Biosynthetic origin of the saw-toothed profile in δ13C and δ2Η of n-alkanes and systematic isotopic differences between n-, iso- and anteiso-alkanes in leaf waxes of land plants

Low abundance even-carbon-numbered n-alkanes have been identified in higher plant leaf waxes, however, in contrast to odd-carbon-numbered n-alkanes in numerous studies, uncertainties exist as to their biosynthetic precursor. We provide stable carbon and hydrogen isotopic evidence to suggest pyruvate as a precursor and a tentative pathway is presented. We also provide a biochemical explanation for the observed isotopic order of δ2Hn-alkane > δ2Hiso-alkane > δ2Hanteiso-alkane.