title: Absolute configuration determination of angular dihydrocoumarins from Peucedanum praeruptorum.
abstract: From Peucedanum praeruptorum, one new khellactone ester (3'R)-O-acetyl-(4'S)-O-angeloylkhellactone (3), as well as four known angular dihydropyranocoumarins (1, 2, 4, 5) have been isolated. On the basis of NMR spectra and X-ray crystallography, their structures were determined. We have elucidated their absolute configuration by either chiral separation of their alkaline hydrolysis products with Rp-18 HPLC eluted with 5% hydroxypropyl-beta-cyclodextrin (beta-HCD) or by measurement of their CD spectra. A general rule relating the position and absolute streochemistry of the khellactone esters to the sign of their Cotton effects in CD curves is proposed.
authors.affiliation: Department of Natural Medicinal Chemistry, School of Pharmaceutical Sciences, Shandong University, Jinan 250012, China. louhongxiang@sdu.edu.cn
authors.forename: Hong-Xiang
authors.initials: HX
authors.lastname: Lou
authors.forename: Long-Ru
authors.initials: LR
authors.lastname: Sun
authors.forename: Wen-Tao
authors.initials: WT
authors.lastname: Yu
authors.forename: Pei-Hong
authors.initials: PH
authors.lastname: Fan
authors.forename: Lei
authors.initials: L
authors.lastname: Cui
authors.forename: Yan-Hui
authors.initials: YH
authors.lastname: Gao
authors.forename: Bin
authors.initials: B
authors.lastname: Ma
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Ren
authors.forename: Mei
authors.initials: M
authors.lastname: Ji
mesh_terms: D019661:Apiaceae; D002851:Chromatography, High Pressure Liquid; D003374:Coumarins / Q000737:chemistry*; D006801:Humans; D008968:Molecular Conformation; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry*; D018517:Plant Roots; D014961:X-Ray Diffraction
chemical_list: D003374:Coumarins; D010936:Plant Extracts