(-)-Agelastatin C is a natural product, specifically a pyrrole-imidazole alkaloid, isolated from marine sponges. It's known for its complex tetracyclic structure and exhibits cytotoxic properties, meaning it can inhibit the growth of certain cells, including cancer cells. It was first isolated and characterized, along with (-)-Agelastatin D, from the sponge Cymbastela sp. from the Indian Ocean.