Trogopterins A–C: Three new neolignans from feces of Trogopterus xanthipes

Seven compounds, including three neolignans 1–3, a norlignan 4, and three diterpenoids 5–7, were isolated from the feces of Trogopterus xanthipes. Structures of these compounds were identified by 1D and 2D NMR as well as MS. The absolute configurations of compounds 1, 2, and 4 were determined by comparing CD spectra and optical rotations. Among the isolated compounds, 1–3 were novel and subsequently named trogopterins A, B, and C, respectively. Likewise, compound 4 was isolated from nature for the first time. Cytotoxic activities of compounds 1–4 were evaluated. Compounds 1–3 exhibited moderate cytotoxic activities against HL-60 cells with IC(50) values of 34.77–45.68 μM.