Fungal quinones can be used for a variety of applications, such as pharmaceuticals, food colorants, textile dyes, and battery electrolytes. However, when producing quinones by fungal cultivation, many considerations arise regarding the feasibility of a production system, such as the quinone yield, purity, ease of extraction, and the co-production of mycotoxins. In this work, we display the initial screening of filamentous fungi for quinone production and evaluate their potential for future optimization. We investigated toluquinone (TQ) potentially produced by Penicillium cf. griseofulvum, terreic acid (TA) produced by Aspergillus parvulus and A. christenseniae, and anthraquinone (AQ) monomers and dimers produced by Talaromyces islandicus. The strains grew on various agar and/or liquid media and were analyzed by ultra-high-performance liquid chromatography-diode array detection-quadrupole time-of-flight mass spectrometry (UHPLC-DAD-QTOF MS). In the case of AQs, feature-based molecular networking (FBMN) was used for the identification of AQ analogs. TQ was not observed in the production strains. TA constituted one of the major chromatogram peaks and was secreted into the growth medium by A. parvulus. The AQs constituted many major chromatogram peaks in the mycelium extracts and endocrocin and citreorosein were observed extracellularly in small amounts.
Keywords: Aspergillus; HPLC; Penicillium; Talaromyces; anthraquinone; anthraquinone dimer; mass spectrometry; quinone; terreic acid; toluquinone.