Isolation of the chlorophyll-related pigment isochlorin-e4 from the tropical red alga Dasya pedicellata

Isochlorin-e4, a blue-green pigment related to the chlorophylls, has been isolated as a major metabolite from the tropical marine red alga Dasya pedicellata. The structure of isochlorin-e4 was assigned on the basis of comprehensive 2D 13C and 1H NMR analyses. Although isochlorin-e4 has been prepared by synthesis, this appears to be the first report of its occurrence in nature.