A Strategy for the Rapid Identification of Fungal Metabolites and the Discovery of the Antiviral Activity of Pyrenocine a and Harzianopyridone

Abstract

The isolation and identification of bioactive metabolites from complex extracts obtained from microbial growth media is a time consuming, costly, and labor-intensive task. A strategy to rapidly identify secondary metabolites isolated from extracts obtained from the culture media of marine-derived and endophytic fungal strains is described. Identification was achieved by HPLC-UV-MS and 1 H NMR analyses in combination with data obtained from the Dictionary of Natural Products. Among the compounds identified, (-)-naphthoquinoneimine, citreorosein, emodin, pyrenocine A and harzianopyridone displayed moderate to potent antiviral activity. (-)-Naphthoquinoneimine was isolated as the enantiomer of its previously reported dextrorotatory congener, while 6,7-dihydroxy-2,2-dimethyl-4-chromanone is herein reported for the first time as a natural product.

Fungal quinones: diversity, producers, and applications of quinones from Aspergillus, Penicillium, Talaromyces, Fusarium, and Arthrinium

“…Several quinones have anti-viral effects. Ióca et al (2016) found that naphthoquinoneimine (13) isolated from an Aspergillus strain and emodin (98) and ω-hydroxyemodin (=citreorosein) (104) isolated from Penicillium strains had moderate to strong activity against several vira (Avian metapneumovirus (AMPV), Bovine diarrhea virus (BVDV), Herpes Simplex Virus Type 1 (HSV-1)). Additionally, Huang et al (2017) found anti-viral effect against HSV-1 with the AQs aspergilol H (137) and I (138) isolated from A. versicolor.…”

Mass Spectrometry: A Rosetta Stone to Learn How Fungi Interact and Talk

“…One of the most common methods used to achieve the best separation of secreted specialized metabolites produced by fungi is reverse phase (C-18) chromatography since it is more than ideal to interact with polar and some non-polar metabolites [150,[180][181][182]. In some cases, before injecting samples on LC, samples are needed to be purified on small solid phase extraction (SPE) columns to remove chromatography-impairing lipids and phospholipids [147,148,183].…”

Anticancer Potential of Compounds from the Brazilian Blue Amazon

“…One strain, Pseudovibrio denitrificans Ab134, was further shown to produce bromotyrosine-derived alkaloids, which have been previously isolated exclusively from marine sponges [59]. Nevertheless, compounds obtained from fungal and bacterial communities associated with marine sponges have been evaluated majorly for anti-inflammatory, antibiotic, antiviral, and cytotoxic activities; however, the observed cytotoxicity on cancer cells was not very stimulating, and most of isolated compounds were further studied for antiviral properties [60][61][62][63]. Indeed, a role of microbial sponge symbionts in the production of cytotoxic compounds that can be potentially applied in anticancer therapies remains to be better studied and evaluated.…”