A novel sedimentary transformation product of chlorophyll, purpurin-7 phytyl ester, has been identi®ed by atmospheric pressure chemical ionisation liquid 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 aetioporphyrins and its occu...

In a first part, visible and UV light-induced photooxidation of the main lipid cell components (chlorophylls, carotenoids, sterols, unsaturated fatty acids, highly branched isoprenoid and linear alkenes, alkenones, cuticular waxes ...) in senescent phototrophic organisms (phytoplankton, cyanobacteria, higher plants, purple sulfur bacteria and aerobic anoxygenic phototrophic bacteria) is examine...

Biosynthesis, Carotenoids, /?-Carotene, Photosynthesis Two /7-Carotene pools were obtained in the chloroplast. It is concluded that one pool is very small like a-carotene and responsible exclusively for the biosynthesis of /?-ionone-xanthophylls. The other ^-carotene pool is proposed to be the one, that is located close to photosystem I and is involved in photosynthesis as a light protecting ag...

Introduction Porphyrins are the extroverts of chemistry. Bright purple and fluorescent, they are used biologically in the processes of energy capture and utilization. Porphyrins are the key to life. It has been suggested that abiotic formation of porphyrins, in particular uroporphyrinogen would have provided the first pigments necessary for the eventual synthesis of the chlorophylls. This would...