Fig 2. Representative chromatograms of CUR-2GE incubated at 37°C in buffers at pH 1.2, 4.5, pH 6.8, pH 7.4, and human plasma for 24 h, 24 h, 7 min, 7 min, and 30 min, respectively.

The retention times of curcumin, CUR-1GE and CUR-2GE were 1.6, 2.3 and 2.8 min, respectively, and the retention times of major unknown compounds 1 and 2 were 0.9 and 2.0 min, respectively.