title: Two new isomeric alpha-tetralones from Pyrola calliantha.
abstract: Callianthones A ( 1) and B ( 2), a pair of new isomeric alpha-tetralones, together with a known alpha-tetralone ( 3) and four known flavonoids ( 4 - 7) were isolated from the 50 % EtOH extract of Pyrola calliantha. The structures and absolute configurations of the two new isomers were established to be (2 S,4 R) - and (2 S,4 S)-2,4-dihydroxy-2,7-dimethyl-3,4-dihydronaphthalen-1(2 H)-one ( 1 and 2, respectively) on the basis of spectral analysis, including 2 D NMR, model studies, and CD spectra.
authors.affiliation: State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Science, Chinese Academy of Sciences, Shanghai, P. R. China.
authors.forename: Yi-Lei
authors.initials: YL
authors.lastname: Chen
authors.forename: Chang-Heng
authors.initials: CH
authors.lastname: Tan
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Tan
authors.forename: Shi-Jin
authors.initials: SJ
authors.lastname: Qu
authors.forename: Shan-Hao
authors.initials: SH
authors.lastname: Jiang
authors.forename: Da-Yuan
authors.initials: DY
authors.lastname: Zhu
mesh_terms: D007536:Isomerism; D008961:Models, Structural; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification*; D031828:Pyrola / Q000737:chemistry*; D044024:Tetralones / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D010936:Plant Extracts; D044024:Tetralones