Strychnogucines a and B, Two New Antiplasmodial Bisindole Alkaloids from Strychnos Icaja

in Journal of Natural Products (2001), 64(1), 12-16

A reinvestigation of Strychnos icaja roots has resulted in the isolation of two tertiary quasi-symmetric bisindole alkaloids named strychnogucines A (1) and B (2). Their structures were identified by ... [more ▼]

A reinvestigation of Strychnos icaja roots has resulted in the isolation of two tertiary quasi-symmetric bisindole alkaloids named strychnogucines A (1) and B (2). Their structures were identified by means of spectroscopic data interpretation. Compound 2 was highly active in vitro and compound 1 moderately active against four strains of Plasmodium falciparum. Strychnogucine B (2) was more active against a chloroquine-resistant strain than against a chloroquine-sensitive one (best CI(50), 80 nM against the W2 strain). In addition, this compound showed a selective antiplasmodial activity with 25-180 times greater toxicity toward P. falciparum, relative to cultured human cancer cells (KB) or human fibroblasts (WI38). [less ▲]

Extraction of sesquiterpenic lactones with CO2 supercritical fluid and quantification of the extract by FTIR spectroscopy

Conference (2001)

Etude du mécanisme d’action d’alcaloides bisindoliques, isolés du Strychnos icaja, à potentialité anticancéreuse

Poster (2000, July)

Inhibition of Croton Oil-Induced Oedema in Mice Ear Skin by Capsular Polysaccharides from Cyanobacteria

in Naunyn-Schmiedeberg's Archives of Pharmacology (2000), 361(4), 460-4

The anti-inflammatory properties of hydrophilic extracts of the capsular polymers of twelve cyanobacterial strains belonging to the genera Phormidium and Nostoc from marine and terrestrial habitats were ... [more ▼]

The anti-inflammatory properties of hydrophilic extracts of the capsular polymers of twelve cyanobacterial strains belonging to the genera Phormidium and Nostoc from marine and terrestrial habitats were tested topically on croton oil-induced oedema in mice ear skin. The screening program identified several strains as producers of anti-inflammatory products (up to 56% inhibition of the oedema). The inhibition response was dose-dependent. The application of trichloroacetic acid-treated extracts reduced the oedema by about 60%. On the other hand, one of the strains enhanced the inflammatory response. Analysis of five of the extracts showed the presence of neutral sugars (from 34.3% to 47.1%, w/w), uronic acids (from 7.1% to 26.7%, w/w) and proteins (from 30.1% to 57.0%, w/w) in the crude polymer. Rhamnose, fucose, arabinose, xylose, mannose, glucose, galactose, galacturonic acid and glucuronic acid were detected as well as sulphate groups (from 9.6% to 21.5%, w/w of sugars). The main components found were glucose and mannose. [less ▲]

New Antimalarial and Cytotoxic Sungucine Derivatives from Strychnos Icaja Roots

in Planta Medica (2000), 66(3), 262-9

Reinvestigation of Strychnos icaja Baillon resulted in the isolation of vomicine, isostrychnine and of three new sungucine derivatives, named isosungucine (8), 18-hydroxy-sungucine (9) and 18-hydroxy ... [more ▼]

Reinvestigation of Strychnos icaja Baillon resulted in the isolation of vomicine, isostrychnine and of three new sungucine derivatives, named isosungucine (8), 18-hydroxy-sungucine (9) and 18-hydroxy-isosungucine (10). They were identified by detailed spectroscopic methods. The complete 1H- and 13C-NMR study of sungucine was also realized. Some of these compounds were highly active against Plasmodium falciparum in vitro and more particularly against the chloroquine-resistant strain. Compound 10 showed a selective antiplasmodial activity, with > 100-fold greater toxicity towards Plasmodium falciparum, relative to cultured human cancer cells (KB and HeLa lines) or fibroblasts (WI38). [less ▲]

Determination of Alpha-Solanine and Alpha-Chaconine in Potatoes by High-Performance Thin-Layer Chromatography/Densitometry

in Journal of AOAC International (2000), 83(6, Nov-Dec), 1468-73

A high-performance thin-layer chromatographic (HPTLC) method was used to determine the glycoalkaloids alpha-solanine and alpha-chaconine in potatoes. Alpha-solanine and alpha-chaconine are extracted from ... [more ▼]

A high-performance thin-layer chromatographic (HPTLC) method was used to determine the glycoalkaloids alpha-solanine and alpha-chaconine in potatoes. Alpha-solanine and alpha-chaconine are extracted from dehydrated potatoes with boiling methanol-acetic acid (95 + 5, v/v). The analytes are separated on a Silica Gel 60 F254 HPTLC plate by a saturated mixture of dichloromethane-methanol-water-concentrated ammonium hydroxide (70 + 30 + 4 + 0.4, v/v), which is used for vertical development of the plate up to a distance of 85 mm. For visualization, the plate is dipped 3 times into a modified Carr-Price reagent, 20% (w/v) antimony(III) chloride in acetic acid-dichloromethane (1 + 3, v/v), and subsequently heated on a hot plate at 105 degrees C for 5 min. The glycoalkaloids all appear as red chromatographic zones on a colorless background. Densitometric quantification is performed at 507 nm by reflectance scanning. After determination of the appropriate response function, the proposed method was validated. Good results with respect to linearity, accuracy, and precision were obtained in the concentration range studied. [less ▲]

Veronica officinalis L. et Veronica chamaedrys L. : étude des différences morphologiques et phytochimiques.

Poster (2000)

Anti-Inflammatory and Immunological Effects of Centaurea Cyanus Flower-Heads

in Journal of Ethnopharmacology (1999), 68(1-3), 235-41

Centaurea cyanus flower-heads are used in European phytotherapy for the treatment of minor ocular inflammations. Different pharmacological experiments (inhibition of carrageenan, zymosan and croton oil ... [more ▼]

Centaurea cyanus flower-heads are used in European phytotherapy for the treatment of minor ocular inflammations. Different pharmacological experiments (inhibition of carrageenan, zymosan and croton oil-induced oedemas, inhibition of plasma haemolytic activity, induction of anaphylatoxin activity) showed that polysaccharides extracted from C. cyanus flower-heads had anti-inflammatory properties and interfered with complement. Moreover, these polysaccharides were found to be mainly composed of galacturonic acid, arabinose, glucose, rhamnose and galactose. [less ▲]

Stimulation of DNA topoisomerase II – mediated DNA clivage by three DNA – intercalating plant alkaloids cryptolepine, matadine and serpentine

Poster (1999, July)

10'-Hydroxyusambarensine, a New Antimalarial Bisindole Alkaloid from the Roots of Strychnos Usambarensis

in Journal of Natural Products (1999), 62(4), 619-21

Reinvestigation of Strychnos usambarensis Gilg resulted in the isolation of a tertiary phenolic bisindole alkaloid, 10'-hydroxyusambarensine (1), which was identified by detailed spectroscopic methods ... [more ▼]

Reinvestigation of Strychnos usambarensis Gilg resulted in the isolation of a tertiary phenolic bisindole alkaloid, 10'-hydroxyusambarensine (1), which was identified by detailed spectroscopic methods. Compound 1 was moderately active against two strains of Plasmodium falciparum in vitro. [less ▲]