Absolute configuration of Buagafuran:An experimental and theoretical electronic circular dichroism study

Buagafuran is a novel drug candidate derived from natural product. Its absolute configuration has been confirmed by electronic circular dichroism combined with modern quantum-chemical calculation using time-dependent density functional theory. The predicted UV absorbance peak is underestimated by several nanometers compared with the experimental data. The applicability of empirical rule for the CCCO system in Buagafuran has also been discussed. Our results show that electronic circular dichroism could be a useful tool for the absolute configuration assignment of chiral drugs, especially for the oily or semisolid substances, whose crystal structures are impossible to obtain.