Structure of Chlorophyll f

Chlorophyll f (1) is the most red-shifted absorbing natural chlorophyll reported, and it is assigned the structure [2-formyl]-chlorophyll a (C55H70O6N4Mg). This structural assignment is confirmed based on the relative retention time on HPLC, mass spectroscopy, UV/vis absorption, and CD spectroscopy, and proton and carbon NMR of chlorophyll f purified from Halomicronema hongdechloris.