Ten plugs (5 mm diameter each) of fully-grown A. violaceus mycelia on YMG agar plates were inoculated into 10 × 500 mL Erlenmeyer culture flasks, containing sterile rice media (composed of 90 mg rice in 90mL deionized water). These were incubated at 24 °C in the dark for 68 days after which the secondary metabolites were extracted. Fungal cultures were extracted by initially soaking them overnight in acetone with mild shaking at 120 rpm. The residue was then separated from acetone by filtration and the solvent evaporated. The semi-dried extract was reconstituted in distilled water and partitioned with an equal amount of ethyl acetate according to the protocol by Chepkirui et al. (2018). The aqueous phase was extracted thrice and discarded whereas the organic phase was filtered through anhydrous Na2SO4 and evaporated under reduced pressure on a rotary evaporator (Heidolph), to yield 8.0 g of dried extract. Compound 3 (10.6 mg) was further purified using a semipreparative RP-HPLC Vanquish Core HPLC system (Thermo Fisher Scientific) equipped with a VP Nucleodur 100-5 C18ec (250 × 10