3.1.9. Azaphilones from *Talaromyces* Genus

Most strains previously referred to as *Penicillium* sp. are now classified in the *Talaromyces* species, and some of them have been found to produce yellow and red azaphilone pigments. Two new pigments from *T. atroroseus* were described. The first belongs to the series of known *Monascus* orange azaphilone PP-O pigments, and it was unequivocally elucidated as the isomer *trans*-PP-O (**91**) [32] (Figure 9). The second was

the unique azaphilone atrosin S, which presented the incorporation of a serine moiety into the isochromene/isoquinoline system. The fungus cultivation in medium enriched with a specific amino acid as sole source of nitrogen could allow seven atrorosin derivatives (atrorosin D, E, H, L, M, Q, and T, depending on the amino acid incorporated) (**92–99**), which were identified by dereplication using HPLC-DAD-MS/HRMS analysis [32]. From the fungus *Talaromyces albobiverticillius* associated with the isopod *Armadillidium vulgare,* two interesting azaphilone pigments talaralbols A and B (**100–101**) was reported [58]. However, talaralbol B presents the same planar structure of trans-PP-O, early described in *T. atroroseus* [32], in which the C-9 stereochemistry was not reported.

**Figure 9.** Chemical structures of *Talaromyces* azaphilones: **91**: trans-PP-O; **92–99**: atrosins S (Ser),D (Asp), E (Glu), H (His), L (Leu), M (Met), Q (Gln), and T (Trp); **100–101**: talaralbols A and B [32,58].
