Iodine in Gorgonian Corals

In 1896 Drechsel demonstrated that the horny axial skeleton of the Mediterranean coral, Gorgonia cuvolinii, contains iodine in organic combination in a nitrogenous substance termed gorgonin by him. Hundeshagen (1895) had previously investigated an iodine-containing organic material which he separated from marine sponges; and later Harnack (1898) isolated from the same source a compound which he termed iodospongin. Other investigators also have more recently studied the presence of iodine in organic combination in different organisms (McClendon, 1927). In 1901 Mendel and subsequently his pupil Cook (1905) demonstrated the occurrence of iodine in gorgonian corals from the region of the West Indies and compared their iodine content with Drechsel’s result; in 1909 Wheeler and Mendel isolated the iodine complex in sponge and identified it positively with 3,5-diiodotyrosine. Through the kindness of Professor Lafayette B. Mendel I have had an opportunity to examine specimens of several species of gorgonian corals which were collected through the assistance of Professor W. H. Longley of the Marine Laboratory of the Carnegie Institution at Tortugas, in June, 1925. Their iodine content has been determined. The method employed was essentially a combination of the procedures of Kendall and Richardson (1920) and Pickworth (1925). 0.25 to 0.50 gm. of fine powdered material (horny axial skeletons carefully separated from the crude adherent concretions of