Synthesis, spectroscopic properties and protein labeling of water soluble 3,5-disubstituted boron dipyrromethenes

Sulfur-containing 3,5-disubstituted boron dipyrromethene (Bodipy (R)) fluorescent probes with improved water solubility were synthesized. A dicarboxylic acid derivative that can be excited by the 543 nm HeNe laser line is very soluble in aqueous solution and retains high fluorescence quantum yield of the unionizable parent molecule. Conversion of the dicarboxylic acid to the succimidyl or sulfosuccinimidyl diester produces molecules capable of labeling proteins with a bright and stable fluorescence signal. (C) 2009 Elsevier Ltd. All rights reserved.