8-O-Azeloyl-14-benzoylaconine: A new alkaloid from the roots of Aconitum karacolicum Rapcs and its antiproliferative activities

A review on efforts for improvement in medicinally important chemical constituents inAconitum through biotechnological interventions

The genus Aconitum belongs to the family Ranunculaceae, is endowed with more than 350 species on the earth. Medicinally important aconitine type of diterpenoid alkaloids are the characteristic compounds in most of the Aconitum species. The present review endeavored the major research carried out in the field of genetic resource characterization, pharmacological properties, phytochemistry, major factors influencing quantity, biosynthetic pathways and processing methods for recovery of active ingredients, variety improvement, propagation methods, and important metabolite production through cell/organ culture of various Aconitum species. More than 450 derivatives of aconitine-type C19 and C20-diterpenoid alkaloids along with a few other non-alkaloidal compounds, such as phenylpropanoids, flavonoids, terpenoids, and fatty acids, have been identified in the genus. A few Aconitum species and their common diterpenoid alkaloid compounds are also well characterized for analgesic, inflammatory and cytotoxic properties. However, the different isolated compound needs to be validated for supporting other traditional therapeutical uses of the plant species. Aconitine alkaloids shared common biosynthesis pathway, but their diversification mechanism remains unexplored in the genus. Furthermore, the process needs to be developed on secondary metabolite recovery, mass-scale propagation methods, and agro-technologies for maintaining the quality of products. Many species are losing their existence in nature due to over-exploitation or anthropogenic factors; thus, temporal monitoring of the population status in its habitat, and suitable management programs for ascertaining conservation needs to be developed.

Aconiti Lateralis Radix Praeparata as Potential Anticancer Herb: Bioactive Compounds and Molecular Mechanisms

Aconiti Lateralis Radix Praeparata (Fuzi in Chinese) is a traditional herbal medicine widely used in China and other Asian countries. In clinical practice, it is often used to treat heart failure, rheumatoid arthritis, and different kinds of pains. Fuzi extract and its active ingredients exert considerable anticancer, anti-inflammatory, and analgesic effects. The main chemical substances of Fuzi include alkaloids, polysaccharides, flavonoids, fatty acids, and sterols. Among of them, alkaloids and polysaccharides are responsible for the anticancer efficacy. Most bioactive alkaloids in Fuzi possess C19 diterpenoid mother nucleus and these natural products show great potential for cancer therapy. Moreover, polysaccharides exert extraordinary tumor-suppressive functions. This review comprehensively summarized the active ingredients, antineoplastic effects, and molecular mechanisms of Fuzi by searching PubMed, Web of Science, ScienceDirect, and CNKI. The anticancer effects are largely attributed to inducing apoptosis and autophagy, inhibiting proliferation, migration and invasion, regulating body immunity, affecting energy metabolism, as well as reversing multidrug resistance. Meanwhile, several signaling pathways and biological processes are mainly involved, such as NF-κB, EMT, HIF-1, p38 MAPK, PI3K/AKT/mTOR, and TCA cycle. Collectively, alkaloids and polysaccharides in Fuzi might serve as attractive therapeutic candidates for the development of anticancer drugs. This review would lay a foundation and provide a basis for further basic research and clinical application of Fuzi.

Design, synthesis, and biological evaluation of arylmethylpiperidines as Kv1.5 potassium channel inhibitors

Kv1.5 potassium channel, encoded by KCNA5, is a promising target for the treatment of atrial fibrillation, one of the common arrhythmia. A new series of arylmethylpiperidines derivatives based on DDO-02001 were synthesised and evaluated for their ability to inhibit Kv1.5 channel. Among them, compound DDO-02005 showed good inhibitory activity (IC₅₀ = 0.72 μM), preferable anti-arrhythmic effects and favoured safety. These results indicate that DDO-02005 can be a promising Kv1.5 inhibitor for further studies.

Two New Alkaloids from Fuzi and Their Metabolites Study

Former study suggests alkaloids from herbs of Aconitum genus plants possess excellent bioactivities, which exert great value for related deeper chemical constituent investigation. Herein, chemical isolation was performed and four alkaloids were isolated from Fuzi, of which two were new ones, and the other two were reported NMR data for the first time. Their chemical structures were identified by NMR data, high resolution MS, UV and IR analysis. Additionally, the MS fragmentation patterns were explored, formerly, that of hetisane alkaloid was rarely reported, and fragmentation mechanism of the diagnostic ion was proposed. Based on these fragment pathway, metabolites and metabolic pathways of four compounds were investigated in rat liver microsomes using UPLC-Q/TOF-MS, and dehydrogenation product was firstly found from metabolites of hetisane alkaloid.

Norditerpenoid alkaloids from Delphinium pseudoaemulans C. Y. Yang et B. Wang

Eight previously undescribed norditerpenoid alkaloids, pseudophnines A-D, pseudorenines A-B, and pseudonidines A-B, together with ten known norditerpenoid alkaloids, tianshanisine E, sharwuphinine B, potanisine A, lycoctonine, delbruline, isondelpheline, delavaines A-B, and shawurenines A-B were isolated from the whole plant of Delphinium pseudoaemulans C. Y. Yang et B. Wang. Their structures were established on the basis of spectroscopic analyses, including HR-ESI-MS, 1D and 2D NMR analysis. Additionally, no cytotoxicity was observed against A549 and HeLa cancer cells of these diterpenoid alkaloids when evaluated in vitro using the MTT method.

Qualitative and quantitative analysis of lipo-alkaloids and fatty acids in Aconitum carmichaelii using LC-MS and GC-MS

INTRODUCTION

Lipo-alkaloid (LA) is a kind of C₁₉ -norditerpenoid alkaloid in Aconitum species, which usually contains an aconitane skeleton and one or two fatty acid residues.

OBJECTIVE

To qualify and quantify the fatty acids and lipo-alkaloids in Aconitum carmichaelii.

METHODOLOGY

An ultra-high performance liquid chromatography-triple quadrupole-mass spectrometry (UHPLC-QQQ-MS) method was established to quantify LAs, while the free fatty acids were identified by gas chromatography-mass spectrometry (GC-MS) and ultra-high performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UHPLC-Q-TOF-MS).

RESULTS

Six major LAs (1-6) containing linoleic, palmitic, and oleic acid residues as side chains were quantified. Eighteen fatty acids were determined by GC-MS, and 15 were detected as the side chains of LAs. The LAs containing these 15 fatty acid residues accounted for about a third of the total identified LAs. Moreover, the contents of linoleic, palmitic, and oleic acids were highest. In addition, 12 oxygenated fatty acids were also identified by UHPLC-Q-TOF-MS for the first time.

CONCLUSION

The positive correlation between free fatty acids and LAs in A. carmichaelii indicated that the types and contents of LAs were influenced by free fatty acids.

Two decades of advances in diterpenoid alkaloids with cytotoxicity activities

The important pharmacological activities and structural complexity of diterpenoid alkaloids have long stimulated strong scientific interest; some of these naturally abundant compounds have been reported to be highly promising for treating cancer.

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.

Anticancer Activities of C18-, C19-, C20-, and Bis-Diterpenoid Alkaloids Derived from Genus Aconitum

Cancer is one of the most common lethal diseases, and natural products have been extensively studied as anticancer agents considering their availability, low toxicity, and economic affordability. Plants belonging to the genus Aconitum have been widely used medically in many Asian countries since ancient times. These plants have been proven effective for treating several types of cancer, such as lung, stomach, and liver cancers. The main effective components of Aconitum plants are diterpenoid alkaloids—which are divided into C₁₈-, C₁₉-, C₂₀-, and bis-diterpenoid alkaloids—are reportedly some of the most promising, naturally abundant compounds for treating cancer. This review focuses on the progress of diterpenoid alkaloids with different structures derived from Aconitum plants and some of their derivatives with potential anticancer activities. We hope that this work can serve as a reference for further developing Aconitum diterpenoid alkaloids as anticancer agents.

Identification of Oxygenated Fatty Acid as a Side Chain of Lipo-Alkaloids in Aconitum carmichaelii by UHPLC-Q-TOF-MS and a Database

Lipo-alkaloid is a kind of C19-norditerpenoid alkaloid usually found in Aconitum species. Structurally, they contain an aconitane skeleton and one or two fatty acid moieties of 3–25 carbon chains with 1–6 unsaturated degrees. Analysis of the lipo-alkaloids in roots of Aconitum carmichaelii resulted in the isolation of six known pure lipo-alkaloids (A1–A6) and a lipo-alkaloid mixture (A7). The mixture shared the same aconitane skeleton of 14-benzoylmesaconine, but their side chains were determined to be 9-hydroxy-octadecadienoic acid, 13-hydroxy-octadecadienoic acid and 10-hydroxy-octadecadienoic acid, respectively, by MS/MS analysis after alkaline hydrolysis. To our knowledge, this is the first time of the reporting of the oxygenated fatty acids as the side chains in naturally-occurring lipo-alkaloids. In order to identify more lipo-alkaloids, a compound database was established based on various combinations between the aconitane skeleton and the fatty acid chain, and then, the identification of lipo-alkaloids was conducted using the database, UHPLC-Q-TOF-MS and MS/MS. Finally, 148 lipo-alkaloids were identified from A. carmichaelii after intensive MS/MS analysis, including 93 potential new compounds and 38 compounds with oxygenated fatty acid moieties.

Evaluation of Aconitum diterpenoid alkaloids as antiproliferative agents

Little information has been reported on the antitumor effects of the diterpenoid alkaloid constituents of Aconitum plants, used in the herbal drug 'bushi'. This study was aimed at determining the antitumor activities of Aconitum C19-and C20-diterpenoid alkaloids and synthetic derivatives against lung (A549), prostate (DU145), nasopharyngeal (KB), and vincristine-resistant nasopharyngeal (KB-VIN) cancer cell lines. Newly synthesized C20-diterpenoid alkaloid derivatives showed substantial suppressive effects against all human tumor cell lines tested. In contrast, natural and derivatized C19-diterpenoid alkaloids showed only a slight or no effect. Most of the active compounds were hetisine-type C20-diterpenoid alkaloids, specifically kobusine and pseudokobusine analogs with two different substitution patterns, C-11 and C-11,15. Notably, several C20-diterpenoid alkaloids were more potent against multidrug-resistant KB subline KB-VIN cells. Pseudokobusine 11-3'-trifluoromethylbenzoate (94) is a possible promising new lead meriting additional evaluation against multidrug-resistant tumors.

Green surfactant of marine origin exerting a cytotoxic effect on cancer cell lines

The present work reveals the efficacy of a marine antimicrobial lipopeptide biosurfactant in blocking proliferation of breast cancer and colon cancer cell lines, without displaying any significant antioxidant activity.

A review on phytochemistry, pharmacology and toxicology studies of Aconitum

Objectives

A number of species belonging to herbal genus Aconitum are well-known and popular for their medicinal benefits in Indian, Vietnamese, Korean, Japanese, Tibetan and Chinese systems of medicine. It is a valuable drug as well as an unpredictable toxic material. It is therefore imperative to understand and control the toxic potential of herbs from this genus. In this review, the ethnomedicinal, phytochemistry, pharmacology, structure activity relationship and toxicology studies of Aconitum were presented to add to knowledge for their safe application.

Key findings

A total of about 76 of all aconite species growing in China and surrounding far-east and Asian countries are used for various medical purposes. The main ingredients of aconite species are alkaloids, flavonoids, free fatty acids and polysaccharides. The tuberous roots of genus Aconitum are commonly applied for various diseases such as rheumatic fever, painful joints and some endocrinal disorders. It stimulates the tip of sensory nerve fibres. These tubers of Aconitum are used in the herbal medicines only after processing. There remain high toxicological risks of the improper medicinal applications of Aconitum. The cardio and neurotoxicities of this herb are potentially lethal. Many analytical methods have been reported for quantitatively and qualitatively characterization of Aconitum.

Summary

Aconitum is a plant of great importance both in traditional medicine in general and in TCM in particular. Much attention should be put on Aconitum because of its narrow therapeutic range. However, Aconitum's toxicity can be reduced using different techniques and then benefit from its pharmacological activities. New methods, approaches and techniques should be developed for chemical and toxicological analysis to improve its quality and safety.

Recent Progress of Research on Herbal Products Used in Traditional Chinese Medicine: the Herbs belonging to The Divine Husbandman's Herbal Foundation Canon ( Shén Nóng Běn Cǎo Jīng)

This article will review selected herbal products from Chinese Materia Medica that are used in Traditional Chinese Medicine. The herbs come from the upper, middle, and lower class medicines as listed in The Divine Husbandman's Herbal Foundation Canon (神農本草經 Shén Nóng Běn Cǎo Jīng). The review will focus on the active constituents of the herbs and their bioactivities, with emphasis on the most recent progress in research for the period of 2003 to 2011.

Cytotoxic esterified diterpenoid alkaloid derivatives with increased selectivity against a drug-resistant cancer cell line

C-6 Esterifications of delpheline (1) were carried out to provide 20 new diterpenoid alkaloid derivatives (4-22, 24). Three natural alkaloids (1-3) and all synthesized compounds (4-25) were evaluated for cytotoxic activity against lung (A549), prostate (DU145), nasopharyngeal (KB), and vincristine-resistant nasopharyngeal (KB-VIN) cancer cell lines and interestingly, showed an improved drug resistance profile compared to paclitaxel. Particularly, 6-(4-fluoro-3-methylbenzoyl)delpheline (22) displayed 2.6-fold greater potency against KB-VIN cells compared with the parental non-drug resistant KB cells. 6-Acylation of 1 appears to be critical for producing cytotoxic activity in this alkaloid class and a means to provide promising new leads for further development into antitumor agents.

Evidence for aconitine-induced inhibition of delayed rectifier K(+) current in Jurkat T-lymphocytes

Aconitine (ACO) is a highly toxic diterpenoid alkaloid and known to exert the immunomodulatory action. However, whether it has any effects on ion currents in immune cells remains unknown. The effects of ACO and other related compounds on ion currents in Jurkat T-lymphocytes were investigated in this study. ACO suppressed the amplitude of delayed-rectifier K(+) current (I(K(DR))) in a time- and concentration-dependent manner. Margatoxin (100 nM), a specific blocker of K(V)1.3-encoded current, decreased the I(K(DR)) amplitude in these cells and the ACO-induced inhibition of I(K(DR)) was not reversed by 1-ethyl-2-benzimidazolinone (30 μM) or nicotine (10 μM). The IC(50) value for ACO-mediated inhibition of I(K(DR)) was 5.6 μM. ACO accelerated the inactivation of I(K(DR)) with no change in the activation rate of this current. Increasing the ACO concentration not only reduced the I(K(DR)) amplitude, but also accelerated the inactivation time course of the current. With the aid of minimal binding scheme, the inhibitory action of ACO on I(K(DR)) was estimated with a dissociation constant of 6.8 μM. ACO also shifted the inactivation curve of I(K(DR)) to a hyperpolarized potential with no change in the slope factor. Cumulative inactivation for I(K(DR)) was enhanced in the presence of ACO. In Jurkat cells incubated with amiloride (30 μM), the ACO-induced inhibition of I(K(DR)) remained unaltered. In RAW 264.7 murine macrophages, ACO did not modify the kinetics of I(K(DR)), although it suppressed I(K(DR)) amplitude. Taken together, these effects can significantly contribute to its action on functional activity of immune cells if similar results are found in vivo.

Structure-activity relationships and the cytotoxic effects of novel diterpenoid alkaloid derivatives against A549 human lung carcinoma cells

The cytotoxicity of three alkaloids from the roots of Aconitum yesoense var. macroyesoense as well as 36 semi-synthetic C(20)-diterpenoid atisine-type alkaloid derivatives against A549 human lung carcinoma cells was examined. Ten acylated alkaloid derivatives, pseudokobusine 11-veratroate (9), 11-anisoate (12), 6,11-dianisoate (14), 11-p-nitrobenzoate (18), 11,15-di-p-nitrobenzoate (22), 11-cinnamate (25) and 11-m-trifluoromethylbenzoate (27), and kobusine 11-p-trifluoromethylbenzoate (35), 11-m-trifluoromethylbenzoate (36) and 11,15-di-p-nitrobenzoate (39), exhibited cytotoxic activity, and 11,15-dianisoylpseudokobusine (16) was found to be the most potent cytotoxic agent. Their IC(50) values against A549 cells ranged from 1.72 to 5.44 μM. In the occurrence of cytotoxic effects of atisine-type alkaloids, replacement by an acyl group at both C-11 and C-15 resulted in the enhancement of activity of the parent alkaloids compared to that from having hydroxy groups at this position, and the presence of a hydroxy group at the C-6 position was required for the cytotoxic effects. These acylated alkaloid derivatives inhibit cell growth through G1 arrest.

Diterpenoid alkaloids

The lasting attention that researchers have devoted to diterpenoid alkaloids is due to their various bioactivities and toxicities, structural complexity, and intriguing chemistry. From 1998 to the end of 2008, more than 300 new diterpenoid alkaloids were isolated from Nature. This review focuses on their structural relationships, and investigations into their chemical reactions, synthesis, and biological activities. A table that lists the names, plant sources, and structural types is given along with 363 references.

Diterpenoid Alkaloids from Delphinium majus

From the whole herbs of Delphinium majus, three new C(19)-diterpenoid alkaloids, majusines A-C (1-3), and six new C(20)-diterpenoid alkaloids, majusimines A-D (4-7) and majusidine A and B (8 and 9), have been isolated, together with 15 known compounds. The structures of compounds 1-9 were elucidated by spectroscopic data interpretation.

Inhibitory effects of diterpenoid alkaloids on the growth of A172 human malignant cells

The cytotoxicity against A172 human malignant glioma cells was examined for 14 alkaloids from the roots of Aconitum yesoense var. macroyesoense and of Aconitum japonicum and from the seeds of Delphinium elatum as well as for 25 semisynthetic derivatives. The major alkaloid constituents of A. yesoense var. macroyesoense, kobusine (2) and pseudokobusine (3), a minor alkaloid constituent of A. japonicum, aljesaconitine A (5), and six alkaloid derivatives, N-deethyldelcosine (10), N-deethyldelsoline (11), 12-benzoylluciculine (18), 12-anisoylluciculine (19), 6,11-dibenzoylpseudokobusine (28), and 6-veratroylpseudokobusine (29), had only very weak activity. Four acylated alkaloid derivatives, 12-acetylluciculine (23), 11-veratroylpseudokobusine (30), 11-(m-trifluoromethylbenzoyl)pseudokobusine (32), and 11-(m-trifluoromethylbenzoyl)kobusine (39), exhibited more potent activity, while pseudokobusine 11-cinnamoate (31), 11-anisoate (33), and 11-p-nitrobenzoate (34) were found to be the most potent cytotoxic agents.