A widespread and abundant chlorophyll transformation product in aquatic environments

An abundant chlorophyll a transformation product, found previously in a lake sediment (chlorophyllone a) has been identified by LC-MS in sediments from five aquatic environents, both marine and lacustrine. Its previously unrecognized wide sedimentary occurrence and apparent post burial stability suggest it is an important preservational sink for the chlorophyll produced in the euphotic zone. It contains a seven-membered ring fused to a five-membered ring, and therefore provides further evidence for a transformation pathway linking chlorophyll a to a recently reported sedimentary bicycloalkanochlorin and a suite of sedimentary porphyrins of the bicycloalkanoporphyrin (bi-CAP) type.