Optically functional isoxanthopterin crystals in the mirrored eyes of decapod crustaceans

• DOI: 10.1073/pnas.1722531115
• Publication Date: 2018-02-20T19:32:27Z
• Authors: Benjamin A. Palmer; Anna Hirsch; Vlad Brumfeld; Eliahu D. Aflalo; Iddo Pinkas; Amir Sagi; Shaked Rosenne; Dan Oron; Leslie Leiserowitz; Leeor Kronik; Steve Weiner; Lia Addadi
• Keywords: Pteridine; Crystal (programming language)

Significance Some aquatic animals use reflectors in their eyes either to form images or increase photon capture. Guanine is the most widespread molecular component of these reflectors. Here, we show that crystals isoxanthopterin, a pteridine analog guanine, both image-forming “distal” mirror and intensity-enhancing tapetum reflector compound some decapod crustaceans. The crystal structure isoxanthopterin was determined, providing an explanation for why are so well suited efficient reflection. Pteridines were previously known only as pigments, our discovery raises question which other organic molecules may be used with superior reflective properties organisms artificial optical devices.