Phenolic cyclobutantetraol esters from Scindapsus officinalis (Roxb.) Schott.

Five new caffeoyl cyclobutantetraol esters (1-5) and one hydroxycinnamoyl cyclobutantetraol ester (6), were isolated from Scindapsus officinalis (Roxb.) Schott, which were the first reported phenolic metabolites incorporating a cyclobutantetraol in nature. Structures of the isolated compounds, including absolute configurations, were elucidated by spectroscopic analysis, especially 2D NMR techniques and exciton chirality CD (ECCD) method. All isolates were evaluated for cytotoxic activity toward MCF-7 human breast cancer cell, anti-inflammatory activity against nitric oxide (NO) production, and their antioxidative activity in the 1,1-diphenyl-2-picrylhydrazyl assay in vitro. Compound 1 showed strong antioxidative activity with IC50 value of 59.2 μM, and compounds 1-6 exhibited weak inhibitory effects on NO production, while hardly showing any cytotoxic effects against MCF-7 cell.