Chlorophyll catabolism .9. Detection, isolation and structure elucidation of a chlorophyll a catabolite from autumnal senescent leaves of Cercidiphyllum japonicum

Extracts of autumnal leaves of the dicotyledonous, deciduous tree Cercidiphyllum japonicum cultivated at the Botanical Garden of Fribourg, Switzerland, were screened for chlorophyll catabolites by TLC utilizing the chromic acid degradation test. The constitution of the isolated material was elucidated by spectroscopy. The structure, an optically active bile-pigment-like 19-formyl-1[21H,22H]bilinone derivative, reveals that this compound originates from chlorophyll a and resembles the structures of previously isolated chlorophyll catabolites from the green alga Chlorella protothecoides and from the angiosperms, the monocot Hordeum vulgare and the dicot Brassica napus.