Les champignons endophytes sont des organismes qui vivent à l’intérieur de communautés de champignons endophytes de racines de deux espèces de. L’inoculation du pois chiche avec des champignons endophytes indigènes en serre a manipulation de leurs champignons endophytes par inoculation. champignons endophytes du “Rhynia gwynne-vaughanii” K. et L. etude morphologique et deductions sur leur biologie . Boullard, B. Lemoigne, Y.
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Le champignon endophytique Chaetomium sp.
Mycoflore des aiguilles de Pinus banksiana et Pinus resinosa. I. Champignons endophytes
This study reports the chemical investigation and cytotoxic activity of the champigbons metabolites produced by the endophytic fungus Chaetomium sp. The endophytic fungus Chaetomium sp. The fungal strain was identified by PCR.
The crude organic extract of the fungal strain was proven to be active when tested for cytotoxicity against LY mouse lymphoma cells. Chemical investigation of the secondary metabolites showed that cochliodinol is the main component beside isocochliodinol.
They reside inside the tissues of nearly all healthy plants. The relationship that they establish with the plant varies from symbiotic to bordering on pathogenic Strobel, a. Via what appears to be their contribution to the host plant, the endophytes may produce a plethora of substances of potential use to modern medicine, agriculture, and pharmaceutical industry. Historically, it is well known for its endophytex, virustatic and tannin-based anti-microbial properties. The following gradient was used MeOH, 0.
Stems were rinsed in sterilized distilled water twice.
The material was placed on a Petri dish malt agar medium containing an antibiotic to suppress bacterial growth medium composition: A small part of the medium from a Petri dish containing the purified fungus was transferred under sterile conditions to the rice medium. Exponentially growing cells were harvested, counted and diluted appropriately. The small amount of ethanol present in enndophytes wells did not affect the experiments. The yellow MTT penetrates into the living cells and in the presence of mitochondrial dehydrogenases, MTT is transformed to a blue formazan complex.
The colour intensity is correlated with the number of healthy living cells. As controls, media with 0. In the 1 H NMR spectrum, all resonances originate from pairs of chemically equivalent groups due to symmetry in the molecule. Furthermore, chqmpignons proton and carbon resonances had chemical shifts and multiplicities consistent with the presence of a disubstituted indole residue.
The position of the attachment of the isoprenyl side chain to the aromatic side of the indole substructure was evident by the long range correlations of CH 2 -8 to both H-4 and H-6 in the COSY spectrum. Accordingly, correlations of H-2 to both C-3a and C-7a indicated that a further substituent had to reside at C-3 in the heteroaromatic ring of the indole moiety.
Most diagnostic for unambiguously deducing the position of the isoprenyl side chain proved a correlation of H-4 to C-3 in the HMBC spectrum, the corresponding proton signal was the one exhibiting the meta-coupling, thus representing the proton immediately adjacent to the substituent.
Thus, 2 had to represent a symmetrical isomer of cochliodinol 1leaving a positional isomer with the prenyl group attached to C-6 as the most probable alternative. As in the case of cochliodinol, the COSY spectrum confirmed that the isoprenyl group was attached to the aromatic side of the indole substructure since CH 2 -8 exhibited long range correlations of to both H-7 and H However, in the case of compound 2this proton signal was the one exhibiting the ortho-coupling, proving that the side chain was situated meta with regard to H-4 and thus resided at C Based on these observations, compound 2 was identified as the known isocochliodinol which was confirmed by comparison of its UV, 1 H NMR and mass spectral data with published data Sekita, The compound was previously obtained from several Chaetomium sp.
First, the percentage of cell survival was determined and results were compared to those of untreated controls.
Cochliodinol proved to be highly active against the cancer cell line with an EC50 of 7. Thus, it may be concluded that cytotoxic activity was affected by the position of prenyl substituents at the indole rings.
Accordingly, because of their role in conferring plants the ability to adapt to stress conditions, and because they are proven or perceived sources of secondary metabolites with pharmaceutical importance, the study of fungal endophytes is expected to become an important component of fungal biology Maheshwari, Taking into consideration that despite competition from other drug discovery methods, natural products are still providing their fair share of new clinical candidates and drugs Butler, we intend to continue our specific search for bioactive substances with pharmaceutical potential as well as contribute to the question of the ecological function of secondary metabolites produced by endophytic fungi aiming to a better understanding of this interesting group of organisms.
Topical anti-inflammatory activity of Salvia officinalis L. Ethnopharmacology75 The antibacterial activity of some naturally occurring 2,5-dihydroxy-1,4-benzoquinones.
Canadian Forest Service Publications
The role of natural product chemistry in drug discovery. Evaluation of a tetrazolium-based semiautomated colorimetric assay: The chemistry of cochliodinol, a metabolite of Chaetomium spp.
What is an endophytic fungus? Mycotoxin production by Chaetomium spp. Isocochliodinol and neocochliodinol, bis 3-indolyl – benzoquinones from Chaetomium spp. Rainforest endophytes and bioactive products.
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Microbial gifts from rain forests. Bioprospecting for microbial endophytes and their natural products. Secondary metabolites from endophytic Streptomyces aureofaciens CMUAc and their antifungal activity. Received on February 4,accepted on July 2, Plant material and endopuytes isolation.
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Taxonomic identification of the fungus. Rice culture of isolated fungus. Material and methods 2. Plant material and fungal isolation 4 Fresh healthy stems of S. Taxonomic identification of the fungus 6 A section 0. Results and discussion 18 The crude ethyl acetate extract of rice cultures of Chaetomium sp.