Compilation of secondary metabolites produced by fungal strains identified as Aspergillus flavus var. oryzae (formerly Aspergillus oryzae), with a review of biotechnological applications, and computational studies of their anti-COVID-19 activity

Aspergillus flavus var. oryzae (formerly Aspergillus oryzae) (Aspergillaceae, Eurotiales) is one of the most significant filamentous fungi in terms of marked contributions in the pharmaceutical, industrial, food, and veterinary fields. It has been extensively utilized in fermented food production, including miso, sake, and sauce, for a very long time. Also, this fungus has drawn marked attention as a factory for producing a variety of secondary metabolites, including sesquiterpenoids, sesterterpenoids, alkaloids, anthraquinones, sterols, and phenolics, as well as furan, pyranone, and isocoumarin derivatives. Aspergillus flavus var. oryzae secretes diverse enzymes with biotechnological and industrial potential. This review focused on the reported metabolites from this fungus, including their structures, biological properties, and biosynthetic pathways from 1954 to December 2023. Additionally, the reported studies on the applications of A. flavus var. oryzae and its enzymes from 2021 to December 2023 have been surveyed. The antiviral potential against COVID-19 has been studied using computational studies, which revealed promising activities of selected compounds. This review can help direct future research into the active natural metabolites biosynthesized by A. flavus var. oryzae and inform how they might contribute to discovering new therapeutics.