Structural Elucidation and Bioactivity Studies of Secondary Metabolites from Endophytic Aspergillus niger

Humaira Naureen; Mohsen M. S. Asker; Mohamed Shaaban

Volume : V, Issue : IX, September - 2015

Structural Elucidation and Bioactivity Studies of Secondary Metabolites from Endophytic Aspergillus niger

Humaira Naureen, Mohsen M. S. Asker, Mohamed Shaaban

Abstract :

During the research for bioactive secondary metabolites from microorganisms, the endophytic fungi Aspergillus niger sp. isolate R8 was found to produce eight diverse bioactive compounds (1–8) by applying to large scale fermentation on M2–medium followed by working up and purification using a series of chromatographic techniques. Structural elucidation of the yielded compounds was achieved using intensive studies of their NMR (1H, 13C & 2D NMR) and mass (EI MS, ESI MS) spectrometry. Structures of the isolated compounds were assigned aslinoleic acid (1), R(–)–glycerol monolinoleate (2), ergosta–7,22–dien–3β,5α,6α–triol (3), aurasperone B (4), aurasperone C (5), aurasperon F (6), asperamide A (7) and cereoside C (8). In this article, taxonomical characterization, fermentation, structural characterization of the obtained metabolites were reported together with their in vitro antimicrobial assay aganist Bacillus subtilis, Staphylococcus aureus, Streptomyces viridochromogenes, Escherichia coli, Candida albicans, Mucor miehi, Chlorella vulgaris, Chlorella sorokiniana, Scenedesmus subspicatus, Rhizoctonia solani and Pythium ultimum, and cytotoxic activities against ine shrimp.