Prenylated C6-C3 compounds from the roots of Illicium henryi

Eleven prenylated C-6-C-3 compounds, illihenryifunones A, B (1, 2), illihenryifunol A (3), illihenryipyranol A (4), illihenryiones A-G (5-11), and three known prenylated C-6-C-3 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 Mo-2(OAc)(4) in DMSO. The absolute configuration of C-11 in 4 was determined as S based on the Rh-2(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 +/- 1.30 mu M, whereas compounds 3 and 8 showed antioxidant activities with IC50 values of 44.36 +/- 0.30 and 48.00 +/- 2.01 mu M, respectively. (c) 2012 Elsevier Ltd. All rights reserved.