Neuroprotective Dihydro-β-agarofuran-Type Sesquiterpenes from the Seeds of Euonymus maackii

Twenty-one dihydro-β-agarofuran derivatives were purified from the seeds of Euonymus maackii, and eight compounds (1-8) were identified as new natural products. Their structures were deduced by extensive spectroscopic analysis, X-ray diffraction studies, and comparison of observed and reported NMR data. Compounds 10, 12, 17, and 18 significantly increased the cell viability of Aβ_25-35-treated SH-SY5Y cells with effects similar to that of epigallocatechin gallate (EGCG). In addition, the abundant compound 9 reduced the seizure-like locomotor activity of zebrafish at 10 μM compared with a pentylenetetrazol-treated group.