title: Cyclized geranyl stilbenes from the rhizomes of Helminthostachys zeylanica.
abstract: Three new cyclized geranyl stilbenes, ugonstilbene A ( 1), ugonstilbene B ( 2), and ugonstilbene C ( 3), and one known compound 3-hydroxyacetophenone, were isolated from the dried rhizomes of H. zeylanica. The structures of these three new compounds were elucidated on the basis of spectral analysis. Compounds 1 - 3 exhibited moderate antioxidant activity by the DPPH assay with IC (20) of 11.31 +/- 1.11, 38.72 +/- 0.47, and 30.80 +/- 1.19 microM, respectively, while the IC (20) of Trolox was 8.70 +/- 0.95 microM.
authors.affiliation: National Research Institute of Chinese Medicine, Peitou, Taipei, Taiwan, Republic of China. ccchen@cma23.nricm.edu.tw
authors.forename: Chien-Chih
authors.initials: CC
authors.lastname: Chen
authors.forename: Yu-Ling
authors.initials: YL
authors.lastname: Huang
authors.forename: Pei-Yu
authors.initials: PY
authors.lastname: Yeh
authors.forename: Jun-Chih
authors.initials: JC
authors.lastname: Ou
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001713:Biphenyl Compounds; D029624:Ferns; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008517:Phytotherapy; D010851:Picrates; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D027343:Rhizome; D013267:Stilbenes / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D010851:Picrates; D010936:Plant Extracts; D013267:Stilbenes; C004931:1,1-diphenyl-2-picrylhydrazyl