A Novel Type of Fluorescent Chlorophyll Catabolites Hypermodified by Lipophilic Chloroplast Membrane Components

ABSTRACT Hypermodified fluorescent chlorophyll catabolites ( hm FCCs) accumulate in de‐greened leaves of banana ( Musa acuminata ). We report here the isolation of the very lipophilic hm FCC Ma ‐FCC‐114 from such leaves, a chlorophyll (Chl) catabolite with an unprecedented linolenoyl‐glyceryl‐digalactosyl hypermodification (HM). This HM with a major lipophilic part of a main chloroplast membrane constituent establishes a previously unknown link between lipid metabolism and Chl breakdown in a senescent leaf. It appears to take place by a chloroplast associated enzymatic process. The very lipophilic HM of Ma ‐FCC‐114 fosters its membrane attachment and, increases its mobility in, and across, lipid bilayers. Ma‐ FCC‐114 represents a formal direct precursor of the very abundant polar Ma ‐FCC‐61, which lacks the linolenoyl residue of Ma ‐FCC‐114, signaling its lipase‐catalyzed hydrolysis. The structures of Ma ‐FCC‐114 and Ma‐ FCC‐61 line out an effective remodeling to specific more polar hm FCCs with an enhanced tendency to dissociate from (chloroplast) membranes.