The Alkaloid-Enriched Fraction of Pachysandra terminalis (Buxaceae) Shows Prominent Activity against Trypanosoma brucei rhodesiense

In the course of our studies on antiprotozoal natural products and following our recent discovery that certain aminosteroids and aminocycloartanoid compounds from Holarrhena africana A. DC. (Apocynaceae) and Buxus sempervirens L. (Buxaceae), respectively, are strong and selective antitrypanosomal agents, we have extended these studies to another plant, related to the latter-namely, Pachysandra terminalis Sieb. and Zucc. (Buxaceae). This species is known to contain aminosteroids similar to those of Holarrhena and structurally related to the aminocycloartanoids of Buxus. The dicholoromethane extract obtained from aerial parts of P. terminalis and, in particular, its alkaloid fraction obtained by acid-base partitioning showed prominent activity against Trypanosoma brucei rhodesiense (Tbr). Activity-guided fractionation along with extended UHPLC-(+)ESI QTOF MS analyses coupled with partial least squares (PLS) regression modelling relating the analytical profiles of various fractions with their bioactivity against Tbr highlighted eighteen constituents likely responsible for the antitrypanosomal activity. Detailed analysis of their (+)ESI mass spectral fragmentation allowed identification of four known constituents of P. terminalis as well as structural characterization of ten further amino-/amidosteroids not previously reported from this plant.

Three New Cytotoxic Steroidal Alkaloids from Sarcococca hookeriana

Three new steroidal alkaloids with an unusual 3α tigloylamide group, named sarchookloides A–C (1–3), were isolated along with four known compounds (4–7) from the roots of Sarcococca hookeriana. Their structures and relative configuration were elucidated on the basis of spectroscopic methods including MS, UV, IR, 1D, and 2D NMR data. The isolated compounds were evaluated for their cytotoxicity against five human cancer cell lines: Hela, A549, MCF-7, SW480, and CEM in vitro. All three amide substituted steroidal alkaloids exhibited significant cytotoxic activities with IC₅₀ values of 1.05–31.83 μM.

Antiinflammatory Steroidal Alkaloids from Sarcococca wallichii of Nepalese Origin

Bio-assay guided isolation from the plant Sarcococca wallichii Staph. yielded two new steroidal alkaloids: wallichimine A (1) and wallichimine B (2), and five known ones: sarcodinine (3), N-methylpachysamine A (4), alkaloid C (5), dictyophlebine (6), and sarcorine (7). The structures of the compounds were determined using mass spectrometry and NMR spectroscopy techniques. The immunomodulatory potential of compounds was evaluated on different parameters including production of intracellular reactive oxygen species (ROS), nitric oxide (NO) and on proinflammatory cytokine TNF-α. All compounds were found to be potent inhibitors of intracellular ROS produced from isolated neutrophils, except compound 5, which showed a moderate level of inhibition. Compounds 2 and 4 potently inhibited the production of NO (67.9% and 62.5% respectively). Compound 2 showed potent suppression on production of proinflammatory cytokine TNF-α (76.7%). Among all the tested compounds the new compound 2 was found to be the most potent immunosuppressive agent. This study shows that steroidal alkaloids could be lead compounds for anti-inflammatory drug discovery.

Rapid characterization and identification of steroidal alkaloids in Sarcococca coriacea using liquid chromatography coupled with electrospray ionization quadropole time-of-flight mass spectrometry

Rapid characterization of 23 pregnane-type steroidal alkaloids was studied using a positive ion electrospray ionization quadropole time-of-flight mass spectrometry (ESI-QqTOF-MS/MS) hybrid instrument. ESI-QqTOF-MS (positive ion mode) showed the presence of the protonated molecules [M+H](+) which through low-energy collision-induced dissociation tandem mass spectrometric (CID-MS/MS) analysis showed the characteristic loss of dimethylamine moiety [M+H-45](+) followed by the sequential lossess of attached substituents. Steroidal alkaloids having tigloyl or senecioyl group at C-3 produced diagnostic fragment ions at m/z 100 and 83. Our study also demonstrates the influence of unsaturation, and number and nature of substitutents on product ion abundance and fragment ions. Moreover, the generalization of the fragmentation pattern was linked with the structural features in steroidal skeleton. This strategy was successfully applied in LC-ESI-QqTOF-MS/MS analysis of Sarcococca coriacea extract to investigate and characterize pregnane-type steroidal alkaloids in complex mixture.

Cytotoxic steroids from Sarcococca saligna

Two new C₂₁-steroidal esters, sarsaligates A(1) and B(2), and two new steroidal alkaloids, sarsaligenines A(3) and B(4), together with four known compounds (sarcovagine, sarcorucinine, dimethylamino-3 β-pregnane-20-one, and β-sitosterol 5- 8, respectively), were isolated from the leaves and stems of Sarcococca saligna. The structures of compounds 1-4 were elucidated by NMR and MS spectroscopic analysis. Of the compounds tested, 5 and 6 were the most cytotoxic against the cell lines K562, SK-BR-3, and PANC-1, with IC₅₀ values in the range of 2.25-5.00 µM, while 3 and 4 selectively inhibited HL-60 cells with IC₅₀ values of 2.87 and 3.61 µM, respectively. Compounds 3-6 therefore deserve further evaluation of their cytotoxic potentials.

Bioactive steroidal alkaloids from Sarcococca hookeriana

Four new 5 alpha-pregnane-type steroidal alkaloids, hookerianamides L(1), M(2), N(3), and O(4), and a known N-formylchonemorphine (5) have been isolated by acid-base extraction of the dichloromethane extract of Sarcococca hookeriana. The structures of all compounds were determined with spectroscopic techniques and by comparison with literature data. All compounds displayed antileishmanial and antibacterial properties. Compounds 1, 4, and 5 were found to be more potent than standard pentamidine (IC (50) = 9.59 microg/mL) with respect to leishmanicidal activity. The minimum inhibitory concentration of most of the compounds against Bacillus subtilis, Streptococcus minor, and Streptococcus ferus was lower than that of the standard ampicillin.

Two new steroidal alkaloids from the roots of Sarcococca ruscifolia

Two new steroidal alkaloids, 20alpha-dimethylamino-2alpha-hydroxyl-3beta-tigloylamino-5alpha-pregnane (1) and Delta(16)-20alpha-dimethylamino-3beta,4alpha-diol-5alpha-pregnane (2), along with five known alkaloids, sarcovagine D (3), pachysamine G (4), pachysamine H (5), pachysamine A (6), and terminaline (20S)-20-(N,N-dimethylamino)-5alpha-pregn-3beta,4alpha-diol (7), were isolated from the roots of Sarcococca ruscifolia. Their structures were elucidated on the basis of NMR and MS data, and the relative stereochemistry of 1 was finally determined by X-ray crystallographic analysis.

Bioactive 5alpha-pregnane-type steroidal alkaloids from Sarcococca hookeriana

The bioassay-guided phytochemical investigation of Sarcococca hookeriana with respect to cholinesterase inhibitory properties has yielded two new 5alpha-pregnane-type steroidal alkaloids, hookerianamides J (1) and K (2), along with eight known compounds (3-10). The structures of 1 and 2 were elucidated by spectroscopic methods. These compounds displayed good to moderate activities in vitro against the enzymes acetylcholinesterase (IC 50 8.1-48.5 microM) and butyrylcholinesterase (IC 50 0.4-4.0 microM). Compounds 1-10 were also tested in vitro for their leishmanicidal activity against Leishmania major and for their antibacterial activities against Bacillus subtilis, Micrococcus luteus, Streptococcus faecalis, and Pseudomonas pallida.

Structure activity relationship studies on antileishmanial steroidal alkaloids from Sarcococca hookeriana

The search for antileishmanial constituents from the medicinal plant Sarcococca hookeriana (Buxaceae) of Nepalese origin has resulted in the isolation of 17 (1-17) active steroidal alkaloids. Compounds 1, 2, and 10 were subjected to derivatization and five chemically derived derivatives (1a, 2a, 10a, 10b, 10c) were also obtained. All these natural compounds and derivatives were found to have potent to mild antileishmanial properties. The IC(50) values were found to be in the range of 0.20-61.44 microg mL(-1) (IC(50) value of standard drug amphotericin B = 0.12 microg mL(-1)). The structure activity relationship indicated that the varieties of functionalities present in ring A of the steroidal alkaloids were found to play a characteristic role to increase the antileishmanial activity.

Cholinesterase Inhibiting and Antiplasmodial Steroidal Alkaloids from Sarcococca hookeriana

Bioguided phytochemical investigation of Sarcococca hookeriana with respect to the cholinesterase enzyme inhibitory assay yielded two new pregnane-type steriodal alkaloids hookerianamide H (1) and hookerianamide I (2), along with three known alkaloids N(a)-methylepipachysamine D (3), sarcovagine C (4) and dictyophlebine (5). Their structures were determined with the aid of extensive spectroscopic analysis. All compounds showed good inhibitory activities against the enzymes acetylcholinesterase (IC(50) 2.9-34.1 microM) and butyrylcholinesterase (IC(50) 0.3-3.6 microM). These compounds also showed moderate antiplasmodial activity (IC(50) 2.4-10.3 microM) against the Plasmodium falciparum chloroquine resistant W2 strain.

Studies on cardio-suppressant, vasodilator and tracheal relaxant effects ofSarcococca saligna

Sarcococca saligna is a shrub that is traditionally used for its medicinal properties in Pakistan. In this study we report the cardio-suppressant, vasodilator and tracheal relaxant activities of the aqueous-methanolic extract (Ss.Cr) of the plant. Ss.Cr, that tested positive for the presence of saponins, flavonoids, tannins, phenols, and alkaloids, exhibited a dose-dependent (0.3-5 mg/mL) negative inotropic and chronotropic effect on the isolated guinea-pig atrium which was resistant to atropine (1 microM) and aminophylline (10 microM) pretreatment. In rabbit thoracic aorta, Ss.Cr dose-dependently (0.1-3 mg/mL) relaxed the high K+ (80 mM) and phenylephrine (PE, 1 microM)-induced contractions, indicating a possible Ca++ channel blocking (CCB) effect. When tested against PE (1 microM) control peaks in normal Ca++ and Ca++-free Kreb's solution, Ss.Cr exhibited dose-dependent (0.1-3 mg/mL) inhibition, being more potent in relaxing the PE responses in Ca++-free Kreb's solution, thus indicating specific blockade of Ca++ release from the intracellular stores. Ss.Cr also relaxed the agonist-induced contractions in: a) rat aorta irrespective of the presence of endothelium or nitric oxide synthase inhibitor L-NAME and b) rabbit and guinea-pig tracheal strips. The data shows that Ss.Cr possesses possible Ca++ channel blocking activity which might be responsible for its observed cardio-suppressant, vasodilator and tracheal relaxant effects though more tests are required to confirm this Ca++ channel blocking effect.

[A pharmacology study of Cyclovirobuxinum D on curing myocardial ischemia induced by isoprenaline]

OBJECTIVE

To explore the pharmacology actions of Cyclovirobuxinum D (Cvb-D) for the myocardial ischemia and study its possible mechanism.

METHODS

The rats were given orally with Cvb-D 0.55 g/kg, 1.1 g/kg and 2.2 g/kg per day, for 21 days. The myocardial ischemia model were induced by isoprenaline. The rats ECG, serum CPK, LDH, FFA and myocardium tissue SOD, MDA level were detected.

RESULTS

Cvb-D could significantly reduce myocardial ischemia model induced by isoprenaline rats' sigmaJ of ECG, shorten ECG resume time, reduce serum FFA content, serum CPK, LDH activation, reduce cardiac tissue MDA content, raise the cardiac tissue SOD activation.

CONCLUSION

Cvb-D can decrease the release of FFA, CPK, LDH and improve the model rats' myocardium MDA, SOD level. It may be some of mechanisms of its anti-myocardial ischemia effect.

Cholinesterase inhibitory pregnane-type steroidal alkaloids from Sarcococca hookeriana

The bioassay-guided phytochemical investigation on Sarcococca hookeriana have resulted in the isolation of four new pregnane-type steriodal alkaloids: hookerianamide-D [(2'E,20S)-20-(N,N-formyl(methyl)amino)-3beta-(3',4'-dimethyl-2'-pentenamido)-5alpha-pregnane] (1), hookerianamide-E [(2'E,20S)-20-(N,N-dimethylamino)-3beta-(senecioylamino)-5alpha-pregn-14-en-2beta-O-acetate] (2), hookerianamide-F [(2'E,20S)-20-(N-methylamino)-3beta-(tigloylamino)-5alpha-pregn-2,14-dien-4-one] (3), and hookerianamide-G [(20S)-20-(N,N-dimethylamino)-3beta-(N-methylbenzamido)-5alpha-pregn-4beta-O-acetate] (4), along with five known alkaloids 5-9. Their structures were determined by spectroscopic analysis. These steroidal alkaloids and chemically derived derivatives of compound 5 have displayed varying degree of inhibitory activities against acetylcholinesterase and butyrylcholinesterase enzymes in a concentration-dependent fashion, with the IC(50) values ranging from 1.5 to 148.2 and 0.6 to 100.2 microM, respectively.

Cholinesterase inhibitory and spasmolytic potential of steroidal alkaloids

A new steroidal alkaloid, isosarcodine (1) along with four known bases, sarcorine (2), sarcodine (3), sarcocine (4) and alkaloid-C (5) were isolated from the MeOH extract of Sarcococca saligna. The structures of these alkaloids were identified by spectral data interpretation. These compounds were subjected to acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition studies, and were found to be noncompetitive inhibitors of AChE (Ki = 21.8, 90.3, 32.2, 16.0 and 50.0 microM, respectively) and uncompetitive or noncompetitive inhibitors of BChE (Ki = 8.3, 7.5, 15.6, 5.0 and 12.0 microM, respectively). The compounds (2-5) also showed dose-dependent spasmolytic activity in the rabbit jejunum intestinal preparations and also relaxed the high K+ (80 mM)-induced contraction, indicative of a calcium channel-blocking mechanism. Structure-activity relationship suggested that the nitrogen substituents at C-3 and/or C-20 of steroidal skeleton and the hydrophobic properties of the pregnane skeleton are the key structural features contributed to the inhibitory potency of these steroidal alkaloids against AChE and BChE.

3D-QSAR Studies on natural acetylcholinesterase inhibitors of Sarcococca saligna by comparative molecular field analysis (CoMFA)

We have derived a comprehensive structure-activity relationship (SAR) picture for a new series of natural acetylcholinesterase inhibitors isolated from Sarcococca saligna. A set of 32 previously isolated and tested pregnane-type steroidal alkaloids inhibitors were investigated with respect to their IC(50) values (pIC(50)) against the AChE enzyme in order to derive CoMFA models using atom-based alignment. A highly significant CoMFA model was obtained with r(2) value of 0.974. The q(2) (cross validation r(2)) value also confirms the statistical significance of our model.

Molecular Docking Studies of Natural Cholinesterase-Inhibiting Steroidal Alkaloids from Sarcococca saligna

Alkaloids isolated from Sarcococca saligna significantly inhibit acetyl- and butyrylcholinesterase enzyme, suggesting discovery of inhibitors for nervous-system disorders. Studying interactions with the active site of the AChE enzyme from Torpedo californica, we have identified hydrophobic interactions inside the aromatic gorge area as the major stabilizing factor in enzyme-inhibitor complexes of these alkaloids. Molecular Dynamics simulation of a predicted complex indicates that ligand binding does not extensively alter enzyme structure, but reduces flexibility at the gorge.

New steroidal alkaloids from Sarcococca saligna

Two new steroidal alkaloids, salonine-A [(20S)-20-(N,N-dimethylamino)-3beta-(tigloylamino)-5alpha-pregn-14-en-2beta,4beta-diol] (1), and salonine-B [(20S)-20-(N,N-dimethylamino)-3beta-methoxy-pregn-5,16-diene] (2), were isolated from the MeOH extract of Sarcococca saligna, along with a known base, alkaloid-C (3). Their structures were elucidated on the basis of spectroscopic methods. All three compounds were found to be cholinesterase inhibitors.

Antifeedant activity of some Sri Lankan plants

Twenty nine solvent extracts from twenty Sri Lankan plants were examined for antifeedant activity against the fourth instar larvae of Mexican bean beetle, Epilachna varivestis Muls., Coccinellidae. Extracts of Sarcococca brevifolia (Buxaceae), Strychnus nux vomica (Loganiaceae), Diploclisia glaucescens, Coscinium fenestratum (Menispermaceae), Syzygium caryophyllatum (Myrtaceae), Pittosporium zeylanicum (Pittosporaceae), Lasianthus gardneri (Rubiaceae), Ferronia limonia (Rutaceae) and Allophylus cobbe (Sapindaceae) have shown strong antifeedant activity.

New cholinesterase inhibiting steroidal alkaloids from the leaves of Sarcococca coriacea of Nepalese origin

From the leaves of Sarcococca coriacea two new steroidal alkaloids, epoxynepapakistamine-A [(20S)-20-(N-methylamino)-3beta-(tigloylamino)-5alpha-pregna-16alpha,17alpha-epoxy-2beta,4beta-di-O-acetate] (1), and epoxysarcovagenine-D [(20S)-20-(N-methylamino)-3beta-(tigloylamino)-5alpha-pregna-2-en-16alpha,17alpha-epoxy-4-one] (2), and two known compounds funtumafrine C [(20S)-20-(N,N-dimethylamino)-5alpha-pregna-3-one] (3) and N-methylfuntumine (4) were isolated. Their structures were elucidated on the basis of their spectral properties. The compounds 1, 3 and 4 were found to have cholinesterase inhibitory activity when tested for the inhibition of electric eel acetylcholinesterase and horse serum butyrylcholinesterase. They inhibited both enzymes in a concentration dependent fashion.