One new phenanthrene, aphyllone A (1) and four new bibenzyl derivatives, aphyllone B (2) and aphyllals C-D (3-5), together with nine known compounds (6-14), were isolated from the stems of Dendrobium aphyllum (Roxb.) C. E. Fischer. The structures of these new compounds were elucidated by means of extensive spectroscopic analyses, and the absolute configuration of compound 1 was determined by single crystal X-ray diffraction and quantum calculations. Compounds 6,8 and 14 inhibited NO production at the concentration of 25 mu M in LPS-stimulated RAW264.7 cells with the inhibition (%) of 32.48, 35.68, and 38.50. Compound 2 possessed significant DPPH radical scavenging activity with scavenging percentage of 87.97% at the concentration of 100 mu g/mL. (C) 2014 Elsevier B.V. All rights reserved.
1.Yunnan Univ, Sch Chem Sci & Technol, Kunming 650091, Peoples R China 2.Chinese Acad Sci, Kunming Inst Bot, State Key Lab Phytochem & Plant Resources West Ch, Kunming 650201, Peoples R China 3.Yunnan Agr Univ, Coll Agron & Biotechnol, Kunming 650201, Peoples R China 4.Guilin Normal Coll, Guilin 541001, Peoples R China