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Beniddir M.A.,CNRS Natural Product Chemistry Institute | Grellier P.,CNRS Laboratory of Communication Molecules and Adaptation of Microorganisms | Rasoanaivo P.,Institute Malgache Of Recherches Appliquees | Loiseau P.M.,University Paris - Sud | And 4 more authors.
European Journal of Organic Chemistry | Year: 2012

Eight new diarylheptanoid glucosides 1-8 have been isolated from the leaves of Pyrostria major (A. Rich & DC.) Cavaco [syn. Canthium major (A. Rich & DC.)] Cavaco. Their structures were determined by 1D and 2D NMR spectroscopic and HRMS analyses. The absolute configurations of the diarylheptanoids 1-4 were determined to be 3S and 5S by the application of the CD exciton chirality method to the corresponding 3,5-bis(p-bromobenzoyl) (1-3) and 3,5-bis(p-dimethylaminobenzoyl) (4) derivatives. Their antiparasitic activities against Plasmodium falciparum, Leishmania donovani (amastigote forms), and Trypanosoma brucei (trypomastigote bloodstream forms) as well as their cytotoxic activities against the HL-60, KB, and MRC5 cell lines of naturally occurring diarylheptanoid glucosides and their derivatives are reported. A story of serendipity: biologically inactive natural diarylheptanoid glucosides have been isolated from Pyrostria major. Their absolute configurations were determined to be 3S and 5S by the application of the CD exciton chirality method to the corresponding benzoyl derivatives. The study led to the discovery of new compounds possessing selective antiprotozoal activity. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Girardot M.,CNRS Laboratory of Communication Molecules and Adaptation of Microorganisms | Gadea A.,CNRS Laboratory of Communication Molecules and Adaptation of Microorganisms | Deregnaucourt C.,CNRS Laboratory of Communication Molecules and Adaptation of Microorganisms | Deville A.,CNRS Laboratory of Communication Molecules and Adaptation of Microorganisms | And 5 more authors.
European Journal of Organic Chemistry | Year: 2012

Bioassay-guided fractionation of the stem bark of Muntafara sessilifolia has led to the isolation of six new vobasinyl-iboga bisindole alkaloids, tabernaelegantinals A, B and E, and (3'R)-hydroxytabernaelegantines A, C and D, together with six known monomeric indole and two bisindole alkaloids. The structures of these alkaloids were established by NMR and MS analysis. The bisindole alkaloids demonstrated cytotoxicity against the human lung MRC-5 and rat skeletal muscle L-6 cell lines whereas only one monomeric indole alkaloid was found to be cytotoxic. Tabernaemontanine acetate was found to be selectively antiplasmodial against the chloroquine-resistant strain FcB1 of Plasmodium falciparum (5.3 μM IC 50) over mammalian cell lines (selectivity index > 45). The tabernaelegantinals share an unprecedented α-amino aldehyde moiety, the biosynthetic origin of which is discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Willcox M.,Research Initiative on Traditional Antimalarial Methods RITAM | Willcox M.,University of Oxford | Benoit-Vical F.,Research Initiative on Traditional Antimalarial Methods RITAM | Benoit-Vical F.,CNRS Coordination Chemistry | And 12 more authors.
Malaria Journal | Year: 2011

Background: Over 1200 plant species are reported in ethnobotanical studies for the treatment of malaria and fevers, so it is important to prioritize plants for further development of anti-malarials. Methods. The RITAM score was designed to combine information from systematic literature searches of published ethnobotanical studies and laboratory pharmacological studies of efficacy and safety, in order to prioritize plants for further research. It was evaluated by correlating it with the results of clinical trials. Results and discussion. The laboratory efficacy score correlated with clinical parasite clearance (r s=0.7). The ethnobotanical component correlated weakly with clinical symptom clearance but not with parasite clearance. The safety component was difficult to validate as all plants entering clinical trials were generally considered safe, so there was no clinical data on toxic plants. Conclusion: The RITAM score (especially the efficacy and safety components) can be used as part of the selection process for prioritising plants for further research as anti-malarial drug candidates. The validation in this study was limited by the very small number of available clinical studies, and the heterogeneity of patients included. © 2011 Willcox et al; licensee BioMed Central Ltd.


Beniddir M.A.,CNRS Institute of Chemistry | Martin M.-T.,CNRS Institute of Chemistry | Tran Huu Dau M.-E.,CNRS Institute of Chemistry | Grellier P.,CNRS Laboratory of Communication Molecules and Adaptation of Microorganisms | And 3 more authors.
Organic Letters | Year: 2012

Two novel bisindole alkaloids, goniomedines A (1) and B (2), possessing an unprecedented quebrachamine-pleioarpamine-type skeleton, in which indole moieties are fused via a dihydropyran unit, were isolated from the stem bark of Gonioma malagasy. The structures were elucidated by comprehensive analysis of MS and NMR spectroscopic data. Their absolute configurations were deduced following the comparison of experimental and theoretically calculated ECD spectra and through biogenetic considerations. Goniomedine B (2) exhibited moderate activity against Plasmodium falciparum. © 2012 American Chemical Society.


PubMed | Latvian Institute of Organic Synthesis, Uppsala University, Institute Malgache Of Recherches Appliquees and University of Toliary
Type: Journal Article | Journal: Planta medica | Year: 2014

In a screening programme directed towards the discovery of drugs that could enhance sexual activity, we found that a decoction of the root bark of Neobeguea mahafalensis displayed an extraordinarily high potency and remarkably long duration in augmenting sexual activity in male rodents. Bioassay-guided fractionation led to the isolation of two pharmacoactive constituents, which turned out to be novel 1,8,9-orthoacetate phragmalin limonoids that we named libiguins A and B, each with a C-16/30 -lactone ring. Chemical structures were established by the interpretation of their 1D and 2DNMR data. In vivo pharmacological tests showed that starting with a treatment from 0.004-0.4 mg/kg/day for three consecutive days, over a 3-h sampling period, these limonoids induced a long-lasting augmentation of frequency and sustainment of mounting behaviour in male rodents, with an effect lasting for up to 11 days post-treatment. Libiguin A proved to be markedly more potent than libiguin B. This report is the first of limonoids having such an effect, and the findings could lead to novel therapies for the treatment of sexual dysfunction. Moreover, the results can serve as an opening to elucidate the central physiological control of mating behaviour, which is still not well mapped out.


Nicoletti M.,University of Rome La Sapienza | Maggi F.,University of Camerino | Papa F.,University of Camerino | Vittori S.,University of Camerino | And 7 more authors.
Natural Product Research | Year: 2012

The essential oil of the resurrection plant Myrothamnus moschatus (Baillon) Niedenzu endemic to Madagascar, where it is used in traditional medicine, was investigated for the first time for some biological activities. GC-FID and GC-MS analyses revealed trans-pinocarveol (35.6%), pinocarvone (20.0%), β-selinene (8.5%) and perillyl acetate (6.0%) as the major essential oil constituents. The oil strongly inhibited MDA-MB 231 (human breast adenocarcinoma) cells, with an IC50 of 15 μgmL-1, and the growth of Candida albicans, with an inhibition diameter of 18mm, while its antioxidant activity, measured by DPPH and ABTS assay, proved to be negligible. © 2012 Copyright Taylor and Francis Group, LLC.


Maggi F.,University of Camerino | Randriana R.F.,University of Antananarivo | Rasoanaivo P.,University of Antananarivo | Rasoanaivo P.,Institute Malgache Of Recherches Appliquees | And 8 more authors.
Chemistry and Biodiversity | Year: 2013

Vepris macrophylla is an evergreen tree occurring in sub-humid forest of Madagascar and traditionally used in the Island to treat several complaints as well as to prepare aromatic teas and alcoholic drinks. In the present work, the essential oil distilled from the leaves was analyzed for the first time by gas chromatography (GC-FID) and gas chromatography/mass spectrometry (GC/MS). The major compounds were citral (56.3%), i.e., mixture of neral (23.1%) and geranial (33.2%), citronellol (14.5%), and myrcene (8.3%). The essential oil exhibited antimicrobial activity against S. aureus, P. aeruginosa, and C. albicans as determined by vapor-diffusion assay, supporting the traditional use of the plant for preparing steam bath for the treatment of infectious diseases. The essential oil was evaluated for cytotoxic activity on human tumor cell lines by MTT (=3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay, showing inhibitory effects comparable to those of cisplatin, notably on MDA-MB 231 (human breast adenocarcinoma) and HCT116 (human colon carcinoma) cell lines. Finally, the essential oil was also subjected to screening for its antioxidant activity and the free radical scavenging capacity. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.


Rakotoniriana E.F.,Catholic University of Louvain | Rakotoniriana E.F.,Institute Malgache Of Recherches Appliquees | Scauflaire J.,Catholic University of Louvain | Rabemanantsoa C.,Institute Malgache Of Recherches Appliquees | And 5 more authors.
Mycological Progress | Year: 2013

A new species of Colletotrichum was described, based on morphology and phylogeny. The fungus was isolated in Madagascar from healthy leaves of Centella asiatica, in Mexico from wild native of Stylosanthes guianensis and in Colombia from Coffea arabica. The fungus differed from the currently related species in the genus by its longer and wider size of conidia. In potato dextrose agar medium supplemented with sterilized leaf powder of Ce. asiatica, the fungus produced fertile perithecia containing asci and unusual long ascospores measuring up to 90 μm. In addition to these morphological characteristics, the maximum parsimony analysis of the ITS region and β-tubulin gene placed the fungus in a distinct clade far from the currently valid Colletotrichum species. Based on the morphological and molecular characterization, Colletotrichum gigasporum sp. nov. was proposed as a new species in the genus Colletotrichum Corda. © 2012 German Mycological Society and Springer.


Girardot M.,CNRS Laboratory of Communication Molecules and Adaptation of Microorganisms | Deregnaucourt C.,CNRS Laboratory of Communication Molecules and Adaptation of Microorganisms | Deville A.,CNRS Laboratory of Communication Molecules and Adaptation of Microorganisms | Dubost L.,CNRS Laboratory of Communication Molecules and Adaptation of Microorganisms | And 4 more authors.
Phytochemistry | Year: 2012

Four vobasinyl-iboga bisindole and one 2-acyl monomeric indole alkaloids were isolated from the stem bark of Muntafara sessilifolia along with eleven known compounds. Their structures and relative stereochemistry were elucidated on the basis of spectroscopic data including 1D and 2D NMR and mass spectrometry (MS). All isolated compounds were evaluated in vitro for antiplasmodial activity against the chloroquine-resistant strain FcB1 of Plasmodium falciparum, and for cytotoxicity against the human lung cell line MRC-5 and the rat skeletal muscle cell line L-6. 3′-Oxo-tabernaelegantine A exhibited antiplasmodial activity (4.4 μM IC 50) associated with non-significant cytotoxicity (selectivity index of 48). Tabernaelegantine B and D displayed the highest cytotoxicity with IC 50 values of 0.47 and 1.89 μM on MRC-5 cells, and 0.42 and 2.7 μM on L-6 cells, respectively. © 2011 Elsevier Ltd. All rights reserved.

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