Phallusia mamillata

Vanadium has long been recognized as a biologically active metal which has an important metabolic role in various marine organisms 53). A vanadium concentration 5 x 105 times that found in natural sea water has been reported in the blood of the ascidian Phallusia mamillata 57). Vanadium is concentrated in form of the blood pigment hemovanadium58). Moreover, vanadium enrichment factors of 4500 in scallops, 2500 in mussels, and 1500 in oysters were observed 59). 

Guyot, M., D. Davoust, and C. Belaud Hydroperoxy-24 Vinyl-24 Cholesterol, Nouvel Hydroperoxide Naturel Isole De Deux Tuniciers Phallusia mamillata et Ciona intestinalis. Tetrahedron Lett. 23, 1905 (1982). 

The blood of ascidians is distributed tbrougbout tbe body, tunic included, by tbe peristaltic movement of tbe heart and through a complex vascular system. The presence of high levels of vanadium in the blood cells of the Mediterranean species Phallusia mamillata, coupled with the extreme acidity of the blood (pH < 2), was reported by... 

This biosynthetic hypothesis is currently supported by the discovery of peptides and proteins containing DOPA and TOPA in blood cells of several species of ascidian. The first of these is hemovanadin, highlighted in 1948 in the cell lysate (Henze solution) of Phallusia mamillata (Colifano and Caselli, 1949). This protein is composed of two subunits, each of 27 kDa, but its structure does not appear to have been elucidated (Bielig and Bayer, 1954). Polypeptides rich in DOPA and TOPA were isolated and partly characterized in Ascidia ceratodes (Abcp-A, -B, -C, and -D) and Molgula manhattensis (Mbcp-A and Mbcp-B). ... 

Nakamura, A., Ashino, T, and Yamamoto, M. (1991) Structure determination of a very unusual peroxide from solitary ascidians, Phallusia mamillata, Ascidia ahodori, Styela plicata and Halocynthia roretzi. Tetrahedron Lett., 32, 4355-4358. 

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