Chlorophyll Catabolites in Senescent Leaves of the Plum Tree (Prunus domestica)

In cold extracts of senescent leaves of the plum tree (Prunus domestica ssp. domestica), six colorless non‐fluorescent chlorophyll catabolites (NCCs) were characterized, named Pd‐NCCs. In addition, several minor NCC fractions were tentatively classified. The structure of the most polar one of the NCCs, named Pd‐NCC‐32, featured an unprecedented twofold glycosidation pattern. Three of the NCCs are also functionalized at their 3²‐position by a glucopyranosyl group. In addition, two of these glycosidated NCCs carry a dihydroxyethyl group at their 18‐position. In the polar Pd‐NCC‐32, the latter group is further glycosidated at the terminal 18²‐position. Four other major Pd‐NCCs and one minor Pd‐NCC were identified with five NCCs from higher plants known to belong to the ‘epi’‐series. In addition, tentative structures were derived for two minor fractions, classified as yellow chlorophyll catabolites, which represented (formal) oxidation products of two of the observed Pd‐NCCs. The chlorophyll catabolites in leaves of plum feature the same basic structural pattern as those found in leaves of apple and pear trees.     

Cryptic chlorophyll breakdown in non-senescent green Arabidopsis thaliana leaves

Photosynthesis Research - Chlorophyll (Chl) breakdown is a diagnostic visual process of leaf senescence, which furnishes phyllobilins (PBs) by the PAO/phyllobilin pathway. As Chl breakdown disables...     

A novel blue fluorescent chlorophyll catabolite accumulates in senescent leaves of the peace lily and indicates a split path of chlorophyll breakdown

Colorless, non-fluorescent Chl-catabolites (NCCs) are the typical, ubiquitous products of chlorophyll (Chl)-breakdown in senescent leaves. However, a fluorescent Chl-catabolite (FCC) accumulated in de-greened leaves of Spathiphyllum wallisii (Peace Lily), which showed a weak blue luminescence. The FCC, named Sw-FCC-62, was ‘hypermodified’ with an unprecedented 6-(2-[3,4-dihydroxy-phenyl]-ethyl)-β-glucopyranosidyl ester at the propionyl group. Such esters stabilize FCCs against their typical and rapid, spontaneous isomerization to NCCs. Chl-breakdown in Sp. wallisii thus branches off from the ‘common’ path in leaves, and furnishes unique and ‘persistent’ FCCs. Our findings on ‘hypermodified’ FCCs also call for attention as to possible physiological roles of Chl-catabolites in plants.