Insights into Phosphatase-activated Chemical Defense in a Marine Sponge Holobiont

Marine sponges often contain potent cytotoxic compounds, which in turn evokes the principle question of how marine sponges avoid self-toxicity. In a marine sponge Discodermia calyx, the highly toxic calyculin...

Synthesis of the C1–C12 Fragment of Calyculin C

Calyculins are a class of highly cytotoxic metabolites originally isolated from the marine sponge Discodermia calyx. To date, a total of twelve different calyculins (A–J) and calyculinamides (A, B and F) have been described, the most abundant (in D. calyx) being calyculins A and C. Herein, we demonstrate a concise route to access the C1–C12 tetraene fragment of calyculin C using transition-metal-catalyzed coupling reactions (Suzuki–Miyaura, Stille, Negishi and Heck) for the key connections. The synthesis starts from propionaldehyde and proceeds in 10 steps with 7.5% overall yield. We also describe an efficient route for the preparation of (Z)-3-iodobut-2-enenitrile in four steps and 68% yield.

Calyculin: Nature's way of making the sponge-derived cytotoxin

In this highlight, we focus on the recent studies addressing nature's design and biogenesis of calyculin A, a cytotoxic compound isolated from the Japanese marine sponge Discodermia calyx.