Phenolic constituents from the fresh pericarps of Juglans sigillata

Three new phenolic compounds, 2,3,4-trihydroxy-1-(4′-hydroxybenzyl)benzoic acid (1), 2,3,4-trihydroxy-1-(4′-hydroxy-3′-methoxybenzyl)benzoic acid (2), and 2-(4′-hydroxy-3′-methoxybenzyl)-3,5-dimethoxy-1,4-benzoquinone (3), were isolated from the fresh pericarps of Juglans sigillata Dode. Their structures were elucidated by integrated spectroscopic techniques. Bioactivity screening results showed that compounds 1–3 exhibited moderate neuroprotective effects against H2O2-induced or CoCl2-induced cellular damage in human neuroblastoma SH-SY5Y cell line.