... during the Cenomanian–Turonian boundary OAE2 (Bonarelli Event). In this study, we have used the distributions of chlorophyll and bacteriochlorophyll degradation products, maleimides (1- H -pyrrole-2,5-diones) and high molecular weight porphyrins, to examine further the Cenomanian–Turonian boundary OAE2...

... with n -hexane:ethyl acetate (v:v 9:1) on active (120 °C for 1 h) TLC plates coated with silanized silica gel (Merck, 20 × 20 × 0.25 cm) into three subfractions. Maleimides occurred in the second subfraction (R f 0.4–0.7). For quantitative palynofacies analyses, each countable kerogen component...

... transformed by diagenesis into a large variety of chlorins (e.g., pheophytins, pheophorbides), porphyrins, maleimides, and carotanes. Their C- and N-isotopic compositions can distinguish phytoplanktonic communities and disentangle dominant nitrogen acquisition pathways (e.g., nitrate uptake versus nitrogen...

... of oxygenated plant biomarkers. One of its main components is the 3-ethyl-4-methyl-1H-pyrrol-2,5-dione. This maleimide is a very common component of sedimentary organic matter since it derives from chlorophyll a of algae and land plants (Grice et al . 1996 ). Furthermore, a cadinol, the 7...

... conditions persisted throughout the OAE in parts of northwestern Europe, while the presence of organic compounds such as isorenieratane and methyl isobutyl maleimide ( Schouten et al., 2000 ; Pancost et al., 2004 ; van Breugel et al., 2006 ) shows that euxinia sometimes extended into the marine photic zone...

... a large proportion of the world's continental shelves. Several European records of this event have yielded high concentrations of various biomarkers (aryl isoprenoids ( Schwark & Frimmel 2004 ), isorenieratane (Fig. 2 ; Schouten et al . 2000 ; van Breugel et al . 2006 ), methyl isobutyl maleimide...