Early diagenesis of the intact and photooxidized chlorophyll phytyl chain in a recent temperate sediment

Comparison of the stability of intact and photooxidized chlorophyll phytyl chain with depth in a core of recent sediment (where high bacterial activity was observed) allowed us to select potential markers for monitoring past photodegradation of chlorophyll. “Esterified + bound” 3-methylidene-7,11,15-trimethylhexadecan-1,2-diol appeared to be particularly suitable for such an application, but we excluded “esterified + bound” 6,10,14-trimethyl-pentadecan-2-one which is not sufficiently stable nor is it exclusively produced by photooxidation. For example, it can be produced during alkaline hydrolysis of tocopherols. Bacterial processes appeared to be particularly active on “free” isoprenoid compounds.