Do metal-rich plants deter herbivores? A field test of the defence hypothesis.

Some plant species growing on metalliferous soils are able to accumulate heavy metals in their shoots up to very high concentrations, but the selective advantage of this behaviour is still unknown. The most popular hypothesis, that metals protect plants against herbivores, has been tested several times in laboratory conditions, with contradictory results. We carried out the first large-scale test of the defence hypothesis in eight natural populations of the model Zn hyperaccumulator Thlaspi caerulescens J.

Alkaloids and amides from Triclisia sacleuxii.

A new alkaloid, named gasabiimine (1), together with four known bisbenzyltetrahydroisoquinoline alkaloids (phaeanthine, 1,2-dehydroapateline, N-methylapateline, O-methylcocsoline) has been isolated from the roots of Triclisia sacleuxii. The structure of the new alkaloid was elucidated by spectroscopic data analysis.

Isolation and antimicrobial activity of two phenolic compounds from Pulicaria odora L.

The essential oil of Pulicaria odora, a Moroccan medicinal plant; was analyzed by GC-MS, and subjected to column chromatography on silica gel. Two major constituents were isolated and identified as 2-isopropyl-4-methylphenol (1) and isobutyric acid 2-isopropyl-4-methylphenylester (2), by analysis of spectroscopic data (MS, 1H NMR, 13C NMR, DEPT, COSY, HMQC and HMBC experiments). The isolated compounds are reported for the first time from Pulicaria genus.

Polysaccharides extracted from the leaves of Plantago palmata Hook.f. induce nitric oxide and tumor necrosis factor-alpha production by interferon-gamma-activated macrophages.

Ethnopharmacological data from eastern African traditional uses of Plantago palmata leaves suggest that some therapeutical activities could be dependent on their content in polysaccharides (PS). To further investigate immunomodulatory properties of these PS, they were extracted in water from leaves by maceration either at (i) 50 degrees C without filtration (PS50); (ii) 50 degrees C and filtration (PS50F); (iii) 100 degrees C, without filtration (PS100); or 100 degrees C and filtration (PS100F). The extract PS50 was further fractionated by high performance liquid chromatography (gel permeation chromatography) in three fractions namely F1, F2, and F3.

Cytotoxic constituents from Plumbago zeylanica.

The bioassay-guided fractionation of the dichloromethane extract of aerial parts of Plumbago zeylanica led to the isolation of beta-sitosterol, beta-sitosteryl-3beta-glucopyranoside, beta-sitosteryl-3beta-glucopyranoside-6'-O-palmitate (1), lupenone, lupeol acetate, plumbagin and trilinolein. Compound 1 showed cytotoxic activity against MCF7 and Bowes cancer cell lines (IC50 113 microM and 152 microM, respectively), beta-sitosterol inhibited Bowes cell growth (IC50 36.5 microM) and plumbagin was cytotoxic against MCF7 and Bowes cells (IC50 1.

Two triacylated and tetraglucosylated anthocyanins from Ipomoea asarifolia flowers.

Two triacylated and tetraglucosylated anthocyanins derived from cyanidin were isolated from the flowers of Ipomoea asarifolia and their structures elucidated using chemical, GC, MS and NMR methods (1H and 13C, TOCSY-1D, DQF-COSY, DIFFNOE and HMBC). These complex pigments were found to consist of cyanidin 3-O-[2-O-(6-O-E-caffeoyl-beta-D-glucopyranosyl)]-[6-O-[4-O-(6-O-E-3,5-dihydroxycinnamoyl-beta-D-glucopyranosyl)-E-caffeoyl]-beta-D-glucopyranosyl]-5-O-beta-D-glucopyranoside and cyanidin 3-O-[2-O-(6-O-E-p-coumaroyl-beta-D-glucopyranosyl)]-[6-O-[4-O-(6-O-E-p-coumaroyl-beta-D-glucopyranosyl)-E-caffeoyl]-beta-D-glucopyranosyl]-5-O-beta-D-glucopyranoside.

Taxanes in Taxus baccata pollen: cardiotoxicity and/or allergenicity?

Diterpenic alkaloids belonging to taxine (yield: 0.18 % dry weight) and taxoids (paclitaxel, baccatine III and 10-deacetylbaccatine III, cumulated yield: 0.004 % dry weight) were isolated from Taxus baccata L.

Alkamides from Artemisia dracunculus.

From the aerial parts of Artemisia dracunculus, one known alkamide, pellitorine, two new alkamides neopellitorine A and neopellitorine B, and one known coumarin herniarine were isolated. Structures were elucidated by means of UV, IR, MS, 1H and 13C NMR. These compounds showed insecticidal activity against Sitophilus oryzae and Rhyzopertha dominica at 200 microg/ml concentrations.

Effects of antiinflammatory triterpenes isolated from Leptadenia hastata latex on keratinocyte proliferation.

Several triterpenes isolated from Leptadenia hastata latex were tested for their anti-inflammatory activity. Lupeol (1), its acetate (2) and palmitate (3) esters were found to be the main antiinflammatory constituents in the croton oil-induced ear oedema test. Furthermore, lupeol hemisuccinate (4), synthesized from lupeol, exhibited a higher activity than lupeol in the test.

Antisickling activity of sodium cromoglicate in sickle-cell disease.

Two groups of patients with sickle-cell disease were given a single dose of sodium cromoglicate by inhalation or nasal route. The striking decrease in sickle cells after treatment by both routes lends support to the role of sodium cromoglicate in sickle-cell disease treatment.

High-performance thin-layer chromatographic determination of six major ginsenosides in Panax ginseng.

A densitometric determination of six major ginsenosides in Panax ginseng, separated by high-performance thin-layer chromatography (HPTLC), was optimized. Simple extraction and clean-up methods of the target constituents and the development of standardized conditions of chromatoplates with a quaternary-solvents system allowed an efficient saponins recovery from the plant material and their selective separation. After exposure of the chromatograms to thionyl chloride vapors and further heating, stable reaction products of ginsenosides, which showed absorption maxima at lambda=275 nm as well as a fluorescence (lambda(excitation)=366 nm, lambda(emission)=400 nm), allowed the application of a sensitive and reproducible method for their simultaneous determination.

In vitro antisickling activity of a rearranged limonoid isolated from Khaya senegalensis.

We previously observed that aqueous extracts of the stem bark and leaves of Khaya senegalensis exhibited a strong antisickling activity. These results prompted us to find out the constituent(s) responsible for these properties using an in vitro bio-guided fractionation. The bioassay was based on sickle cells countings, before and after deoxygenation, in blood samples taken from patients with severe sickle cell anemia and pre-incubated with the drugs to be tested.

In vitro antisickling activity of cromolyn sodium.

The improvement in sickle cell disease (SCD) children receiving cromolyn sodium therapy prompted us to investigate its antisickling activity in vitro. The number of sickle cells was determined in deoxygenated blood samples from 15 children with severe SCD. At the eight concentrations tested, cromolyn sodium exhibited a significantly higher activity than pentoxifylline, the standard compound.

Antimalarial and cytotoxic potential of four quassinoids from Hannoa chlorantha and Hannoa klaineana, and their structure-activity relationships.

Hannoa chlorantha and Hannoa klaineana (Simaroubaceae) are used in traditional medicine of Central African countries against fevers and malaria. Four stem bark extracts from H. klaineana and four quassinoids from H.

Two new taxoids from the stem bark of Taxus baccata.

Two new taxoids, 13-deoxo-13 alpha-acetyloxy-7 beta,9 alpha-diacetyl-1,2-dideoxytaxine B[1] and 7 beta-xylosyl-10-deacetyltaxol D [7], were isolated from the stem bark of Taxus baccata cv. stricta. Their structures were elucidated using spectroscopic methods and their bioactivity was evaluated using an in vitro microtubule assembly assay.

[Additional education of pharmacy students in clinical care units: a useful experience?].

Following the French program of pharmaceutical education, students of the Pharmaceutical Institute of the Université Libre de Bruxelles have taken, during six weeks, an additional training in a department of internal medicine of three university hospitals. The results of this experience show that this program modification, particularly if it is carefully prepared, is highly advantageous for the pharmacist education. Moreover, it may consolidate the collaboration between the pharmacist with the medical profession and therefore represent a contribution to Health Care.

Tissue cultures of Taxus baccata as a source of 10-deacetylbaccatin III, a precursor for the hemisynthesis of taxol.

Callus cultures of Taxus baccata L. cv. stricta were induced from hypocotyl and leaf explants on Woody Plant medium (hormone-free or additionated with phytohormones).

Immunoenzymatic methods applied to the search for bioactive taxoids from Taxus baccata.

Polyclonal antibodies raised against 2'-succinyltaxol-bovine serum albumin (BSA) conjugate were used for the immunodetection of bioactive taxoids in chromatographic fractions of the stem bark extract of Taxus baccata. In addition to taxol, cephalomannine, and baccatin III, two taxoids were isolated and their structures were elucidated as 4 alpha,7 beta-diacetoxy-2 alpha,9 alpha-dibenzoxy-5 beta,20-epoxy-10 beta, 13 alpha, 15-trihydroxy-11(15-->1)-abeo-tax-11-ene[5] and taxol C [6] using spectroscopic methods.

Immunological detection and quantitation of 10-deacetylbaccatin III in Taxus sp. plant and tissue cultures.

A high-sensitive ELISA method was developed for the detection and semi-quantitative determination of 10-deacetylbaccatin III and its structurally related compounds in crude extract of Taxus sp. plants and tissue cultures. The antibodies were raised in rabbits using 7- or 10-succinyl-10-deacetylbaccatin III-BSA conjugate as immunogen.

[Taxol and related diterpenoids of Taxus sp.: important acquisitions in the treatment of cancer].

Phytochemical and pharmacological studies on Taxus sp extracts have resulted in the isolation and the identification of several diterpenoids, and the discovery of the potent antitumor activity of taxol. This natural compound displays a unique mechanism of action as it stabilizes microtubules and inhibits their depolymerization into free tubulin. The emergence of taxol from the screening of natural products shows the benefits and the potent interest of these constituents in the search of drugs exhibiting novel mechanisms of action.