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.