Isolation and characterization of a urobilinogenoidic chlorophyll catabolite from Hordeum vulgare L.

A new type of chlorophyll catabolite was isolated from extracts of de-greened primary leaves of barley (Hordeum vulgare cv, Lambic), Its constitution was elucidated by one-dimensional and two-dimensional (H-1,C-13)-homo- and heteronuclear NMR spectroscopic techniques and by high resolution mass spectroscopy. The isolated catabolite, a water-soluble, colorless, and nonfluorescent linear tetrapyrrole, resembles urobilinogen in which one of the propionic side chains forms a five membered isocylic ring system, indicating its origin from the chlorophylls.