PHOTODEGRADATION OF CHLOROPHYLL PHYTYL CHAIN IN SENESCENT LEAVES OF HIGHER-PLANTS

6,10,14-Trimethylpentadecan-2-one, 3-methylidene-7,11,15-trimethylhexa decan-1,2-diol, (Z and E) 3,7,11,15-tetramethyl-2,3-epoxyhexadecanols, (Z and E) 3,7,11,15-tetramethyl-2,3-epoxyhexadecanals and (Z and E) 3 ,7,11,15-tetramethylhexadec-2-enals were unambiguously identified in a ttached leaves of senescing Avena sativa collected during late summer. These isoprenoid compounds result from the photooxidation of the chlo rophyll phytyl chain during senescence. in vitro dark and light-induce d senescence experiments carried out with Petroselinum sativum confirm ed these results.