Figure 6. Restoring physiology to iron transporter-deficient organisms.

(A) A small molecule that autonomously performs transmembrane iron transport is hypothesized to harness local ion gradients of the labile iron pool that selectively accumulate in the setting of missing protein iron transporters. Brown spheres represent labile iron, which includes both ionic iron and iron weakly bound to small molecules such as citrate. (B) Structures of hinokitiol (Hino) and the transport-inactive derivative, C2-deoxy hinokitiol (C2deOHino). Reprinted with permission from Grillo et al ¹⁰⁷ and American Association for the Advancement of Science.