Yellow Pigment Isolation During Optimization of Extracted Xylindein from Chlorociboria aeruginascens

The blue-green fungal pigment xylindein, extracted from species of the Chlorociboria genus, has a long history of use in the arts and is of growing interest to material scientists as a component in photovoltaic cells, textile dyes, and semiconductors. Although there is a plethora of fundamental research on xylindein, commercial scale-up of pigment production has not yet occurred, and the methodology for reliable batch culture growth is still evolving. To help aid in eventual commercial batch culturing and processing of xylindein, this research explored additional mechanical processing methods and solvent combinations. None of the physical processing steps (ultrasonication, centrifugation, and drying) produced significantly more xylindein than any other. However, all solvent combinations that contained benzyl alcohol extracted a visually significant amount of yellow color—a compound that was determined to be xylindein as well. Specifically, solvent combinations of dicholormethane (DCM) and benzyl alcohol (BA), methylethylketone (MEK) and BA, and tetrahydrofuran (THF) and MEK showed a significantly greater color shift toward the yellow spectrum. The results of this research, while unexpected, allow for control over the relative blue–yellow balance in xylindein pigment and for a reliable yellow pigment production from xylindein.