Differential diagnosis of gallstones by using hypericin as a fluorescent optical imaging agent

Figure 10 A typical HPLC chromatogram with fluorescence detection of hypericin and its conjugated metabolites in bile from CBD-cannulated rats at 2 h after hypericin administration. Eight fluorescent peaks were observed. The peak at 1.76 min corresponded to the autofluorescence of the bile. The following six peaks with RT of 4.27, 5.03, 10.42, 12.95, 22.50 and 23.16 min appeared to represent hypericin in conjugated or metabolized forms. The last peak seemed to be unchanged hypericin eluting at 29.12 min (A). Spectrometry measurements of HPLC peaks confirmed the highest fluorescent signals from those with RT of 1.76, 10.42, 12.95 and 29.12 min (B). FLU: Fluorescence units; HPLC: High performance liquid chromatography.