Figure 1. Natural occurring DARs (1–4) [2]–[6], polyene containing pigments like flexirubin (5) from Chitinophaga filiformes [8] or xanthomonadin I (6) [9], DAR (7) heterologously produced with Azoarcus DAR proteins [1] and the proposed structure of the DAR-xanthomonadin hybrid pigment named arcuflavin (8) from Azoarcus sp. BH72 identified in this study.