Dihydrochalcones and Diterpenoids from Pteris ensiformis and Their Bioactivities

Two new dihydrochalcone enantiomers (+)- and (-)- , along with eight known compounds - , were obtained from . The planar structures were determined on the basis of extensive 1D and 2DNMR and HRESIMS. The resolution of (+)- and (-)- was achieved by chiral HPLC analysis. The absolute configurations of (+)- and (-)- were established by the bulkiness rule using Rh₂(O₂CCF₃)₄-induced circular dichroism (ICD) method. Compounds (+)- , (-)- , , and exhibited the inhibitory assay of NO production in mouse macrophages stimulated by LPS, with IC values of 2.0, 2.5, 8.0, 9.5 and 5.6 μM, respectively. Otherwise, compound showed moderate cytotoxic activity against HCT-116, HepG-2 and BGC-823 cell lines with IC values of 3.0, 10.5 and 6.3 μM, respectively.