-anisoylaconine, linear calibration curves were obtained up to 500 ng/ml and the limit of detection ranged from 2 to 50 ng/ml. Recoveries from serum samples were within the range 78-119% for all the compounds studied.