Melanins: Skin Pigments and Much More—Types, Structural Models, Biological Functions, and Formation Routes
Figure 4
Trichochrome F: this is a typical trichochrome, but there are other variants from color orange to violet depending on the groups at position 2 and the possible double bond at position 3 of the thiazine ring. These molecules are dimers of two benzothiazine units, and they can be considered small pheomelanins with a well-defined structure.