Hemi‐Indigiosin: A pH and Red‐Light Responsive Transmembrane HCl Transporter

Abstract

Abstract Synthetic anion transporters have emerged as promising therapeutic agents. However, their targeting ability is still low. Herein, we present hemi‐indigiosin, which is structurally related to prodigiosin—a well‐studied natural product exhibiting a wide range of biological activities. Our hemi‐indigiosin is shown to have similar HCl transport selectivity and pH‐dependent activity as prodigiosin, while in addition it can be deactivated by irradiation with visible light. This deactivation is effective due to high photoconversion from the active chloride‐binding Z ‐isomer to the inactive E ‐isomer, not exposing a chloride‐binding site. Transport activity is thus controlled by both pH change and light, which will allow improved targeting of pathological sites and prevent ecological impact after drug excretion into the environment.