A novel sedimentary chlorin: structural evidence for a chlorophyll origin for aetioporphyrins

A novel sedimentary transformation product of chlorophyll, purpurin-7 phyty l ester, has been identified by atmospheric pressure chemical ionisation li quid chromatography mass-spectrometry in sediments from Lake Baikal, Russia , Loch Ness and Priest Pot, UK. This product of oxidative transformation is an intermediate on the transformation pathway leading to sedimentary aetio porphyrins and its occurrence lends strong support to the view that aetiopo rphyrins derive mainly from precursor chlorophylls. (C) 2000 Elsevier Scien ce Ltd. All rights reserved.