Diterpenoid Alkaloids and One Lignan from the Roots of Aconitum pendulum Busch

Two Novel Diterpenoid Alkaloids from Aconitum Pendulum

Two previously uncharacterized compounds, an aconitine-type C19-diterpenoid alkaloid (1) and a napelline-type diterpenoid alkaloid C20-diterpenoid alkaloid (2), as well as ten known compounds (3-12), were isolated from Aconitum pendulum. Their structures were elucidated based on spectroscopic data, including 1D and 2D NMR, IR, HR-ESI-MS, and single-crystal X-ray diffraction analysis. The anti-insecticidal activities of these compounds were evaluated by contact toxicity tests against two-spotted spider mites, and compounds 1, 2, and 9 showed moderate contact toxicity, with LC50 values of 0.86±0.09, 0.95±0.23, and 0.89±0.19 mg/mL, respectively. This study highlights the potential use of diterpenoid alkaloids as natural plant-derived pesticides for the management of plant pests.

Exploring the Biomedical Potential of Terpenoid Alkaloids: Sources, Structures, and Activities

Terpenoid alkaloids are recognized as a class of compounds with limited numbers but potent biological activities, primarily derived from plants, with a minor proportion originating from animals and microorganisms. These alkaloids are synthesized from the same prenyl unit that forms the terpene skeleton, with the nitrogen atom introduced through β-aminoethanol, ethylamine, or methylamine, leading to a range of complex and diverse structures. Based on their skeleton type, they can be categorized into monoterpenes, sesquiterpenes, diterpenes, and triterpene alkaloids. To date, 289 natural terpenoid alkaloids, excluding triterpene alkaloids, have been identified in studies published between 2019 and 2024. These compounds demonstrate a spectrum of biological activities, including anti-inflammatory, antitumor, antibacterial, analgesic, and cardioprotective effects, making them promising candidates for further development. This review provides an overview of the sources, chemical structures, and biological activities of natural terpenoid alkaloids, serving as a reference for future research and applications in this area.

Polysaccharides and Bioactive Phenolics from Aconitum septentrionale Roots

Aconitum septentrionale is known to contain toxic diterpene alkaloids, while other bioactive compounds in the plant remain unclear. The aim of this study was to explore the phenolic compounds and polysaccharides from the water extract of A. septentrionale roots. Fifteen phenolic compounds were isolated and identified by NMR and MS, including fourteen known and one new dianthramide glucoside (2-[[2-(β-D-glucopyranosyloxy)-5-hydroxybenzoyl]amino]-4,5-dihydroxybenzoic acid methyl ester, 14). One neutral (complex of glucans with minor amounts of mannans) and two acidic polysaccharide fractions (complexes of pectic polysaccharides and glucans) were also obtained. Hydroxytyrosol (1), hydroxytyrosol-1-O-β-glucoside (2) and bracteanolide A (7) inhibited the release of nitric oxide by dendritic cells. Magnoflorine (8) and 2-[[2-(β-D-glucopyranosyloxy)-5-hydroxybenzoyl]amino]-5-hydroxybenzoic acid methyl ester (12) inhibited 15-lipoxygenase, and bracteanolide A (7) was a moderate inhibitor of xanthine oxidase. This study is the first to describe the diversity of phenolics and polysaccharides from A. septentrionale and their anti-inflammatory and anti-oxidant activities.

Hezi inhibits Tiebangchui-induced cardiotoxicity and preserves its anti-rheumatoid arthritis effects by regulating the pharmacokinetics of aconitine and deoxyaconitine

ETHNOPHARMACOLOGICAL RELEVANCE

Tiebangchui (TBC, dried roots of Aconitum pendulum Busch. and Aconitum flavum Hand.-Mazz.) is a well-known Tibetan medicine for dispelling cold and relieving pain. In China, it is widely used in prevention and treatment of various diseases, such as rheumatoid arthritis (RA), traumatic injury, and fracture. However, its cardiotoxicity and neurotoxicity seriously restrict its clinical application. Traditionally, Hezi (HZ, dry ripe fruit of Terminalia chebula Retz. and Terminalia chebula Retz. var. tomentella Kurt.) is generally used in combination with TBC for the purpose of toxicity reducing and efficacy enhancing, but so far we still can't clearly elucidate the compatibility effect and mechanism of the classical herbal pair.

AIM OF STUDY

To investigate the compatibility effect and mechanism of TBC co-administered with HZ.

METHODS

In the present study, we clarified the cardioprotective role of HZ on the cardiotoxicity induced by TBC. The electrocardiogram, the levels of serum cardiac troponin T (cTnT), the activities of cardiac superoxide dismutase (SOD), malonaldehyde (MDA), and histopathology of heart tissue have been determined in each group. Meanwhile, the anti-RA effect of each group was investigated by paw swelling measurement and histopathological examination of synovial. To explore the underlying mechanism, we performed the pharmacokinetic studies of aconitine (AC) and deoxyaconitine (DE) in TBC group and TBC + HZ group by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) system.

RESULTS

TBC co-administered with HZ could significantly inhibit the increased heart rate and the prolonged QTc interval induced by TBC (p < 0.01). And TBC + HZ group had lower levels of serum cTnT, cardiac MDA, and higher levels of cardiac SOD compared with TBC group (p < 0.01). In addition, the combination of TBC and HZ could preserve the anti-RA effect of TBC. Both TBC administration alone and TBC + HZ combination administration could effectively alleviate the paw swelling (p < 0.01). Furthermore, TBC co-administered with HZ could significantly decrease the area under the concentration-time curve (AUC_(0-∞)) and maximum concentration (C_max) of AC and DE comapred with TBC administration alone (p < 0.01 or p < 0.05). Meanwhile, it was observed that the time to reach the peak concentration (T_max), elimination half-life (t_1/2), mean retention time (MRT) of AC and DE in TBC group were significantly higher than those in TBC + HZ group (p < 0.01 or p < 0.05).

CONCLUSIONS

TBC co-administered with HZ could reduce TBC-induced cardiotoxicty and preserve its anti-RA efficacy. The underlying mechanism is associated with the change of pharmacokinetic process of AC and DE.

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.

The diterpenoid alkaloids

The diterpenoid alkaloids are a family of extremely important natural products that have long been a research hotspot due to their myriad of intricate structures and diverse biological properties. This chapter systematically summarizes the past 11 years (2009-2019) of studies on the diterpenoid alkaloids, including the "so-called" atypical ones, covering the classification and biogenetic relationships, phytochemistry together with 444 new alkaloids covering 32 novel skeletons and the corrected structures, chemical reactions including conversion toward toxoids, synthetic studies, as well as biological activities. It should be noted that the synthetic studies, especially the total syntheses of various diterpenoid alkaloids, are for the first time reviewed in this treatise. This chapter, in combination with our four previous reviews in volumes 42, 59, 67, and 69, will present to the readers a more completed and updated profile of the diterpenoid alkaloids.

Diterpenoid Alkaloids from the Aerial Parts of Aconitum flavum Hand.-Mazz

Sixteen diterpenoid alkaloids (DAs), including six aconitine-type alkaloids (5 and 9 - 13), seven 7,17-seco-aconitine-type alkaloids (1 - 4, 6 - 8), two napelline-type alkaloids (14 and 15) as well as one veatchine-type alkaloid (16), were isolated from the aerial parts of Aconitum flavum Hand.-Mazz. In which, flavumolines A - D (1 - 4) were four new ones, and flavumoline E (5) was reported as natural compound for the first time. Their chemical structures were elucidated by the analysis of extensive spectroscopic data. The inhibitory activities of these isolates on Cav3.1 low voltage-gated Ca2+ channel, NO production in LPS-activated RAW264.7cells, five human tumor cell lines, as well as acetylcholinesterase (AChE) were tested.

Tangutidines A-C, Three Amphoteric Diterpene Alkaloids from Aconitum tanguticum

Three new diterpene alkaloids, tangutidines A-C (1-3), and four known alkaloids (4-7) were isolated from the whole plant of Aconitum tanguticum, from which amphoteric diterpene alkaloids (1-3) were obtained for the first time. The structures of 1-3 were elucidated by detailed interpretation of spectroscopic data, including MS and NMR data. All of them were evaluated for their cytotoxic activities.

A systematic review of pharmacological activities, toxicological mechanisms and pharmacokinetic studies on Aconitum alkaloids

The tubers and roots of Aconitum (Ranunculaceae) are widely used as heart medicine or analgesic agents for the treatment of coronary heart disease, chronic heart failure, rheumatoid arthritis and neuropathic pain since ancient times. As a type of natural products mainly extracted from Aconitum plants, Aconitum alkaloids have complex chemical structures and exert remarkable biological activity, which are mainly responsible for significant effects of Aconitum plants. The present review is to summarize the progress of the pharmacological, toxicological, and pharmacokinetic studies of Aconitum alkaloids, so as to provide evidence for better clinical application. Research data concerning pharmacological, toxicological and pharmacokinetic studies of Aconitum alkaloids were collected from different scientific databases (PubMed, CNKI, Google Scholar, Baidu Scholar, and Web of Science) using the phrase Aconitum alkaloids, as well as generic synonyms. Aconitum alkaloids are both bioactive compounds and toxic ingredients in Aconitum plants. They produce a wide range of pharmacological activities, including protecting the cardiovascular system, nervous system, and immune system and anti-cancer effects. Notably, Aconitum alkaloids also exert strong cardiac toxicity, neurotoxicity and liver toxicity, which are supported by clinical studies. Finally, pharmacokinetic studies indicated that cytochrome P450 proteins (CYPs) and efflux transporters (ETs) are closely related to the low bioavailability of Aconitum alkaloids and play an important role in their metabolism and detoxification in vivo.

Chemical constituents in different parts of seven species of Aconitum based on UHPLC-Q-TOF/MS

Aconitum L., the main source of Aconitum medicinal materials, is rich in diterpenoid alkaloids. Several drugs derived from diterpenoid alkaloids are widely used to the current clinical treatment of pain, inflammation, and other symptoms. This paper aims to clarify the main metabolites and distribution of diterpenoid alkaloids in different parts of Aconitum plants. To that end, 7 species of Aconitum from three subgenera were analyzed by UHPLC-Q-TOF-MS under identical conditions. The fragmentation regularity of various types of diterpene alkaloids were determined and a total of 126 metabolites were identified by comparing the reference material and secondary mass spectrometry, with the literature. 67, 49, 17, 41, 14, 17 and 21 metabolites were identified from Aconitum carmichaeli, Aconitum stylosum, Aconitum sinomontanum, Aconitum vilmorinianum, Aconitum pendulum, Aconitum tanguticum and Aconitum gymnandrum, respectively. Meanwhile, the structure type of A. carmichaeli, A. stylosum, A. vilmorinianum, A. pendulum, A. gymnandrum were identified as C₁₉ type, A. sinomontanum was C₁₈ type, while A. tanguticum was C₂₀ type. A high similarity of metabolites was found between A. stylosum and A. vilmorinianum. The quantitative analysis of 19 compounds and the relative peak area of all metabolites which obtained through internal standard berberine, highlighted compounds like karakoline, talatisamine and atisine as references for future study of metabolic pathways. Furthermore, results from metabolites distribution and relative peak area analysis suggest that the leaf of A. carmichaeli, the leaf and stem of A. stylosum and A. vilmorinianum, and the flower of A. pendulum have potential as medicinal resources and are worth further development. These results establish a foundation for the comprehensive utilization of Aconitum resources.

Acotarines A-G, new diterpenoid alkaloids from Aconitum taronense induce lysosomal biogenesis

Seven new diterpenoid alkaloids, acotarines A-G (1-7), along with four known diterpenoid alkaloids, were isolated from Aconitum taronense. Their structures were established by 1D, 2D NMR spectra and HRESIMS data. Acotarine A (1) represents a franchetine-type alkaloid characterized by a N-butanone moiety. All the compounds were tested for their activities to induce lysosomal biogenesis through LysoTracker Red staining, compounds acotarines B (2), E (5), F (6), indaconitine (8), 7,8-epoxy-franchetine (9), and 6-epiforesticine (10) showed inducing lysosomal biogenesis activity.