Aromatic carotenoids and maleimides as indicators for photic zone euxinia

Geological carotenoid Possible biological precursors Biological sources References
okenane okenone Chromatiaceae Schaeffer et al., 19971
chlorobactane chlorobactene, hydroxychlorobactene green pigmented Chlorobiaceae Grice et al., 1998c
isorenieratane2 isorenieratene brown pigmented Chlorobiaceae Bosch et al., 1998, Grice et al., 1996b, Hartgers et al., 1993, Koopmans et al., 1996a, Pancost et al., 1998, Putschew et al., 1998, Simons and Kenig, 2001, Sinninghe Damst et al., 2001
b-isorenieratane3 b-isorenieratene, bcarotene4 brown pigmented Chlorobiaceae Grice et al., 1998c
renieratane renieratene sponges or sponge symbionts? Chlorobiaceae? Hartgers et al., 1993, Schaefle et al., 1977
renierapurpurane5 renierapurpurin sponges or sponge symbionts? Chlorobiaceae? Schaefle et al., 1977
palaerenieratane6 unknown Chlorobiaceae? Hartgers et al., 1993, Koopmans et al., 1996a, Requejo et al., 1992
2,3,6-TMAs7 chlorobactene, hydroxychlorobactene, isorenieratene, b-isorenieratene, b-carotene 4 and similar structures mostly Chlorobiaceae3 Hartgers et al., 1993, Requejo et al., 1992, Summons and Powell, 1986, Summons and Powell, 1987, Summons and Powell, 1992
2,3,4-TMAs7 okenone, renieratene renierapurpurin Chromatiaceae Chlorobiaceae? Summons and Powell, 1987
3,4,5-TMAs7 precursor of palaerenieratane Chlorobiaceae? Hartgers et al., 1993, Requejo et al., 1992, Summons and Powell, 1987
Me i-Bu maleimide BChl c, d and e Chlorobiaceae, Chloroflexaceae Grice et al., 1996a, Grice et al., 1997, Pancost et al., 2002

1 Report of okenane as a hydrogenation product of okenone after H2/PtO2 treatment of a polar fraction extracted from a Recent lake sediment

2 Also including a large variety of di- to pentacyclic early diagenetic cyclization and rearrangement products of isorenieratene (Grice et al., 1996b, Koopmans et al., 1996a).

3 Only diagnostic for Chlorobiaceae if the carbon isotopic composition of individual arylisoprenoids shows an enrichment in 13C diagnostic of the reversed tricarboxylic acid cycle

4 According to Koopmans et al. (1996b), b-carotene can undergo aromatization during diagenesis to b-isorenieratane and further degradate to 2,3,6-TMAs

5 New trivial name suggested here (= perhydrorenierapurpurin)

6 New trivial name suggested here

7 TMA = trimethylarylisoprenoids.

Chart adapted from Treatise on Geochemistry Review, Chapter 8, Summons and Brocks