Snail hypobranchial glands

V. Erspamer, Active constituents of the posterior salivary glands of octopods and of the hypobranchial gland of the purple snail. Arzneimittelforschung 2 253-258 (1952)... 

The color was, and still is, prepared from several mollusks including Murex brandaris, Murex trunculus and Purpura haemostoma, found on the shores of the Mediterranean and the Atlantic coast as far as the British Isles [31, 32]. The method of extraction and preparation of the colorant was one of the most complex, time-consuming, and labor-intensive activities carried out by the ancients. The reasons are (1) it purportedly takes 10,0(X) shellfish to produce one gram of the pure colorant (see Fig. 4.7) (2) the colorant itself is not actually present in the living animal but its precursor must be excised from the snail s hypobranchial gland (3) the colorant must be produced by a complex chemical process involving enzymatic hydrolysis of the dye precursors and subsequent photochemical oxidation. 

In the order Muricidae these carnivorous snails attack molluscs or sessile crustaceans by boring holes in their shells using softening secretions. Hypobranchial and other glands contain small molecular weight substances with pharmacological activity (e.g., murexine, 5HT, etc.). 

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