Withanolide production by fungal endophyte isolated from Withania somnifera.

Withanolides, the secondary metabolite from Withania species is used in Ayurvedic medicine and now proved to have potential use in treating cardiovascular, Alzheimer's disease, etc. Its production in plants varies between genotypes with very low yield. For improved industrial commercialisation, there is a need to increase its production. Endophytic fungi are symbiotically associated with plants and can synthesise the same bioactive compounds and natural products as their host plant. There are no reports available on withanolide-producing (endophytic) fungi. The present study identified an endophytic fungus (Taleromyces pinophilus) from leaves of Withania somnifera which produces withanolides in the medium. The structure of withanolide was confirmed by 1H NMR, LC-MS analyses and quantified by HPLC analysis. The fungus produces high amount of withanolide when compared to leaf and root of W. somnifera. The fungus can be exploited to produce the withanolide to meet its demand.

Lovastatin-producing endophytic fungus isolated from a medicinal plant Solanum xanthocarpum.

Lovastatin is a potent drug for lowering blood cholesterol. An endophytic fungus Phomopsis vexans was isolated from the healthy leaf tissues of Solanum xanthocarpum, a medicinal plant, and screened for lovastatin production. The fungus was identified by their characteristic cultural morphology and molecular analysis. The strain had a component with the same TLC Rf value and HPLC retention time as authentic lovastatin. The presence of lovastatin was further confirmed by FT-IR, UV, (1)H, (13)C NMR and LC-MS analyses. The amount of lovastatin produced by this endophytic fungus was quantified to be 550 mg/L, and thus the fungus can serve as a potential material to improve the production of lovastatin.

ß-D-Glucan nanoparticle pre-treatment induce resistance against Pythium aphanidermatum infection in turmeric.

In vitro experiments were carried out to test the efficacy of GNP (ß-D-glucan nanoparticle prepared from mycelium of Pythium aphanidermatum) against rhizome rot disease of turmeric (Curcuma longa L.) caused by P. aphanidermatum. GNP (0.1%, w/v) was applied to rhizome prior to inoculation with P. aphanidermatum (0 h, 24 h). Cell death, activities of defense enzymes such as peroxidase, polyphenol oxidase, protease inhibitor and ß-1,3 glucanase were monitored. Prior application of GNP (24 h) to turmeric rhizome effectively controls P. aphanidermatum infection. The increase in defense enzyme activities occurred more rapidly and was enhanced in P. aphanidermatum infected rhizomes that were pre-treated with GNP. Pre-treatment also induced new isoforms of defense enzymes. Increased activities of defense enzymes suggest that they play a key role in restricting the development of disease symptoms in the rhizomes as evidenced by a reduction in cell death. The results demonstrated that GNP can be used as a potential agent for control of rhizome rot disease.

Gymnemagenin-producing endophytic fungus isolated from a medicinal plant Gymnema sylvestre R.Br.

Gymnema sylvestre is a plant containing the triterpenoid gymnemagenin, which is used in the pharmaceutical industry as an antidiabetic agent. The objective of this study was to determine whether endophytic fungi, isolated from G. sylvestre, produce gymnemagenin. We isolated an endophytic fungal strain from the leaves of G. sylvestre which produces gymnemagenin in the medium. The fungus was identified as Penicillium oxalicum based on morphological and molecular methods. The strain had a component with the same TLC Rf value and HPLC retention time as authentic gymnemagenin. The presence of gymnemagenin was further confirmed by FTIR, UV, and (1)H NMR analyses.