Anti-Respiratory Syncytial Virus Compounds from Two Endophytic Fungi Isolated from Nigerian Medicinal Plants

Abstract

Respiratory syncytial virus (RSV) is known to cause severe respiratory infections particularly in infants younger than 2 years of age. The only approved drug, ribavirin, is expensive and is not likely to improve therapeutic outcome, thereby necessitating the search for safer and more potent alternatives from natural sources such as endophytic fungi. The present study aimed to investigate the anti-RSV activity of compounds from endophytic fungi. Two endophytic fungi and were isolated from the fresh leaves of the host Nigerian plants and respectively. After fermentation in solid rice media, afforded 4 known compounds 4-hydroxybenzoic acid (), vanillic acid (), ferulic acid () and N-acetyltryptamine ( while afforded 3 known compounds chloroisosulochrin (), ficipyrone A () and pestheic acid (). The compounds were investigated for their anti-RSV activity using the HEP-2 cell lines and ribavirin as the standard drug. Compound was found to show the strongest inhibition of the RSV with IC of 4.22±1.03 µM (ribavirin 4.91±1.85 µM). Other compounds showed moderate inhibition of the virus (IC ranging from 45.00±0.98 to 259.23±2.36 µM). The results of the present study have shown that chloroisosulochrin (), isolated from an endophytic fungus possesses strong activity against RSV.

Biological Evaluation and In Silico Study of Benzoic Acid Derivatives from Bjerkandera adusta Targeting Proteostasis Network Modules

“…Thus, it was hypothesized that the bioactivity of the EtOAc-LL was attributed to the presence of those compounds. A purification process using semi-preparative HPLC was followed and the structures of compounds 1-4 (Figure 3) were elucidated by the extensive use of 1D and 2D-NMR spectroscopy, supported by HRMS spectra and by comparison with literature data (Figures S2-S11) [23][24][25][26]. S11) confirmed the presence of one and two chlorine atoms, respectively.…”

Naturally Occurring Asterric Acid Analogs: Chemistry and Biology

“…Recently, pestheic acid (16) was also isolated from P. theae collected from the fresh leaves of Fagara zanthoxyloides. 25 As part of an investigation of coprophilous and folicolous fungi as sources of bioactive compounds, Ghisalberti's group isolated two asterric acid analogs methyl dichloroasterrate (17) and methyl chloroasterrate (18) from an Aspergillus sp. 26 Together with methyl asterrate (3), methyl 3-chloroasterric acid (19) and methyl 3,5-dichloroasterric acid (20) were isolated from an unidentified fungal strain B90911.…”

“…To date, there are more than 50 asterric acid analogs isolated from diverse bioresources mainly from fungi, including Aspergillus, Oospora, Penicillium, Chrysosporium, Pestalotiopsis, Scytalidium, Leptosphaerulina, Xylaria, Neoplaconema, Geomyces, Corynespora, Steganospora, Phoma, Verticillium, Alternaria, Pleosporales, Pseudogymnoascus, Saccharomonospora (Table ). − In addition, several reports claimed that some analogs were ever isolated from different plants, − ,, which suggested an interesting question whether asterric acid analogs isolated from plants might be biosynthesized through the plant endophytic fungi or pathogens.…”

Shielding Effects of Aromatic (Indole) Ring for Structural Analysis

“…According to the empirical rule about the shielding effect of the B-ring on H-6 (A-ring), the chemical shift values of H-4/C-4, H-6/C-6, and C-1/C-3 in some asterric acid analogs mistakenly characterized were revised (as shown in Figure ). − …”