Solvent effect on the UV/Vis absorption and fluorescence spectroscopic properties of berberine.

Spectral and photophysical properties of the alkaloid berberine (B) were studied in solvents with different solvent parameters, using UV/Vis absorption, emission and excitation spectroscopy. The absorption and emission maxima were found to be between 421-431 nm and 514-555 nm, respectively, leading to Stokes' shifts between 4099 and 5735 cm(-1). The fluorescence quantum yields varied between 10(-2)-10(-4), depending on the solvent.