Identification of bacteriophaeophytin a esterified with geranylgeraniol in an Antarctic lake sediment

Bacteriophaeophytin a with geranylgeraniol as the C-173 esterifying alcohol has been identified in a sediment from Progress Lake, east Antarctica by using atmospheric pressure chemical ionisation liquid chromatography-mass spectrometry. This transformation product of bacteriochlorophyll ageranylgeraniol, constitutes a biomarker for the presence of purple non-sulfur bacteria, most likely Rhodospirillum rubrum, in the lake at the time of sediment deposition.