| Since its discovery nearly a century ago, alpha-tocopherol (vitamin E) research has been mainly focused on its ability to terminate the cycle of lipid peroxidation in membranes. Nitrobenzoxadiazole fluorescent analogues were made previously to study the intracellular transfer of vitamin E in cells. However, these molecules were reportedly susceptible to photobleaching while under illumination for transfer assays and microscopy.;Here is reponed the synthesis of a series of fluorescent analogues of vitamin E incorporating the more robust dipyrrometheneborcn difluoride fluorophore (BDP-alpha-Tocs; gammaex = 507 nm, gammaem = 511 nm). C8-BDP-alpha-Toc 42c, having an eight-carbon chain between the chromanol and fluorophore, was shown to bind specifically to alpha-tocopherol transfer protein with a dissociation constant of approximately 100 nM. Another fluorescent analogue of vitamin E with a thienyl derivative of BODIPY that is excited and fluoresces at longer wavelengths (gammaem =561 nm gammaem = 570 nm) is in development. |
