Bioactive Natural Products from Endophytic Fungus Aspergillus nidulans Associated with Nyctanthes arbor-tristis Linn.

Abstract

Endophytic fungi are a substantial source of bioactive secondary metabolites. Present studies on Aspergillus nidulans―an endophytic fungus from Nyctanthes arbor-tristis Linn. afforded one new 1, 5-dihydroxy-3-methylxanthone-6-carboxylic acid methyl ester (1) and one known 5, 10-dihydro-phenazine-1-carboxylic acid (2) compound. The structures were elucidated by spectral techniques (Mass, 1D and 2D NMR), and their urease, carbonic anhydrase and prolyl endopeptidase inhibitory activities were evaluated. Compound 1 showed notable prolyl endopeptidase inhibition (IC50 = 3.13 ± 0.09 µM) and compound 2 showed significant carbonic anhydrase (IC50 =14.3 ± 1.05 µM) and urease (IC50 = 24.3 ± 1.15 µM) inhibition.

Urease and Carbonic Anhydrase Inhibitory Effect of Xanthones from Aspergillus nidulans, an Endophytic Fungus of Nyctanthes arbor-tristis

“…18-23 µM), respectively. However, O-acetyl sterigmatocystin (7) was less active than 3, showing 88.7 % inhibition IC 50 = 29 µM (c. i. 28-31 µM).…”

“…The fungus was isolated from the leaves of Nyctanthes arbor-tristis according to the method described earlier and identified as Aspergillus nidulans based on cultural and morphological characters [7]. The isolate has been deposited at the Karachi University Culture Collection (accession number 89).…”

“…In our ongoing search for biologically active metabolites from endophytic fungus, we investigated the ethyl acetate extract of fungal mycelium of A. nidulans from N. arbor-tristis and isolated six xanthones (1)(2)(3)(4)(5)(6). The isolated compounds and one chemically transformed metabolite (7) were evaluated for their urease inhibitory effect. Kinetics and molecular docking studies have been performed for the most active compounds.…”

“…Earlier studies showed the presence of several bioactive compounds from endophytic fungi of this plant 4 , 5 . This group reported several bioactive and structurally new metabolites from this source 6 , 7 .…”

“…and led to the isolation of five furanoxanthones, sterigmatin (1), sterigmatocystin (3), dihydrosterigmatocystin (4), oxisterigmatocystin C (5), acyl-hemiacetal sterigmatocystin (6), and a pyranoxanthone (2). Acetylation of 3 gave compound O-acetyl sterigmatocystin (7). Their chemical structures were elucidated by 1 H and 13 C NMR and MS.…”