Figure 3. High-performance liquid chromatography (HPLC) elution profile of the degradation products of the pigment that we extracted from the valves of the chiton Acanthopleura granulata (where absorption was set at 280 nm). The solid line represents the digestion product of the extracted pigment. For reference, the dashed line represents the same digestion reaction minus the pigment. The inset shows an elution profile for the degradation products of synthetic pheomelanin (DOPA-cysteine melanin) from Panzella et al. (2007), a paper whose methods we replicated. We hypothesize that the distinct peak that we see at 30 min in our elution profile represents BTCA, a diagnostic degradation product of pheomelanin.