Intermediates in the oxidative pathway from torulene to torularhodin in the red yeasts Cystofilobasidium infirmominiatum and C. capitatum (Heterobasidiomycetes, Fungi)

16′-Hydroxytorulene and torularhodinaldehyde were fully characterized as end products of torulene oxidation in the red yeast Cystofilobasidium infirmominiatum. Their production increased under enhanced oxidative stress where unprecedented formation of β-apo-2′-carotenal was also observed. In cultures of C. capitatum, 16′-hydroxytorulene was the only torulene oxidation product.