Two pairs of chlorine-containing phenylpropanoid enantiomers from Acorus tatarinowii

Two pairs of chlorine-containing phenylpropanoid enantiomers ( 1a/1b and 2a/2b ) were isolated from the rhizomes of Acorus tatarinowii . Interestingly, these optical isomers ( 1a/1b and 2a/2b ) were co-existed in the same plant, which were characterized as the first halogen-containing natural products from the genus Acorus . Their structures and absolute configurations were elucidated by a combination of spectroscopic analysis and a single-crystal X-ray diffraction, assisted by a modified Mosher’s method. The phenylpropanoid isomers ( 1a/1b and 2a/2b ) were evaluated for their antioxidant activities using DPPH assay and cytotoxic activities against five human cancer cell lines.