Bioactive neolignans and lignans from the roots of Paeonia lactiflora

Two new neolignans and one new lignan (1-3) were obtained from the roots of Paeonia lactiflora. Their structures were unambiguously elucidated based on extensive spectroscopic analysis, single-crystal X-ray crystallography, and the calculated and experimental electronic circular dichroism (ECD) spectra. Compound 1 was a racemic mixture and successfully resolved into the anticipated enantiomers via chiral-phase HPLC. Compound 3 demonstrated moderate inhibitory activity against human carboxylesterase 2A1 (hCES2A1) with an IC50 value of 7.28 +/- 0.94 mu mal.L-1 .

Automated summary

Two new neolignans and one new lignan were isolated from the roots of Paeonia lactiflora. Their structures were determined using various spectroscopic techniques, X-ray crystallography, and electronic circular dichroism. One of the compounds exhibited moderate inhibitory activity against human carboxylesterase 2A1.