Plakohypaphorines are halogenated indolic non-proteinogenic amino acids named for their similarity to hypaphorine (N,N,N-trimethyltryptophan). First reported in the Caribbean sponge Plakortis simplex in 2003, plakohypaphorines A-C were the first iodine-containing indoles to be discovered in nature. Plakohypaphorines D-F, also found in P. simplex, were reported in 2004 by a group including the researchers who discovered the original plakohypaphorines.