Fluorescence detected exciton coupled circular dichroism: Development of new fluorescent reporter groups for structural studies

In collaboration with Jasco Corporation we have recently developed an FDCD (fluorescence detected circular dichroic) instrument J-465, which eliminates the photoselection artifacts and efficiently collects the emitted light from the sample solution based on the ideal ellipsoidal mirror principle. Using the J-465 we have investigated a variety of fluorophores with/without polarization for exciton-coupled FDCD stereochemical analysis. The following three cases extend the FDCD methodology to new challenging areas beyond the limits of conventional CD: (1) substrates containing C=C double bonds, (2) molecules with sterically hindered hydroxyls, and (3) substrates beating remote stereogenic centers. The pico- to nano-level FDCD analysis described in this paper leads to promising opportunities for the stereochemical analysis of a wide range of natural products with minuscule amounts of sample available.