New amide and diterpene alkaloids with anticholinesterase activity from Delphinium cyphoplectrum roots

BACKGROUND

The cholinergic hypothesis posits a robust correlation between the onset of Alzheimer's disease and a pronounced deficit in acetylcholine, a pivotal neurotransmitter crucial for the central cholinergic nervous system's function, pivotal for memory and learning. Diterpene alkaloids exhibit intricate and distinctive chemical structures that facilitate their passage through the blood-brain barrier. Moreover, their potent pharmacological attributes render them promising candidates for addressing central nervous system disorders.

OBJECTIVES

This investigation aims to scrutinize the alkaloidal composition of Delphinium cyphoplectrum (Ranunculaceae) roots, further exploring their anticholinesterase inhibitory activity and mode of inhibition.

METHOD

Innovative chromatography techniques were repetitively employed to purify the alkaloids. Acetylcholinesterase (AChE) inhibition assays were conducted using Ellman's tests. The mode of inhibition was meticulously characterized through Michaelis-Menten, and Lineweaver-Burk plots. Conducting molecular docking studies, we employed the AUTO DOCK 4.2 software package.

RESULTS

Eight alkaloids were identified including five C19-diterpene alkaloids (6,14,16,18-tetramethoxy-1,7,8-trihydroxy-4-methylaconitane (1), 6,16,18-trimethoxy-1,7,8,14-tetrahydroxy-4-methylaconitane (2), 6,8,16,18-tetramethoxy-1,7,14-trihydroxy-4-methylaconitane (3), 6,14,16-trimethoxy-1,7,8,18-tetrahydroxy-4-methylaconitane (4), and 14-O-acetyl-8,16-dimethoxy-1,6,7,18-tetrahydroxy-4-methylaconitane (5)), an epoxy C18-diterpene alkaloid (6,8,16-trimethoxy-1,7,14-trihydroxy-3,4-epoxyaconitane (6)), a known (pyrrolidin-2-one (7) and an undescribed amide alkaloid (1-(2'-hydroxylethylamine)-3,5,5,-trimethyl-1,5-dihydro-2H-pyrrol-2-one (8). All diterpene alkaloids underwent assessment for acetylcholinesterase (AChE) inhibition assay and displayed noteworthy AChE activity, surpassing that of the reference drug (with IC50 values of 13.7, 21.8, 23.4, 28.2, 40.4, and 23.9 for compounds 1-6, respectively, in comparison to 98.4 for Rivastigmine). Analysis of Michaelis-Menten and Lineweaver-Burk plots represents an uncompetitive mode of inhibition for compound 1 on AChE. Notably, computational docking simulations indicated that all diterpene alkaloids were accommodated within the same enzymatic cleft as the reference ligand, and displaying superior free binding energy values (from - 10.32 to -8.59 Kcal.mol-1) in contrast to Rivastigmine (-6.31 Kcal.mol-1).

CONCLUSION

The phytochemical analysis conducted on the roots of Delphinium cyphoplectrum yielded the identification of eight alkaloidal compounds including one C18-diterpene, five C19-diterpene, one pyrrolidine and one amide alkaloids. AChE inhibition assay and molecular simulations unveiled remarkable significant potency attributed to the C19-diterpene alkaloids by the order of 1 > 2 > 3,6 > 4 > 5. Presence of hydroxyl group on C-1, C-7, C-8, C-14, and C-18 increased the effect. The best in vitro activity was recorded for compound 1 able to bind to Asp72 in the narrow region of PAS, while interacting by pi-sigma with Phe330 at the hydrophobic region of the gorge involving the acyl and choline binding site. This observation underscores the substantial promise of this category of natural products in the realm of drug discovery for Alzheimer's Disease, offering a compelling avenue for further research and therapeutic development.

New diterpenoid alkaloids from Delphinium pachycentrum Hemsl

Six diterpenoid alkaloids, namely, pachycentine (1), deacetylswinanine A (2), siwanine A (3), tatsiensine (4), deacetyltatsiensine (5), and 6-deoxydeltamine (6), were isolated from a China-specific Delphinium plant (family Ranunculaceae), Delphinium pachycentrum Hemsl. Their structures were established via detailed spectroscopic analyses, including IR, HR-ESI-MS, 1D and 2D NMR techniques. Pachycentine (1) is a previously undescribed hetisine-type C20-diterpenoid alkaloid, and compounds 5 and 6 were synthetic intermediates newly identified as natural products. In addition, compounds 2-4 were isolated from this species for the first time. The chemotaxonomic significance of all the isolates was summarized. Moreover, the new compound was evaluated for its potential anti-inflammatory effect using LPS-stimulated RAW 264.7 macrophages.

Brunonianines A-C, C20-diterpenoid alkaloids with cyano group from Delphinium brunonianum Royle

Cyano tends to have better biological activity, but it is rarely reported in natural products, especially in the C20-diterpene alkaloids. Herein, three unprecedented C20-diterpenoid alkaloids, brunonianines A-C (1-3), possessing rare cyano functional group as well as an atisine backbone constructed from a phenethyl substituent and a tetrahydropyran ring, along with four C19-alkaloids (4-7) and one amide alkaloids (8), were isolated from the whole plant of Delphinium brunonianum Royle. Compounds 1-3 are also the first atisine type diterpenoid alkaloids with cyano group obtained from nature. The structures of the previously undescribed compounds were elucidated by HR-ESI-MS, 1D/2D NMR spectroscopic data and electronic circular dichroism calculations and single-crystal X-ray diffraction. Reasonable speculations have also been made regarding the biogenic synthetic pathways of compounds 1-3. In addition, the inhibitory activity of all compounds was also tested against four tumor lines: A549, Caco-2, H460 and Skov-3, where compound 2 (IC50 2.20 ± 0.21 μM) showed better inhibitory activity against Skov-3 cells than the hydroxycamptothecin. Using flow cytometry, cell staining, migration and invasion analysis, and Western blot, compound 2 was found to arrest cells in the G2/M phase and was able to effectively inhibit cell motility to achieve potent anti-tumor effects. In addition, compound 2 can effectively induce apoptosis by activating the Bax/Bcl-2/Caspase-3 signaling pathway.

Diterpenoid Alkaloids from Delphinium ajacis and Their Anti-inflammatory Activity

Three novel diterpenoid alkaloids, comprising two C19 -diterpenoid alkaloids (1 and 2) and one C20 -diterpenoid alkaloid (3), were isolated from Delphinium ajacis, alongside the six known compounds (4-9). Their structures were elucidated by spectroscopic methods (MS, UV, IR, 1D and 2D NMR) and chemical properties. Simultaneously, the anti-inflammatory properties of all compounds (1-9) was conducted, focusing on nitric oxide (NO) production in LPS-induced BV-2 cells. The results indicated compounds 1-3, 7, and 8 have potential anti-inflammatory activity.

Diterpenoid alkaloids from Delphinium trichophorum

Three new hetisine type C20-diterpenoid alkaloids, named as trichophorines A-C (1-3), were isolated from Delphinium trichophorum, together with nine known alkaloids (4-12). Their structures were elucidated on the basis of spectroscopic data (1D, 2D NMR, single-crystal X-ray, and HR-ESI-MS). All compounds were evaluated for the inhibitory activities against LPS induced NO production in RAW 264.7 macrophage cells, and none of them showed considerable inhibitory activity.

Kamaonensine A-G: Lycaconitine-type C19-diterpenoid alkaloids with anti-inflammatory activities from Delphinium kamaonense Huth

Delphinium kamaonense Huth is a sort of folkloric plant resource which is cultivated and planted with great ornamental and medicinal values. In this work, seven undescribed lycaconitine-type C19-diterpenoid alkaloids, especially a rare skeleton with -CH=N and N-oxide moieties, along with ten known compounds, were isolated from D. kamaonense, of which the structures were determined by various spectroscopic data, combined with calculated electronic circular dichroism (ECD) and single-crystal X-ray diffraction analysis. In vitro nitric oxide inhibitory activities assay of these compounds indicated that lycaconitine-type C19-diterpenoid alkaloids had significant anti-inflammatory inhibitory activities, with kamaonensine E being the most potent (0.9 ± 0.2 μM) stronger than positive (9.0 ± 1.3 μM). In the network pharmacology studies, binding three key targets mitogen-activated protein kinase 8 (MAPK8), mitogen-activated protein kinase 14 (MAPK14), and heat shock protein HSP 90-alpha (HSP90α), the anti-inflammatory mechanism might be related to MAPK signaling pathways. Furthermore, the molecular docking results revealed that the uncommon amides and methylenedioxy groups might be the most two promising pharmacophores for lycaconitine-type C19-diterpenoid alkaloids.

Polysubstituted Cyclopentene Benzamides and Dianthramide Alkaloids from Delphinium anthriscifolium Hance

Thirteen new benzamide alkaloids, delphiniumines A-M (1-13), together with one known analogue (14), were isolated from Delphinium anthriscifolium Hance. All of the structures were determined by spectroscopic and spectrometric analyses. Absolute configuration for 1 was established using experimental and calculated ECD data, as well as by X-ray crystallography analysis. Compound 1 possesses a previously undescribed polysubstituted cyclopentene carbon framework. Compound 2 was isolated as an artifact from 1 during the extraction process. Compound 7 is glycosylated with a β-D-glucose unit. Compound 13 bears a chlorine substituent. At a concentration of 10 μM, compounds 6, 8, and 10-12 suppressed LPS-induced NO production in RAW264.7 cells with inhibition rates ranging from 40.3% to 78.8%.

In vitro anti-Acanthamoeba activity of flavonoid glycosides isolated from Delphinium gracile, D. staphisagria, Consolida oliveriana and Aconitum napellus

Acanthamoeba spp. are widely distributed in the environment and cause serious infections in humans. Treatment of Acanthamoeba infections is very challenging and not always effective which requires the development of more efficient drugs against Acanthamoeba spp. The purpose of the present study was to test medicinal plants that may be useful in the treatment of Acanthamoeba spp. Here we evaluated the trophozoital and cysticidal activity of 13 flavonoid glycosides isolated from Delphinium gracile, D. staphisagria, Consolida oliveriana and from Aconitum napellus subsp. Lusitanicum against the amoeba Acanthamoeba castellanii. AlamarBlue Assay Reagent® was used to determine the activity against trophozoites of A. castellanii, and cytotoxic using Vero cells. Cysticidal activity was assessed on treated cysts by light microscopy using a Neubauer chamber to quantify cysts and trophozoites. Flavonoids 1, 2, 3 and 4 showed higher trophozoital activity and selectivity indexes than the reference drug chlorhexidine digluconate. In addition, flavonoid 2 showed 100% cysticidal activity at a concentration of 50 μm, lower than those of the reference drug and flavonoid 3 (100 μm). These results suggest that flavonoids 2 and 3 might be used for the development of novel therapeutic approaches against Acanthamoeba infections after satisfactory in vivo evaluations.

Antifungal Activity of New Diterpenoid Alkaloids Isolated by Different Chromatographic Methods from Delphinium peregrinum L. var. eriocarpum Boiss

This paper aimed to investigate the potential antifungal influences of new alkaloids from Delphinium peregrinum L. var. eriocarpum Boiss. New Diterpenoid alkaloids Delcarpum (1), Hydrodavisine (4) and known alkaloids Peregrine (2), Delphitisine (3) were isolated by different chromatographic methods from the aerial parts of D. Peregrinum eriocarpum Boiss, which grows in Syria. The structures of alkaloids were proposed based on 1D NMR spectroscopy 1H-NMR, 13C-NMR, DEPT-135, DEPT-90, 2D NMR spectroscopy DQF-COSY, HMQC, EI-Ms mass spectrum, and IR spectroscopic measurements. The antifungal activity of the isolated alkaloids was evaluated against different dermatophyte fungal isolates compared with fluconazole. In the case of Peregrine (2) the minimum inhibitory concentrations(MICs) recorded 128-256, 32-64, and 32 for Epidermophyton floccosum, Microsporum canis, and Trichophyton rubrum, respectively, compared to 32-64, 16, and 32 μg/mL in the case of fluconazole, respectively. The MICs recorded on application of the four alkaloids mixture were 64, 32, and 16 in the case of E. floccosum, M. canis, and T. rubrum, respectively, which were significantly lower than that measured for each of the individual alkaloid and were compatible for fluconazole. In conclusion, MICs of the tested alkaloids showed a variable potential effect on the investigated fungal isolates. Peregrine (2) was the most effective alkaloid, however, the application of the mixture of alkaloids induced significant synergistic activity that was more pronounced than the application of individual ones.

Phytochemical analysis and reappraisal of diuretic activity of Delphinium brunonianum Royle and its mode of action in experimental rats

The aim of this study was the evaluation of diuretic potential of Delphinium brunonianum. Acute diuretic effect in rats was evaluated 8 h after administration of various doses of crude extract, fractions and hydrochlorthiazide. While, prolonged effect of butanolic fraction was assessed after 7days of oral administration in rats. Thereafter, involvement of different pathways in diuretic activity was also appraised. Furthermore, polyphenolic contents in butanolic fraction were assessed using HPLC/UV-VIS technique. All doses of extract and fractions induced a prominent increase in urine and Na⁺ excretion with no effect on excretion of K⁺. Prior administration of indomethacin and atropine considerably avoided the diuretic effect of butanolic fraction. Regarding the quantitative chemical analysis the polyphenolic contents were recorded as 28.78 µg/mg. Thus results of present investigation suggested that Delphinium brunonianum possess remarkable diuretic potential.

The effect of Delphinium denudatum (Jadwar) on fatigue: A randomized double blind placebo-controlled clinical trial

OBJECTIVES

Fatigue is a common problem in modern-day life. The aim of this study was to evaluate the effect of Delphinium denudatum (Jadwar) on fatigue.

METHODS

This study was a randomized double-blind placebo-controlled clinical trial between healthy normal university students. In each group, participants were given one capsule of either WEACURE® (containing 500 mg of Jadwar root powder) or placebo for 15 consecutive days. Multidimensional Fatigue Inventory (MFI) questionnaire was used before and after the intervention to evaluate different aspects of fatigue.

RESULTS

A total number of 64 participants completed the study. Data analysis showed decrease in the scores of all five domains of fatigue in Jadwar group (13.31 ± 3.05-7.75 ± 2.66, 12.31 ± 3.55-7.63 ± 2.62, 12.22 ± 4.26-6.97 ± 2.06, 11.56 ± 4.21 to 7.28 ± 2.37, 12.91 ± 3.09-7.34 ± 2.13 in general fatigue, physical fatigue, reduced activity, reduced motivation, and mental fatigue domains, respectively) which was statistically significant (P value<0.0001). This situation was significantly superior to the placebo group. Prescribed dosage of WEACURE® capsule was well tolerated.

CONCLUSION

As a complementary tonic agent, Jadwar have a potential to reduce fatigue in normal population. However, objective evaluation of its anti-fatigue effect should be further evaluated.

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.

C18-Diterpenoid alkaloids from Delphinium anthriscifolium var. majus

Five new C₁₈-diterpenoid alkaloids, anthriscifoltines C-G (1-5), along with four known diterpenoid alkaloids anthriscifolcines C-F (6-9), were isolated from the extract of Delphinium anthriscifolium var. majus. Their structures were elucidated by extensive spectroscopic analyses (including 1D-, 2D-NMR, and HR-ESI-MS). Compounds 1-5 were also evaluated for their cytotoxic activity against MCF-7, HepG2, and H460 human cancer cell lines.

An agent-based model of cattle grazing toxic Geyer's larkspur

By killing cattle and otherwise complicating management, the many species of larkspur (Delphinium spp.) present a serious, intractable, and complex challenge to livestock grazing management in the western United States. Among the many obstacles to improving our understanding of cattle-larkspur dynamics has been the difficulty of testing different grazing management strategies in the field, as the risk of dead animals is too great. Agent-based models (ABMs) provide an effective method of testing alternate management strategies without risk to livestock. ABMs are especially useful for modeling complex systems such as livestock grazing management, and allow for realistic bottom-up encoding of cattle behavior. Here, we introduce a spatially-explicit, behavior-based ABM of cattle grazing in a pasture with a dangerous amount of Geyer's larkspur (D. geyeri). This model tests the role of herd cohesion and stocking density in larkspur intake, finds that both are key drivers of larkspur-induced toxicosis, and indicates that alteration of these factors within realistic bounds can mitigate risk. Crucially, the model points to herd cohesion, which has received little attention in the discipline, as playing an important role in lethal acute toxicosis. As the first ABM to model grazing behavior at realistic scales, this study also demonstrates the tremendous potential of ABMs to illuminate grazing management dynamics, including fundamental aspects of livestock behavior amidst ecological heterogeneity.

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 from Delphinium ajacis and Their Anti-RSV Activities

Five new diterpenoid alkaloids, ajacisines A-E (1-5), were isolated from Delphinium ajacis, along with seven known alkaloids (6-12). On the basis of their spectral data (IR, UV, HR-ESI-MS, 1D and 2D NMR) and chemical properties, the structures of compounds 1-12 were identified. All isolated compounds were evaluated for their in vitro antiviral activities against respiratory syncytial virus, and compounds 3-5 and 8 exhibited moderate to weak effects with IC₅₀ values of 75.2 ± 1.1, 35.1 ± 0.6, 10.1 ± 0.3, and 50.2 ± 0.5 µM, respectively.

Majusine D: A New C19-diterpenoid Alkaloid from Delphinium majus

A new C19-diterpenoid alkaloid, designated as majusine D (1), has been isolated from Delphinium majus W. T. Wang. The structure was elucidated by detailed NMR-spectroscopic studies.

Two New C18-Diterpenoid Alkaloids from Delphinium anthriscifolium

Two new C18-diterpenoid alkaloids, anthriscifoltine A (1) and anthriscifoltine B (2), along with three known diterpenoid alkaloids, deoxydelcorine (3), anthriscifolcine A (4) and anthriscifolcine G (5), were isolated from the whole herbs of Delphinium anthriscifolium var. majus. Their structures were elucidated by spectroscopic methods, including 1D, 2D NMR, and HR-ESI-MS.

Norditerpenoid alkaloids from Delphinium anthriscifolium

Two new norditerpenoid alkaloids with lycoctonine skeleton, anthriscifolcones A (1) and B (2), were isolated from the whole plant of Delphinium anthriscifolium var. Majus by extensive column chromatography. Their structures were established by IR, MS, (1)H NMR, (13)C NMR, and 2D NMR methods (including HSQC, (1)H-(1)H COSY, HMBC, and NOESY experiments).

Green synthesis of silver nanoparticles using Delphinium denudatum root extract exhibits antibacterial and mosquito larvicidal activities

Green synthesis of silver nanoparticles (AgNPs) using aqueous root extract of Delphinium denudatum (Dd) by reduction of Ag(+) ions from silver nitrate solution has been investigated. The synthesized DdAgNPs were characterized by using UV-Vis spectroscopy, X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM) and Fourier transform infrared spectroscopy (FTIR). The prepared DdAgNPs showed maximum absorbance at 416nm and particles were polydispersed in nature, spherical in shape and the size of the particle obtained was⩽85nm. The DdAgNPs exhibited antibacterial activity against Staphylococcus aureus ATCC 6538, Bacillus cereus NCIM 2106, Escherichia coli ATCC 8739 and Pseudomonas aeruginosa ATCC 9027. The DdAgNPs showed potent larvicidal activity against second instar larvae of dengue vector Aedes aegypti with a LC50 value of 9.6ppm.

New C20-diterpenoid alkaloids from Delphinium laxicymosum var pilostachyum

From the whole herb of Delphinium laxicymosum var pilostachyum, three new C20-diterpenoid alkaloids, laxipilostine, laxipilosdine, and laxipilosline (1-3), were isolated, together with fourteen known diterpenoid alkaloids. Their structures were determined by extensively interpretation of their spectroscopic data (1D- and 2D-NMR, MS, and IR).

Aconitum and delphinium diterpenoid alkaloids of local anesthetic activity: comparative QSAR analysis based on GA-MLRA/PLS and optimal descriptors approach

The duration of anesthesia (related to protein binding of a drug) and the onset time (determined by the pKa) are important characteristics in assessment of local anesthetic agents. They are known to be affected by a number of factors. Early studies of antiarrhythmic diterpenoid alkaloids from plants Aconitum and Delphinium suggested that they possess local anesthetic activity due to their ability to suppress sodium currents of excited membranes. In this study we utilized toxicity, duration, and onset of action as endpoints to construct Quantitative Structure-Activity Relationship (QSAR) models for the series of 34 diterpenoid alkaloids characterized by local anesthetic activity using genetic algorithm-based multiple linear regression analysis/partial least squares and simplified molecular input line entry system (SMILES)-based optimal descriptors approach. The developed QSAR models correctly reflected factors that determine three endpoints of interest. Toxicity correlates with descriptors describing partition and reactivity of compounds. The duration of anesthesia was encoded by the parameters defining the ability of a compound to bind at the receptor site. The size and number of H-bond acceptor atoms were found not to favor the speed of onset, while topographic electronic descriptor demonstrated strong positive effect on it. SMILES-based optimal descriptors approach resulted in overall improvement of models. This approach was shown to be more sensitive to structural peculiarities of molecules than regression methods. The results clearly indicate that obtained QSARs are able to provide distinct rationales for compounds optimization with respect to particular endpoint.

Diterpenoid alkaloids and flavonoids from Delphinium trichophorum

Five hetisane-type C20-diterpenoid alkaloids, trichodelphinines A-E, one delnudine-type C20-diterpenoid alkaloid, trichodelphinine F and three known flavonoids, quercetin, quercetin 3-O-β-D-glucopyranoside, and quercetin 3-O-β-D-glucopyranoside-7-O-α-L-arabinopyranoside, were isolated from whole plants of Delphinium trichophorum Franch. Their structures were elucidated on the basis of extensive spectroscopic analysis, including HSQC, HMBC, (1)H-(1)H COSY, NOESY and X-ray crystallographic analysis, and from chemical evidence. The cytotoxic activities of the diterpenoid alkaloids were evaluated using the MTT method, and the IC50 values of their cytotoxicity against A549 cancer cells ranged from 12.03 to 52.79 μM.

p-Hydroxybenzoyl-glucose is a zwitter donor for the biosynthesis of 7-polyacylated anthocyanin in Delphinium

The blue color of delphinium (Delphinium grandiflorum) flowers is produced by two 7-polyacylated anthocyanins, violdelphin and cyanodelphin. Violdelphin is derived from the chromophore delphinidin that has been modified at the 7-position by Glc and p-hydroxybenzoic acid (pHBA) molecules. Modification of violdelphin by linear conjugation of Glc and pHBA molecules to a Glc moiety at the 7-position produces cyanodelphin. We recently showed that anthocyanin 7-O-glucosylation in delphinium is catalyzed by the acyl-Glc-dependent anthocyanin glucosyltransferase (AAGT). Here, we sought to answer the question of which enzyme activities are necessary for catalyzing the transfer of Glc and pHBA moieties to 7-glucosylated anthocyanin. We found that these transfers were catalyzed by enzymes that use p-hydroxybenzoyl-Glc (pHBG) as a bifunctional acyl and glucosyl donor. In addition, we determined that violdelphin is synthesized via step-by-step enzymatic reactions catalyzed by two enzymes that use pHBG as an acyl or glucosyl donor. We also isolated a cDNA encoding a protein that has the potential for p-hydroxybenzoylation activity and two AAGT cDNAs that encode a protein capable of adding Glc to delphinidin 3-O-rutinoside-7-O-(6-O-[p-hydroxybenzoyl]-glucoside) to form violdelphin.

Norditerpenoid alkaloids from Delphinium flexuosum Bieb

Delphiniflexine, a new norditerpenoid alkaloid, together with the three known norditerpenoid alkaloids methyllycaconitine, ajadine, and acoseptrigenine were isolated from the aerial parts of Delphinium flexuosum. The structure of delphiniflexine was established on the basis of 1H, 13C, DEPT, homonuclear 1H COSY, NOESY, HSQC, and HMBC NMR studies.

Structure-cardiac activity relationship of C19-diterpenoid alkaloids

Thirty three C19-diterpenoid alkaloids, twenty-two prepared from known C19-diterpenoid alkaloids and eleven isolated from Aconitum and Delphinium spp. were evaluated for their cardiac activity in the isolated bullfrog heart assay. Among them, eleven compounds exhibited cardiac activity, with average rate of amplitude increase in the range of 16-118%. Compound 7, mesaconine (17), hypaconine (25), and beiwutinine (26) exhibited strong cardiac activities relative to the reference drug. The structure-activity relationship data acquired indicated that an alpha-hydroxyl group at C-15, a hydroxyl group at C-8, an alpha-methoxyl or hydroxyl group at C-1, and a secondary amine or N-methyl group in ring A are important structure features necessary for the cardiac activities of the aconitine-type C19-diterpenoid alkaloids without any ester groups. In addition, an alpha-hydroxyl group at C-3 is also helpful for the cardiac activity of these alkaloids.

In vitro and in vivo trypanocidal activity of flavonoids from Delphinium staphisagria against Chagas disease

The in vitro and in vivo trypanocidal activities of nine flavonoids (1-9) isolated from the aerial parts of Delphinium staphisagria have been studied in both the acute and chronic phases of Chagas disease. The antiproliferative activity of these substances against Trypanosoma cruzi (epimastigote, amastigote, and trypomastigote forms) in some cases exhibited more potent antitrypanosomatid activity and lower toxicity than the reference drug, benznidazole. Studies in vitro using ultrastructural analysis together with metabolism-excretion studies were also performed in order to identify the possible action mechanism of the compounds tested. Alterations mainly at the level of the mitochondria may explain metabolic changes in succinate and acetate production, perhaps due to the disturbance of the enzymes involved in sugar metabolism within the mitochondrion. In vivo studies provided results consistent with those observed in vitro. No signs of toxicity were detected in mice treated with the flavonoids tested, and the parasitic charge was significantly lower than in the control assay with benznidazole. The effects of these compounds were also demonstrated with the change in the anti-T. cruzi antibody levels during the chronic stage.

Two new C20-diterpenoid alkaloids from Delphinium anthriscifolium var. savatieri

Further phytochemical investigation of the whole herb of Delphinium anthriscifolium var. savatieri resulted in the isolation of two new C20-diterpenoid alkaloids, anthriscifolmines I (1) and J (2). The structures of the two new alkaloids were elucidated on the basis of spectral data, including 2D NMR and HRESIMS.

C19-Diterpenoid alkaloids from Delphinium umbrosum

Three new C(19)-diterpenoid alkaloids, umbrosumines A-C (1-3), and 11 known compounds (4-14) were isolated from the roots of Delphinium umbrosum. Their structures were elucidated on the basis of the spectroscopic data interpretation.

Anticonvulsant activity of DNS II fraction in the acute seizure models

AIM OF THE STUDY

Delphinium nordhagenii belongs to family Ranunculaceae, it is widely found in tropical areas of Pakistan. Other species of Delphinium are reported as anticonvulsant and are traditionally used in the treatment of epilepsy. Delphinium nordhagenii is used by local healer in Pakistan but never used for scientific investigation as anticonvulsant. Thus, Delphinium nordhagenii was subjected to bioassay-guided fractionation and the most active fraction, i.e. DNS II acetone was chosen for further testing in the acute seizure models of epilepsy to study the antiepileptic potential in male mice.

MATERIALS AND METHODS

Different doses (60, 65 and 70mg/kg, i.p.) of DNS II acetone fraction of Delphinium nordhagenii was administered 30min prior the chemoconvulsant's injection in the male mice. Convulsive doses of chemoconvulsants (pentylenetetrazole 90mg/kg, s.c. and picrotoxin 3.15mg/kg, s.c.) were used. The mice were observed 45-90min for the presence of seizures. Moreover, four different doses of DNS II (60, 65, 70 and 100mg/kg, i.p.) were tested in the MES test.

RESULTS

The DNS II acetone fraction of Delphinium nordhagenii has exhibited the anticonvulsant actions by preventing the seizures against PTZ- and picrotoxin-induced seizure as well as 100% seizure protection in MES test. The results are comparable with standard AEDs (diazepam 7.5mg/kg, i.p. and phenytoin 20mg/kg, i.p.).

CONCLUSIONS

These findings suggest that the Delphinium nordhagenii possesses the anticonvulsant activity. Further analysis is needed to confirm the structure and target the extended activity profile.

Acylated flavonol tetraglycosides from Delphinium gracile

An ethanol extract of the aerial parts of Delphinium gracile DC. yielded five flavonol glycosides quercetin-3-O-{[beta-d-xylopyranosyl (1-->3)-4-O-(E-p-caffeoyl)-alpha-l-rhamnopyranosyl (1-->6)][beta-d-glucopyranosyl (1-->2)]}-beta-d-glucopyranoside (1), quercetin-3-O-{[beta-d-xylopyranosyl (1-->3)-4-O-(E-p-coumaroyl)-alpha-l-rhamnopyranosyl (1-->6)][beta-d-glucopyranosyl (1-->2)]}-beta-d-glucopyranoside (2), quercetin-3-O-{[beta-d-xylopyranosyl (1-->3)-4-O-(Z-p-coumaroyl)-alpha-l-rhamnopyranosyl (1-->6)][beta-d-glucopyranosyl (1-->2)]}-beta-d-glucopyranoside (3), kaempferol-3-O-{[beta-d-glucopyranosyl (1-->3)-4-O-(E-p-coumaroyl)-alpha-l-rhamnopyranosyl (1-->6)][beta-d-glucopyranoside-7-O-(4-O-acetyl)-alpha-l-rhamnopyranoside (4) kaempferol-3-O-{[beta-d-glucopyranosyl (1-->3)-4-O-(E-p-coumaroyl)-alpha-l-rhamnopyranosyl (1-->6)][beta-d-glucopyranoside-7-O-(4-O-acetyl)-alpha-l-rhamnopyranoside (5) in addition to 4-(beta-d-glucopyranosyloxy)-6-methyl-2H-pyran-2-one (6) and rutin. Structures were elucidated by spectroscopic methods.

Synergy effect of sodium acetate and glycosidically bound volatiles on the release of volatile compounds from the unscented cut flower (Delphinium elatum L. "Blue Bird")

Many modern floricultural varieties have lost their scent during traditional breeding programs. The factors that result in the nonscent emission of some cut flowers remain unclear. The objective of this study was to investigate whether the nonscent emission is due to one of the factors, the lack of suitable substrates (or precursors of scent compounds). Using solid-phase microextraction and dynamic headspace volatile sampling techniques, the supplement of nonvolatile compounds such as 2-coumaric acid glucoside to the unscented cut flower such as Delphinium elatum L. "Blue Bird" enhanced the emission of scent from the flower, which was sufficient for detection by the human olfaction. Interestingly, compared with feeding with each compound, the combination of sodium acetate and 2-coumaric acid glucoside showed the synergy effect on enhancement of coumarin, a cherry leaf-like scent emission from the flower, which is due to one of factors that sodium acetate enhanced the activity of beta-glucosidase being involved in the formation of the scent compound. These results suggest that some enzymes responsible for the formation of floral scents indeed occur in the unscented flowers such as Delphinium elatum L. "Blue Bird", and the non- or low-scent emission of the flowers are due to the lack of suitable substrates.

[Experimental study of the mechanisms of the tissue repair activity of complex and individual agents isolated from Delphinium elatum]

It is demonstrated in experiment that the entire complex and individual agents isolated from the above-ground part of bee larkspur Delphinium elatum stimulate the reparative regeneration of skin in white mongrel mice. The maximum activity was exhibited by the alkaloid fraction of Delphinium elatum.

HPLC-MS analysis of toxic norditerpenoid alkaloids: refinement of toxicity assessment of low larkspurs (Delphinium spp.)

INTRODUCTION

The low larkspurs (Delphinium nuttallianum and D. andersonii) are two toxic plant species that are often fatally ingested by cattle on western USA rangelands. To assess the potential toxicity of the plants, methods are needed to identify and quantify the toxic N-methylsuccinimidoanthranoyllycacontine type alkaloids in the plant.

OBJECTIVE

To compare normal-phase and reverse-phase HPLC-MS methods of analysis for detection and identification of toxic alkaloids in two species of toxic larkspur plants and to define the toxic alkaloids found in Delphinium nuttallianum and D. andersonii collected from several sites in the western USA.

RESULTS

The major toxic alkaloids found in the low larkspurs included methyllycaconitine, nudicauline, 14-deacetylnudicauline and geyerline. Other toxic alkaloids detected at lower concentrations included 16-deacetylgeyerline, grandiflorine, bearline, 14-acetylbearline, barbinine, 16-demethylnudicauline and three additional isomers of bearline. Total toxic alkaloid concentrations ranged from 0.72 mg/g (d.w.) to 7.02 mg/g determined by reverse-phase HPLC-MS.

CONCLUSION

The low larkspurs contain a number of toxic alkaloids in addition to the alkaloid methyllycaconitine that need to be assessed when considering the toxicity of the plant. Both normal-phase and reverse-phase HPLC methods are adequate to detect and quantify the alkaloids. The reverse-phase separation may be preferred due to readily available columns, reduced solvent use and simplicity of the electrospray ionisation source.

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.

[Evaluation of anti-inflammatory activity of extracts from Siberian plants]

Experimental investigations have shown that water-alcohol extracts from plants containing alkaloids (Aconitum baikalense, Aconitum septentrionale, Delphinium elatum L., Conium maculatum) and salicylic acid (Filipendula ulmaria, Salix viminalis, Fragaria vesca, Rubus idaeus) inhibited the development of main symptoms of inflammation, viz. exudation, pain, fever, to the same extent as non-steroidal anti-inflammatory agents. The substances studied in this work may be used to develop new efficient pharmacological preparations for the treatment of different inflammatory conditions associated with severe pain syndrome.

[Study on chemical constituents from Delphinium honanense var. piliteram]

OBJECTIVE

To study the chemical constituents from Delphinium honanense var. piliteram.

METHOD

The constituents were isolated and purified with chromatographic methods, identified by NMR, MS and IR.

RESULT

Six compounds were isolated and elucidated as siwanine E (1), isoatisine (2), 12-epi-napelline (3), acontine (4), ajadelphinine (5) and beta-sitosterol (6).

CONCLUSION

Compounds 1-6 are all isolated from the plant for the first time.

Dietary agents for chemoprevention of prostate cancer

Prostate cancer (CaP) is the leading cause of cancer-related deaths in American men, responsible for over 29,000 deaths in the year 2007. Chemoprevention is a plausible and cost-effective approach to reduce cancer morbidity and mortality through inhibition of precancerous events before the occurrence of clinical disease. Indeed, CaP is an ideal candidate disease for chemopreventive intervention as it is typically diagnosed in the elderly population with a relatively slower rate of growth and progression. The potential of dietary substances to act as chemopreventive agents against CaP is increasingly appreciated. Further, epidemiological studies have identified significant correlations between CaP incidence and dietary habits. It is hoped that, combining the knowledge based on agents with targets, we will be able to build an armamentarium of naturally occurring chemopreventive substances that could prevent or slow down the development and progression of CaP. In this review, we have summarized the findings from clinical and preclinical studies on dietary agents including green tea, pomegranate, lupeol, fisetin, and delphinidin that are currently being investigated in our laboratory for their chemopreventive potential against CaP.

[Study on chemical constituents of Delphinium grandiflorum]

OBJECTIVE

To study the chemical constituents isolated from the roots of Delphinium grandiflorum L. var. leiocarpum W. T. Wang.

METHODS

The constituents were isolated and purified by various chromatographic methods and their structures were identified by spectral analysis.

RESULTS

Five known diterpenoid alkaloids lycoctonine (I), methyllycaconitine (II), delsemine A (III), delavaine A (IV) , delajadine (V) and the other two beta-sitosterol (VI), plamitic acid (VII) were isolated from the roots of Delphinium grandiflorum.

CONCLUSION

All these compounds are isolated from this plant for the first time.

Aconitum and Delphinium sp. alkaloids as antagonist modulators of voltage-gated Na+ channels. AM1/DFT electronic structure investigations and QSAR studies

Early pharmacological studies of Aconitum and Delphinium sp. alkaloids suggested that these neurotoxins act at site 2 of voltage-gated Na(+) channel and allosterically modulate its function. Understanding structural requirements for these compounds to exhibit binding activity at voltage-gated Na(+) channel has been important in various fields. This paper reports quantum-chemical studies and quantitative structure-activity relationships (QSARs) based on a total of 65 natural alkaloids from two plant species, which includes both blockers and openers of sodium ion channel. A series of 18 antagonist alkaloids (9 blockers and 9 openers) have been studied using AM1 and DFT computational methods in order to reveal their structure-activity (structure-toxicity) relationship at electronic level. An examination of frontier orbitals obtained for ground and protonated forms of the compounds revealed that HOMOs and LUMOs were mainly represented by nitrogen atom and benzyl/benzoylester orbitals with -OH and -OCOCH(3) contributions. The results obtained from this research have confirmed the experimental findings suggesting that neurotoxins acting at type 2 receptor site of voltage-dependent sodium channel are activators and blockers with common structural features and differ only in efficacy. The energetic tendency of HOMO-LUMO energy gap can probably distinguish activators and blockers that have been observed. Genetic Algorithm with Multiple Linear Regression Analysis (GA-MLRA) technique was also applied for the generation of three-descriptor QSAR models for the set of 65 blockers. Additionally to the computational studies, the HOMO-LUMO gap descriptor in each obtained QSAR model has confirmed the crucial role of charge transfer in receptor-ligand interactions. A number of other descriptors such as logP, I(BEG), nNH2, nHDon, nCO have been selected as complementary ones to LUMO and their role in activity alteration has also been discussed.

Diterpenoid alkaloids from Delphinium gracile

Two highly oxygenated hetisine-type diterpenoid alkaloids, delphigraciline (1), 14-hydroxyhetisinone N-oxide (2), and the norditerpenoid alkaloid 8-methoxykarakoline (3), were isolated from a neutral extract of Delphinium gracile. Their structures were elucidated on the basis of spectroscopic data and by comparison with previously reported spectroscopic data of similar alkaloids. Their antiparasitic and insecticidal activities are also discussed.

New C18-diterpenoid alkaloids from Delphinium anthriscifolium var. savatieri

Five new C18-diterpenoid alkaloids, anthriscifolcines A (1), B (2), C (3), D (4), and E (5), together with a known C19-diterpenoid alkaloid delcorine (6), were isolated from the whole herb of Delphinium anthriscifolium var. savatieri. The structures of these new alkaloids were established on the basis of spectral data (1D- and 2D-NMR, HR-ESI-MS).

New diterpenoid alkaloids from the roots of Delphinium tiantaishanense

Four new diterpenoid alkaloids: tiantaishansine (1), tiantaishannine (2), tiantaishanmine (3), and tiantaishandine (4) have been isolated from the roots of Delphinium tiantaishan. Their structures were elucidated by chemical evidence and spectral analyses, including ESI-MS, HR-EI-MS, 1D- and 2D-NMR.

Norditerpenoid alkaloids from Delphinium nordhagenii

Three new norditerpenoid alkaloids, nordhagenine A (1), nordhagenine B (2), and nordhagenine C (3), along with a known alkaloid, lycoctonine, were isolated from the aerial parts of Delphinium nordhagenii. The structures of the new compounds 1 and 2 were also deduced on the basis of single-crystal X-ray diffraction studies.

Enantioselective approach to the hetisine alkaloids. Synthesis of the 3-methyl-1-aza-tricyclo[5.2.1.0(3,8)]decane core via intramolecular dipolar cycloaddition

[structure: see text]. An efficient, enantioselective approach to the hetisine class of the C(20)-diterpenoid alkaloids is described. The strategy involves an intramolecular oxidopyridinium dipolar cycloaddition as the key transformation, in which simultaneous formation of the C5-C6 and C10-C20 bonds in the 3-methyl-1-aza-tricyclo[5.2.1.0(3,8)]decane core of the hetisine alkaloids is effected.

C20-diterpenoid alkaloids from Delphinium trifoliolatum

Three new C20-diterpenoid alkaloids, trifoliolasines D-F (1-3), were isolated from the aerial parts of Delphinium trifoliolatum, and their structures were determined by the interpretation of spectroscopic data and by the single-crystal X-ray crystallographic analysis of 1.

Uraline, a New Norditerpenoid Alkaloid from Aerial Parts of Delphinium uralense Nevski

Uraline, a new norditerpenoid alkaloid, was isolated from aerial parts of Delphinium uralense. The structure of 1alpha,7,8-trihydroxy-6beta,14alpha,16beta-trimethoxy-18-N-(2-methyl)succinylanthranoyloxyaconane was ascribed to the new compound on the basis of 1H and 13C NMR, IR, and mass spectra. The known alkaloids methyllycaconitine and delcorine were also isolated from the plant.

Dianthramide glucosides from tissue cell cultures of Delphinium staphisagria L

Tissue cell cultures of Delphinium staphisagria L. produced three dianthramide glucosides N-(2'-beta-glucopyranosylsalicyl)-5-hydroxyanthranilic acid methyl ester, N-(2'-beta-glucopyranosyl-5'-methoxysalicyl)-5-hydroxyanthranilic acid methyl ester and N-(2'-beta-glucopyranosyl-5'-hydroxysalicyl)-5-hydroxy-6-methoxyanthranilic acid methyl ester, together with known methyl esters of N-salicylanthranilic acid and N-(2'-beta-glucopyranosyl-5'-hydroxysalicyl)-5-hydroxyanthranilic acid. Structures of the glucosides were established by MS, 1-D and 2-D NMR techniques.

Diterpenoid alkaloids from the roots of Delphinium scabriflorum

Chemical investigation of the CHCl(3) extracts from the roots of Delphinium scabriflorum has resulted in the isolation of a new diterpenoid alkaloid, 13-(2-methylbutyryl)azitine (1), along with 11 known alkaloids, delbine (2), 14-deacetyl-14-isobutyrylajadine (3), methyllycaconitine (4), 14-deacetylnudicauline (5), delectinine (6), deltatsine (7), dictysine (8), geyerline (9), ajacine (10), lycoctonine (11), and delcosine (12). The structure of 1 was determined by spectroscopic data interpretation. Complete NMR data for alkaloids 2-8 are presented. Some earlier (13)C NMR assignments made for alkaloids 4-7 were revised.

Alkaloids from Delphinium pentagynum

Aerial parts of a collection of Delphinium pentagynum Lam. from Niebla, Southern Spain, furnished one diterpene alkaloid, 2-dehydrodeacetylheterophylloidine, two norditerpene alkaloids, 14-demethyl-14-isobutyrylanhweidelphinine and 14-demethyl-14-acetylanhweidelphinine, the known alkaloids 14-deacetylnudicauline, methyllycaconitine, 14-deacetyl-14-isobutyrylnudicauline, 14-acetylbrowniine, browniine, delcosine, lycoctonine, 18-methoxygadesine, neoline, karakoline and the aporphine alkaloid magnoflorine. Structures of the alkaloids were established by MS, 1D and 2-D NMR techniques.