Automatic differential analysis of NMR experiments in complex samples

Liquid state NMR is a powerful tool for the analysis of complex mixtures of unknown molecules. This capacity has been used in many analytical approaches: metabolomics, identification of active compounds in natural extracts, characterization of species, and such studies require the acquisition of many diverse NMR measurements on series of samples. While acquisition can easily be performed automatically, the number of NMR experiments involved in these studies increases very rapidly and this data avalanche requires to resort to automatic processing and analysis. We present here a program that allows the autonomous, unsupervised processing of a large corpus of 1D, 2D and DOSY experiments from a series of samples acquired in different conditions. The program provides all the signal processing steps, as well as peak-picking and bucketing of 1D and 2D spectra, the program and its components are fully available. In an experiment mimicking the search of an active species in natural extract, we use it for the automatic detection of small amounts of artemisin added to a series of plant extracts, and for the generation of the spectral fingerprint of this molecules. This program called Plasmodesma is a novel tool which should be useful to decipher complex mixtures, particularly in the discovery of biologically active natural products from plants extracts, but can also in drug discovery or metabolomics studies.Comment: 35 pages, 36 figures, 26 reference

Antiprotozoal Activities of Organic Extracts from French Marine Seaweeds

Marine macrophytes contain a variety of biologically active compounds, some reported to have antiprotozoal activity in vitro. As a part of a screening program to search for new natural antiprotozoals, we screened hydroalcoholic and ethyl acetate extracts of 20 species of seaweeds from three phyla (Rhodophyta, Heterokontophyta and Chlorophyta), sampled along the Normandy (France) coast. We tested them in vitro against the protozoa responsible for three major endemic parasitic diseases: Plasmodium falciparum, Leishmania donovani and Trypanosoma cruzi. The selectivity of the extracts was also evaluated by testing on a mammalian cell line (L6 cells). Ethyl acetate extracts were more active than hydroalcoholic ones. Activity against T. cruzi and L. donovani was non-existent to average, but almost half the extracts showed good activity against P. falciparum. The ethyl acetate extract of Mastocarpus stellatus showed the best antiplasmodial activity as well as the best selectivity index (IC50 = 2.8 μg/mL; SI > 30). Interestingly, a red algae species, which shares phylogenetic origins with P. falciparum, showed the best antiplasmodial activity. This study is the first to report comparative antiprotozoal activity of French marine algae. Some of the species studied here have not previously been biologically evaluated

Automatised pharmacophoric deconvolution of plant extracts – application to Cinchona bark crude extract

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Eleganolone, a diterpene from the french marine alga Bifurcaria bifurcata inhibits growth of the human pathogens Trypanosoma brucei and Plasmodium falciparum

Organic extracts of 20 species of French seaweed have been screened against Trypanosoma brucei rhodesiense trypomastigotes, the parasite responsible for sleeping sickness. These extracts have previously shown potent antiprotozoal activities in vitro against Plasmodium falciparum and Leishmania donovani. The selectivity of the extracts was also evaluated by testing cytotoxicity on a mammalian L6 cell line. The ethyl acetate extract of the brown seaweed, Bifurcaria bifurcata, showed strong trypanocidal activity with a mild selectivity index (IC(50) = 0.53 µg/mL; selectivity index (SI) = 11.6). Bio-guided fractionation led to the isolation of eleganolone, the main diterpenoid isolated from this species. Eleganolone contributes only mildly to the trypanocidal activity of the ethyl acetate extract (IC(50) = 45.0 µM, SI = 4.0). However, a selective activity against P. falciparum erythrocytic stages in vitro has been highlighted (IC(50) = 7.9 µM, SI = 21.6)

Additional file 1: of Acthaside: a new chromone derivative from Acacia ataxacantha and its biological activities

NMR and MS spectrum of the new chromone derivative (Acthaside). (PDF 439 kb

(10E,12E,14E)-9,16-Dioxooctadeca-10,12,14-trienoic acid

The title octadecatrienoic acid derivative, C18H26O4, was isolated from Silene maritima With. (Caryophyllaceae), the first time this natural compound has been found in the Caryophyllales order. This fatty acid has an 18-carbon backbone with three double bonds on trans (E) conformation and two carbonyl. In the crystal, molecules are linked via pairs of O—H...O hydrogen bonds, forming inversion dimers

Takamalalme (Psidium acutangulum Mart ex. DC): understanding the use of an antimalarial traditional remedy from French Guiana

International audienc

Antiplasmodial and anti-inflammatory effects of an antimalarial remedy from the Wayana Amerindians, French Guiana: Takamalaimë (Psidium acutangulum Mart. ex DC., Myrtaceae)

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