Natural products potential of Dictyoceratida sponges-associated micro-organisms.

The marine environment represents one of the most underexplored environments in the world. Marine sponges have a higher taxonomic diversity according to definite environmental conditions. They have been considered interesting sources for bioactive compounds. Dictyoceratida sponges are divided into five families which are widely distributed and habituating different types of micro-organisms. However, some secondary metabolites are probably not produced by the sponges themselves, but rather by their associated micro-organisms. These secondary metabolites are characterized by different chemical structures and consequently different biological activities. This review outlines the reported secondary metabolites from micro-organisms associated with Dictyoceratida sponges and their investigated biological activities from 1991 to 2019. The increasing research studies in this field can play a major role in marine microbial natural products drug discovery in the future.

Soybean-associated endophytic fungi as potential source for anti-COVID-19 metabolites supported by docking analysis.

AIMS: To identify the metabolites produced by the endophytic fungus, Aspergillus terreus and to explore the anti-viral activity of the identified metabolites against the pandemic disease COVID-19 in-silico. METHODS AND RESULTS: Herein, we reported the isolation of A. terreus, the endophytic fungus associated with soybean roots, which is then subcultured using OSMAC approach in five different culture media. Analytical analysis of media ethylacetate extracts using liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) was carried out. Furthermore, the obtained LC-MS data were statistically processed with MetaboAnalyst 4.0. Molecular docking studies were performed for the dereplicated metabolites against COVID-19 main protease (Mpro ). Metabolomic profiling revealed the presence of 18 compounds belonging to different chemical classes. Quinones, polyketides and isocoumarins were the most abundant classes. Multivariate analysis revealed that potato dextrose broth and modified potato dextrose broth are the optimal media for metabolites production. Molecular docking studies declared that the metabolites, Aspergillide B1 and 3a-Hydroxy-3, 5-dihydromonacolin L showed the highest binding energy scores towards COVID-19 main protease (Mpro ) (-9·473) and (-9·386), respectively, and they interact strongly with the catalytic dyad (His41 and Cys145) amino acid residues of Mpro . CONCLUSIONS: A combination of metabolomics and in-silico approaches have allowed a shorter route to search for anti-COVID-19 natural products in a shorter time. The dereplicated metabolites, aspergillide B1 and 3α-Hydroxy-3, 5-dihydromonacolin L were found to be potent anti-COVID-19 drug candidates in the molecular docking study. SIGNIFICANCE AND IMPACT OF THE STUDY: This study revealed that the endophytic fungus, A. terreus can be considered as a potential source of natural bioactive products. In addition to, the possibility of developing the metabolites, aspergillide B1 and 3α-Hydroxy-3, 5-dihydromonacolin L to be used as phytopharmaceuticals for the management of COVID-19.

Saccharopolyspora: an underexplored source for bioactive natural products.

Actinomycetes are a rich source for secondary metabolites with a diverse array of biological activities. Among the various genera of actinomycetes, the genus Saccharopolyspora has long been recognized as a potential source for antibiotics and other therapeutic leads that belong to diverse classes of natural products. Members of the genus Saccharopolyspora have been widely reported from several natural sources including both terrestrial and marine environments. A plethora of this genus has been chemically investigated for the production of novel natural products with interesting pharmacological effects. Therefore, Saccharopolyspora is considered one of the pharmaceutical important genera that could provide further chemical diversity with potential lead compounds. In this review, the literature from 1976 until December 2018 was covered, providing a comprehensive survey of all natural products derived from this genus and their semi-synthetic derivatives along with their biological activities, whenever applicable. Moreover, the biological diversity of Saccharopolyspora species and their habitats were also discussed.