Anthracene derivatives: Largest group of naturally occurring quinones with yellow, orange, brown or red colour (e.g. hypericin).
Almost all naturally occurring anthraquinones are hydroxylated.
Anthraquinones are found naturally in fungi (Penicillium, Aspergillus), in a few insects (e.g. in Coccionella scale insect), but mostly in higher plants (e.g. in St. John's wort).
Other examples of anthraquinone derivatives: Dantron, Chrysophagnol, Physcion, Aloe-Emodin, Rhine.