Spiroindolone

The spiroindolones are a class of compounds in which an indolone ring is substituted with another ring in a spiro arrangement.

Chemical structure of cipargamin, a spiroindolone being studied as an antimalarial agent

Alkaloids in this class include horsfiline, rhynchophylline, gelsemine, carapanaubine, and maremycin E.

Spiroindolones are also an emerging class of antimalarial drugs^[1] whose mode of action is to inhibit protein synthesis in the target parasite. The most advanced compound in this class in terms of drug development is cipargamin (NITD609).^[2]