Prenylated C6–C3 compounds from the roots of Illicium henryi

Prenylated C6–C3 compounds, illihenryifunones A, B, illihenryifunol A, illihenryipyranol A, illihenryiones A–G, together with three known prenylated C6–C3 compounds, were isolated from the roots of Illicium henryi. The antioxidant activities of compounds 1–14 were examined. [Display omitted] ► Fourteen prenylated C6–C3 compounds were isolated from the roots of Illicium henryi. ► Eleven prenylated C6–C3 compounds were hitherto unknown. ► Five compounds were glucosides of prenylated C6–C3 compounds analogs. ► Three compounds exhibited antioxidant activities. Eleven prenylated C6–C3 compounds, illihenryifunones A, B (1, 2), illihenryifunol A (3), illihenryipyranol A (4), illihenryiones A−G (5–11), and three known prenylated C6–C3 compounds (12–14), were isolated from the roots of Illicium henryi. Structures of 1–11 were elucidated by spectroscopic methods including NMR, HRESIMS, and CD. The absolute configuration of the 11,12-diol moiety in 5 was determined by observing its induced circular dichroism after addition of Mo2(OAc)4 in DMSO. The absolute configuration of C-11 in 4 was determined as S based on the Rh2(OCOCF3)4-induced CD data; the absolute configuration of 3 was determined as R by comparison of its experimental and calculated electronic circular dichroism (ECD). The antioxidant activities of compounds 1–14 were also evaluated. Compound 4 exhibited strong antioxidant activity with an IC50 value of 2.97±1.30μM, whereas compounds 3 and 8 showed antioxidant activities with IC50 values of 44.36±0.30 and 48.00±2.01μM, respectively.