Rapid and efficient purification of naphthodianthrones from St. John's wort extract by using liquid-liquid extraction and SEC.
Hypericin and pseudohypericin, the main naphthodianthrones present in Hypericum species are among the most promising natural products, but the research concerning their biological activities is hindered by their low content in the plant. In this paper a method for the rapid isolation of hypericin and pseudohypericin from Hypericum perforatum hydro-alcoholic dried extracts has been developed. Briefly, the method consists of a partition of the extract between organic and aqueous layers and further purification of the richest extract in naphthodianthrones with Sephadex LH-20 column chromatography. A final separation of hypericin from pseudohypericin was achieved using Sephadex LH-60 column chromatography. All partitions were carried out in triplicate and monitored by LC-MS and NMR analyses. The best results were obtained by successive extraction with n-hexane, Et(2)O and EtOAc. A three-step fractionation resulted in 98% content in total naphthodianthrones. To the best of our knowledge this is the first report on the separation of hypericin from pseudohypericin using size exclusion chromatography.
Department of Pharmaceutical Sciences, University of Florence, Polo Scientifico, Sesto Fiorentino, Florence, Italy. anastasiakarioti@yahoo.it
Anastasia
A
Karioti
Franco F
FF
Vincieri
Anna R
AR
Bilia
D000085:Acetates / Q000737:chemistry; D000873:Anthracenes; D002850:Chromatography, Gel; D003911:Dextrans / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000302:isolation & purification; D006586:Hexanes / Q000737:chemistry; D020902:Hypericum / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D000432:Methanol / Q000737:chemistry; D010569:Perylene / Q000031:analogs & derivatives* / Q000302:isolation & purification*; D010936:Plant Extracts / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry
D000085:Acetates; D000873:Anthracenes; D003911:Dextrans; D004791:Enzyme Inhibitors; D006586:Hexanes; D010936:Plant Extracts; D012997:Solvents; D014867:Water; C026385:n-hexane; D010569:Perylene; C007650:ethyl acetate; C004965:hypericin; C040462:sephadex, 2-hydroxypropyl ether; C056602:pseudohypericin; D000432:Methanol