On the sedimentary occurrence of chlorophyllone a

Abstract

The 13 2 ,17 3 -cyclopheophorbide a enol (CPP) is shown to convert mainly to a $1:1 mixture of (13 2 R=S) chlorophyllones a (Chlone), when chromatographed over silica gel or alumina supports. 15 1 -hydroxychlorophyllonelactone a and some other chlorophyll a related compounds are also tentatively identified as minor transformation products of CPP. This raises the possibility that the chlorophyllones reported in recent sediments may be analytical artifacts from CPP. However, data for the surface sediments from Lake Motte as well as literature data for other contemporary sediments show that, (i) they are not artifacts, (ii) considering that CPP is the intermediate compound in the formation of chlorophyllones from chlorophyll a, the hydroxylation of CPP in the sedimentary environment involves an enzymatic process leading preferentially to 13 2 S chlorophyllone a.

Finding of 132, 173‐cyclopheophorbide a enol as a degradation product of chlorophyll in shrunk zooxanthellae of the coral Montipora digitata

“…We also detected pheophorbide a , pheophytin a , and pyropheophytin a (which are the degradation products of chl a ) and (13 2 R / S )‐hydroxychlorophyllones a , which are the products of biotic processing (Aydin et al. , Mawson and Keely ) and/or abiotic oxidation products (Louda et al. ) of cPPB‐ a E in expelled zooxanthellae.…”

Ubiquity and quantitative significance of detoxification catabolism of chlorophyll associated with protistan herbivory

“…Given that pPhe-a is absent from our control experiments involving unialgal cultures, its accumulation can also be attributed to the heterotrophic process. However, (R/S)-hCPLs-a may be a product of biotic processing (9,10) and/or abiotic oxidation of cPPB-aE (11). All samples of heterotrophic protists also contain variable amounts of intact Chl-a, which may have been derived from undigested algal materials in phagosomes.…”

Compound-specific δ15N and chlorin preservation in surface sediments of the Peru Margin with implications for ancient bulk δ15N records

“…The high ratio of chlorophyllone to pheophytin and pyropheophytin (3.7 ± 1.5) in Peru surface sediments suggests that at a high proportion of the phototrophic biomass in sediments was consumed by protistan herbivores and that chlorophyllones were derived from 13 2 -17 3 -cyclopheophorbide a-enols. The asymmetry in abundance of the two chlorophyllone peaks is thought to be a result of enzymatic processes associated with herbivory (Aydin et al, 2003); this asymmetry is typical of chlorophyllones in modern and geologic examples Junium et al, 2011). Additionally, the similarity between the pheophytins and chlorophyllone d 15 N chlorin lends further support to a common chlorophyll source, presumably chlorophyll a, for chlorophyllone.…”