title: Dioxasampsones A and B, two polycyclic polyprenylated acylphloroglucinols with unusual epoxy-ring-fused skeleton from Hypericum sampsonii.
abstract: Dioxasampsones A and B (1 and 2), two new polycyclic polyprenylated acylphloroglucinols with an unusual epoxy-ring-fused skeleton by new ways of cyclization, along with a new nor-PPAPs hypersampson R (3) with the loss of C-31-33 in isopentenyl, were isolated from the aerial parts of Hypericum sampsonii. 1 possessed an unexpected hexacyclic skeleton with a rare 2,7-dioxabicyclo[2.2.1]heptane moiety, and 2 featured a unique tetrahydrofuro[3,4-b]furan-fused tricycle[4.3.1.1(5,7)]undecane skeleton. The gross structures of the new compounds were determined by extensive NMR spectroscopic methods. Their absolute configurations were deduced by single-crystal X-ray diffraction and ECD calculations.
authors.affiliation: College of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University , Shenyang 110016, China.
authors.forename: Wen-Jing
authors.initials: WJ
authors.lastname: Tian
authors.forename: Yu-Qin
authors.initials: YQ
authors.lastname: Qiu
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Yao
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Chen
authors.forename: Yi
authors.initials: Y
authors.lastname: Dai
authors.forename: Xiao-Kun
authors.initials: XK
authors.lastname: Zhang
authors.forename: Xin-Sheng
authors.initials: XS
authors.lastname: Yao
mesh_terms: D004852:Epoxy Compounds / Q000737:chemistry*; D020902:Hypericum / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010696:Phloroglucinol / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000302:isolation & purification; D014961:X-Ray Diffraction
chemical_list: D004852:Epoxy Compounds; C000600370:dioxasampsone A; C000600369:dioxasampsone D; D010696:Phloroglucinol