Squalamine

Squalamine /ˈskweɪləmiːn/ is an aminosterol compound with potent broad spectrum antimicrobial activity discovered in the tissues of the dogfish shark (Squalus acanthias) by a team led by Michael Zasloff. Dr. Zasloff searched the tissues of the dogfish for compounds that might help explain the hardiness of this animal to infection, despite its "primitive" immune system. Using techniques that Zasloff's team had developed to isolate and identify antimicrobial peptides from animal tissues, the team extracted and characterized a novel bile acid-like compound containing a polyamine never before seen in nature. The compound was called "squalamine", based on its source (Squalus acanthias) and its chemical structure (a sterol linked to a polyamine). Further analyses of larger quantities of dogfish liver extracts revealed squalamine to be the most abundant member of a larger aminosterol family comprising at least 12 related compounds. One of these, "MSI-1436" or trodusquemine, although structurally similar to squalamine (it carries a spermine rather than a spermidine) and also quite potent as an anti-infective, exhibits a profoundly different pharmacology in vertebrates, causing weight loss and adipose tissue mobilization. Squalamine is sometimes confused with the similar sounding squalene, an unrelated compound also found in shark liver.