title: Enantioseparation and absolute configuration determination of angular-type pyranocoumarins from peucedani radix using enzymatic hydrolysis and chiral HPLC-MS/MS analysis.
abstract: Angular-type pyranocoumarins from Peucedani Radix (Chinese name: Qian-hu) have exhibited potential for use on treatment of cancer and pulmonary hypertension. Due to the existence of C-3' and C-4' chiral centers, compounds belonging to this chemical type commonly exist in enantiomers and/or diastereoisomers, which may elicit distinct activities during their interactions with the human body. In the present study, a new method, which combines enzymatic hydrolysis with chiral LC-MS/MS analysis, has been developed to determine the absolute configurations of these angular-type pyranocoumarins. Pyranocoumarins isolated from Qian-hu, their enantiomers, or metabolites were individually incubated with rat liver microsomes. As the common end product from enzymatic hydrolysis of all tested pyranocoumarins, cis-khellactone was collected and its absolute configuration was determined by comparison with (+)-cis-khellactone and (-)-cis-khellactone using chiral LC-MS/MS. The absolute configurations of all tested parent pyranocoumarins were determined by combination of LC-MS/MS, NMR and polarimetric analysis. The results revealed that the metabolite cis-khellactone retained the same absolute configurations of the stereogenic carbons as the respective parent compound. This method was proven to be rapid and sensitive and also has advantages in discriminating single enantiomers and mixtures of optical isomers with different ratios.
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macao SAR 999078, China.
authors.forename: Yue-Lin
authors.initials: YL
authors.lastname: Song
authors.forename: Qing-Wen
authors.initials: QW
authors.lastname: Zhang
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Li
authors.forename: Ru
authors.initials: R
authors.lastname: Yan
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Wang
mesh_terms: D000818:Animals; D019661:Apiaceae / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006868:Hydrolysis; D019906:Nuclear Magnetic Resonance, Biomolecular; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry; D039681:Pyranocoumarins / Q000032:analysis / Q000737:chemistry*; D051381:Rats; D053719:Tandem Mass Spectrometry
chemical_list: D010936:Plant Extracts; D039681:Pyranocoumarins