Fungal Phenylpropanoid Quantification Protocol

Fungal-derived phenylpropanoid concentrations were established in dried fungal cultures after 21 days of incubation (Supplementary Table S1), as previously described by Kulik et al. [28 (link),29 (link)] and Bilska et al. [30 (link)]. Alkaline and acid hydrolysis were conducted in sealed 17-mL culture tubes containing 0.2 g of fungal biomass. An ACQUITY H class UPLC (Ultra performance liquid chromatography) system equipped with a Waters ACQUITY Photodiode Array (PDA) detector (Waters, Milford, MA, USA) was used in the analysis. Concentrations of l-pyroglutamic acid were determined using an internal standard at a wavelength of λ = 310 nm. l-Pyroglutamic acid identification was based on a comparison of sample and standard retention times. A specific amount of the standard was added to the analyzed samples. In the next step, the analysis was repeated. The detection level was 1 μg/g. The retention time of l-pyroglutamic acid was 19.05 min.