Development of Phosphinate Ligand-Based Low-Affinity Ca Fluorescent Probes and Application to Intracellular Ca Imaging.

Divalent metal cations such as calcium ion (Ca) and magnesium ion (Mg) are indispensable to the regulation of various cellular activities. In this research, we developed the KLCA series utilizing -aminophenol--diacetate--methylene-methylphosphinate (APDAP) as a target binding site, which was reported recently as a highly free Mg-selective ligand. with orange fluorescence based on a rhodamine fluorophore and with near-infrared (NIR) fluorescence based on a Si-rhodamine fluorophore were synthesized, intended for application to multicolor imaging.