N-Alkan-2-ones in peat-forming plants from the Roñanzas ombrotrophic bog (Asturias, northern Spain)

Abstract

We determined the distribution of lipids ( n-alkanes and n-alkan-2-ones) in present-day peat-forming plants in the Roñanzas Bog in northern Spain. Consistent with the observation of others, most Sphagnum (moss) species alkanes maximized at C 23, whereas the other plants maximized at higher molecular weight (C 27 to C 31). We show for the first time that plants other than seagrass and Sphagnum moss contain n-alkan-2-ones. Almost all the species analysed showed an n-alkan-2-one distribution between C 21 and C 31 with an odd/even predominance, maximizing at C 27 or C 29, except ferns, which maximized at lower molecular weight (C 21–C 23). We also observed that microbial degradation can be a major contributor to the n-alkan-2-one distribution in sediments as opposed to a direct input of ketones from plants.