Molecule of the Week  Exiguamine A and B  September 29, 2008
Exiguamine A (R = H) and B (R = OH), natural products derived
from a marine sponge found in the waters of Papua New Guinea,
are potent inhibitors of a promising enzyme target implicated in
several types of cancer. The total synthesis of both compounds
was reported in Nature Chemical Biology in August. They inhibit
the enzyme indoleamine-2,3-dioxygenase, which is overexpressed
in many tumor cell lines, correlates with a poor prognosis for
some cancers and seems to play a role in the “immune escape”
mechanisms that solid tumors use to avoid recognition by the
immune system.