Search

The growing use of herbal medicines worldwide requires ensuring their quality, safety, and efficiency to consumers and patients. Quality controls of vegetal extracts are usually undertaken according to pharmacopeial monographs. Analyses may range from simple chemical experiments to more sophisticated but more accurate methods. Nowadays, metabolomic analyses allow a fast characterization of complex mixtures. In the field, besides mass spectrometry (MS), nuclear magnetic resonance spectroscopy (NMR) has gained importance in the direct identification of natural products in complex herbal extracts. For a decade, automated dereplication processes based on 13C-NMR have been emerging to efficiently identify known major compounds in mixtures. Though less sensitive than MS, 13C-NMR has the advantage of being appropriate to discriminate stereoisomers. Since NMR spectrometers nowadays provide useful datasets in a reasonable time frame, we have recently made available MixONat, a software that processes 13C as well as distortionless enhancement by polarization transfer (DEPT)-135 and -90 data, allowing carbon multiplicity (i.e., CH3, CH2, CH, and C) filtering as a critical step. MixONat requires experimental or predicted chemical shifts (δ C) databases and displays interactive results that can be refined based on the userʼs phytochemical knowledge. The present article provides step-by-step instructions to use MixONat starting from database creation with freely available and/or marketed δ C datasets. Then, for training purposes, the reader is led through a 30 – 60 min procedure consisting of the 13C-NMR based dereplication of a peppermint essential oil.

International audience; Alternaria brassicicola (Pleosporaceae) is destructive plant fungus causing black spot disease on virtually every important cultivated Brassica species including broccoli, cabbage, canola, and mustard [1,2. The pathogen is responsible for significant economic damage as infections may occasionally lead to 20 – 50% yield reductions in crops such as canola, mustard and rape. [2]. Furthermore A. brassicicola is a potent source of mold-derived allergens inducing chronic respiratory diseases such as asthma and chronic rhinosinusitis in humans. Lichens are complex symbiotic organisms consisting of fungi and cyanobacteria or algae. They are known to produce a large variety of unique secondary metabolites some exhibiting notable anti-inflammatory, antioxidant, antibacterial but also antifungal activities [3]. Despite the wide range of studied biological activities found in lichens, very little is known about their effect on A. brassicicola. The present study therefore evaluated the antifungal activity of lichen extracts and compounds on A. brassicicola using a nephelometry based method for measuring fungal growth [1]. Crude extracts of Lasallia pustulata (Umbilicariaceae), Ramalina fastigiata (Ramalinaceae), Evernia prunastri (Parmeliaceae) and Lobaria scrobiculata (Lobariaceae) were found to exhibit interesting inhibitory activities at 68.3, 42.5, 40.0 and 34.7 percent inhibition at 25 µg/Ml, respectively. Furthermore (+) usnic acid (1) (57.5% at 72.67µM) and m-scrobiculin (2) (32.5% at 59.8µM) showed notable antifungal effects.

Among the different xanthones previously isolated from the stem bark of Calophyllum caledonicum, caledonixanthone E presented the strongest activity (MIC (80) = 8 microg/mL) in acidic conditions (pH 3) against the human pathogenic fungus Aspergillus fumigatus. Phase-contrast microscopy studies suggested the assembly or synthesis of cell wall components as the target of the drug. Moreover, the use of fluorescent lectins further supported an impact of caledonixanthone E on the synthesis of chitin, the major structural polysaccharide of the fungal wall. These results suggest that caledonixanthone E may be an interesting model for the design of new antifungal drugs.

International audience; As the effects of saponins in the rumen are due to their membrane-disrupting ability on protozoa, the activities of extracts from saponin containing plants were determined on erythrocytes, Tetrahymena pyriformis and rumen protozoa. Inhibition of Tetrahymena pyriformis were found to be correlated (R2=0.54) with 50% hemolysis. The extracts supplemented to a standard feed, showed null to remarkable in vitro activity on rumen protozoa. With -51% and -41% protozoa inhibition, Primula veris and Chenopodium quinoa might have the potential to improve ammonia utilization in ruminants, meaning less excreted nitrogen and less environmental impact.

The lignoidic and alkaloidal content of the leaves, stem barks and root barks of H. GUIANENSIS has been studied; two aryltetrahydronaphthalenes, two dibenzylbutyrolactones and nine alkaloids are isolated. All components are identified by means of the spectral analysis. Eight alkaloids are aporphines and nor-aporphines.