title: Preparative isolation of aldose reductase inhibitory compounds from Nardostachys chinensis by elution-extrusion counter-current chromatography.
abstract: A method combining enzyme assay-guided high-performance liquid chromatography (HPLC) micro-fractionation and elution-extrusion counter-current chromatography (EECCC) was developed to screen and separate aldose reductase (AR) inhibitory activities from those of the ethyl acetate (EtOAc) fraction of Nardostachys chinensis. Under the target-guidance of HPLC micro-fractionation, two phenolic compounds, three caffeoylquinic acid derivatives and two sesquiterpene were isolated by high-speed countercurrent chromatography (HSCCC) using elution modes of extrusion-elution. A one-step HSCCC isolation method was developed, which included a solvent system of n-hexane-EtOAc-methanol-water at a ratio of 2:8:3:7 (v/v/v/v). The chemical structures of the isolated compounds were determined using (1)H- and (13)C-nuclear magnetic resonance spectrometry. The compounds inhibiting AR in the EtOAc fraction of 70 % ethanol extracts of N. chinensis were identified as chlorogenic acid (2) and 1,5-di-O-caffeoylquinic acid (6). Our results indicate that the combined method of HPLC micro-fractionation and EECCC is fast, efficient, and reproducible for systematically isolating AR inhibitory compounds from complex natural products.
authors.affiliation: Department of Food Science and Nutrition, Hallym University, Chuncheon, 200-702, Korea.
authors.forename: Ji Hun
authors.initials: JH
authors.lastname: Paek
authors.forename: Soon Sung
authors.initials: SS
authors.lastname: Lim
mesh_terms: D000449:Aldehyde Reductase / Q000037:antagonists & inhibitors*; D000818:Animals; D005591:Chemical Fractionation; D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D015394:Molecular Structure; D032404:Nardostachys / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D011801:Quinic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D051381:Rats; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D010636:Phenols; D010936:Plant Extracts; D012717:Sesquiterpenes; C472707:caffeoylquinic acid; D011801:Quinic Acid; D000449:Aldehyde Reductase