|Pangallo, Kristin C.; Reddy, Christopher M.; Poyton, Matthew; Bolotin, Jakov; and Hofstetter, Thomas B. , δ15N Enrichment Suggests Possible Source for Halogenated 1′-Methyl-1,2′-bipyrroles (MBPs), Environmental Science and Technology, doi: 10.1021/es203143c, 2012|
Polyhalogenated 1′-methyl-1,2′-bipyrroles are natural products that biomagnify into upper trophic levels of marine food webs. Here we demonstrate that they are unusually enriched in 15N (δ15N from +19.3‰ to +28.1‰) relative to other biosynthetic organic compounds measured to date and the mammals from which the compounds were isolated. We argue the 15N enrichment likely stems from enriched precursors and/or fractionation during biosynthesis and is not from MBP degradation. We also consider possible sources of MBPs in light of these results.