Structures of Flavamine and Flavadine from Aconitum flavum

Aconitum pendulum and Aconitum flavum: A narrative review on traditional uses, phytochemistry, bioactivities and processing methods

ETHNOPHARMACOLOGICAL RELEVANCE

Composed of dried Aconitum pendulum and Aconitum flavum roots, Tiebangchui, is an important Tibetan medicine and has been traditionally and widely used as a remedy for cold and pain for thousands of years because of its extraordinary pharmacological activities. The toxicity and efficacy of Tiebangchui as a typical toxic traditional Tibetan medicine, are interdependent, and thus to make sure its safe use in clinics is also noteworthy.

AIM OF THE STUDY

This review aims to document and summarize critical and comprehensive information about traditional uses, phytochemistry, pharmacology, toxicology and processing methods of Tiebangchui. Perspectives for possible future investigations have been discussed.

MATERIALS AND METHODS

Relevant information about Tiebangchui (A. pendulum and A. flavum) was collected from internationally recognized electronic scientific databases, such as Web of Science, PubMed, Science Direct, Springer Link, ACS, and CNKI. Then, classic Tibetan medical books, such as Four Medical Tantra, and Jing Zhu Materia Medica, and official drug standards were reviewed.

RESULTS

A total of 95 chemical constituents have been isolated and identified from Tiebangchui, and most of them were diterpenoid alkaloids. These phytochemicals showed a wide range of pharmacological properties, such as anti-inflammation, anti-rheumatoid arthritis, analgesic, local anesthetic, anti-cancer and anti-bacterial activities. Hence, Tiebangchui is broadly used in hundreds of preparations to treat fever, arthritis, rheumatic arthralgia, traumatic injury, furuncle and swelling. Cardiotoxicity, neurotoxicity and gastrointestinal toxicity are the main toxic effects caused by the Aconitum alkaloids of Tiebangchui. Various processing methods, including steaming, decocting and sand-frying, and traditional Tibetan medicine processing methods, such as processing with Hezi decoction, Qingke wine and Zanba, are effective in attenuating toxicity while retaining efficacy.

CONCLUSIONS

The present review provides primary information of Tiebangchui, particularly for its traditional uses, botanical characteristics, phytochemicals, outstanding bioactivities and processing methods. However, studies that explored the in vivo pharmacokinetics and mechanism of Tiebangchui, as well as its quality markers, qualitative and quantitative analysis are still insufficient. Processing methods that attenuate toxicities, evaluations of efficacy, in vivo processes and biological effects, the mechanisms of processed products should be further explored.

Fifteen new diterpenoid alkaloids from the roots of Aconitum kirinense Nakai

Extensive phytochemical investigation from the roots of Aconitum kirinense Nakai led to the identification of fifteen new compounds, including four ranaconitine type C₁₈-diterpenoid alkaloids (kirisines A-D, 1-4), one lappaconitine type C₁₈-diterpenoid alkaloid (kirisine E, 5), seven denudatine type C₂₀-diterpenoid alkaloids (kirisines F-L, 6-12), and three napelline type C₂₀-diterpenoid alkaloids (kirisines M-O, 13-15), together with 25 known ones. Their structures were elucidated by extensive spectroscopic analyses. Among them, compounds 1 and 2 are rare diterpenoid alkaloid with 9,14-methylenedioxy group, and the latter also has a rare chloro-substituent. The diterpenoid alkaloids isolated were C₁₈, C₁₉ and C₂₀-category, which might provide further clues for understanding the chemotaxonomic significance of this plant. The isolated compounds were tested for neuroprotective activity and acetylcholinesterase inhibitory activity. Compounds 7, 18, 30 and 40 which exhibited moderate activity at 80 μM against acetylcholinesterase.

[Studies on structural elucidation of Aconitum diterpenoid alkaloid by LC-APCI-MS and effects of Aconitum diterpenoid alkaloid on cutaneous blood flow]

The chemical constituents of Aconitum yesoense var. macroyesoense and Aconitum japonicum were examined using high-resolution spectral analysis. Twelve novel alkaloids were isolated from A. yesoense var. macroyesoense together with 20 known alkaloids. Eight novel alkaloids were isolated from A. japonicum together with 15 known alkaloids. An HPLC-atmospheric pressure chemical ionization-mass spectrometry (HPLC-APCI-MS) method was useful for the simultaneous determination of 21 Aconitum alkaloids found in A. yesoense var. macroyesoense and A. japonicum. These compounds were fairly stable under the conditions used, and the protonated molecules or fragment ions characteristic of the molecule appeared as base peaks in the mass spectra and were used for selected ion monitoring. HPLC-APCI-MS is a very promising approach for structural investigations of positional isomers and stereoisomers. This method was applied successfully to stereoisomeric Aconitum alkaloids differing in configuration at C-1, -6, or -12. Comparison of the APCI spectra showed that the abundance of fragment ions was significantly higher for the C-1, -6, or -12 beta-form alkaloid than for C-1, -6, or -12 alpha-form alkaloid. The main alkaloid constituents in the root of A. yesoense var. macroyesoense, Aconitum alkaloids of the C20-diterpenoid type, kobusine and pseudokobusine, and their acyl derivatives were examined for their peripheral vasoactivities by measuring laser-flowmetrically the cutaneous blood flow in the hind foot of mice after intravenous administration. It is thought that the hydroxyl groups of alkaloids, especially a free OH group of pseudokobusine at C-6, were important for action on the peripheral vasculature leading to dilatation, and the results indicated that esterification of the hydroxyl group at C-15 with either anisoate, veratroate, or p-nitroben-zoate may contribute to enhancement of the activity of the parent alkaloids.