Plakohypaphorines A-C, Iodine-Containing Alkaloids From The Caribbean Sponge Plakortis simplex

Investigation of the most polar fractions obtained from the organic extract of the Caribbean marine sponge Plakortis simplex has led to the isolation of three novel iodine-containing tryptophan betaines structurally related to the known hypaphorine (5), which have been named plakohypaphorine A (2), B (3) and C (4), respectively. Their structures have been determined by application of spectroscopic methods. Isolation of compounds 2-4 is particularly remarkable since it represents the first finding of iodoindole derivatives in a natural source, either marine or terrestrial.