New antitumor compounds from Carya cathayensis

A new lignan (7R,8S,8′R)-4,4′,9-trihydroxy-7,9′-epoxy-8,8′-lignan, and three new phenolics, carayensin-A, carayensin-B, and carayensin-C, together with 13 known compounds were isolated from the shells of Carya cathayensis. All the compounds were evaluated for cytotocities against human colorectal cancer cell lines (HCT-116, HT-29), human lung cancer cell line (A549), and human breast cancer cell line (MCF-7).