Absolute configuration determination of angular dihydrocoumarins from Peucedanum praeruptorum.
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.
Lou
Hong-Xiang
HX
Department of Natural Medicinal Chemistry, School of Pharmaceutical Sciences, Shandong University, Jinan 250012, China. louhongxiang@sdu.edu.cn
Sun
Long-Ru
LR
Yu
Wen-Tao
WT
Fan
Pei-Hong
PH
Cui
Lei
L
Gao
Yan-Hui
YH
Ma
Bin
B
Ren
Dong-Mei
DM
Ji
Mei
M
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
D003374:Coumarins; D010936:Plant Extracts