Peter McCarthy of Harbor Branch Oceanographic Institution in Florida and his team scoured the seas for new antifungal drugs. They collected samples of sponges and other invertebrates from waters down to depths of 1 kilometre. After screening more than 3500 extracts, MycoLogics identified 101 interesting candidates. The most promising of these were a completely new class of anti-fungal agents called cyclic peroxy acids, which killed off both species in the test tube and act differently from many antifungals. The animal that makes the compounds is Plakinistrella, an unassuming black sponge that lives in the seas off the Seychelles.
T'he team has yet to measure the efficacy and toxicity of the compounds in people.
However, McCarthy says that spotting a new Achilles' heel in fungi is a rare and valuable insight. Several researchers have tweaked existing bases to avoid disrupting the overall structure of the DNA chain. Such modifications can upset the normal base pairing, so they are useful for introducing mutations. He created derivatives of the bases guanine and cytosine by switching the chemical groups involved in forming hydrogen bonds. These bonds form when electrons are shared between bases.