Structure of a novel flavin chromophore from <em>Avena</em> coleoptiles, the possible 'blue light' photoreceptor.

A yellow chromophore has been isolated from Avena coleoptiles grown in the dark. It had previously been shown by Zenk[zenk, M.H.(1967)Z.Pflanzenphysiol.56 ,122 -122-140] to be a flavin of still unidentified structure, and had been suggested to be "blue light' photoreceptor in this organism. The structure of this flavin (F1-X) has been obtained synthetically. The 5' malonylester linkage is relatively labile towards hydrolysis and photolysis, it flavin (absorption and florescence) are practically identical to those of normal riboflavin (vitamin B₂. [ABSTRACT FROM AUTHOR]