Simultaneous determination of total hypericin and hyperforin in St. John's wort extracts by HPLC with electrochemical detection.
An analytical procedure was developed for the simultaneous determination of total hypericin (protopseudohypericin, pseudohypericin, protohypericin and hypericin) and hyperforin in Hypericum perforatum (St. John's wort) extracts and its preparations. The determination of total hypericin and hyperforin in one step was achieved by exposing the samples to artificial daylight in amber glass vials. This procedure allows both the photoconversion of the protoforms into the appropriate hypericins and the protection of the photosensitive hyperforin. For quantification, an HPLC method with electrochemical detection was applied. As an example of the application of the principle, two preparations containing St. John's wort were assayed.
Rückert
Ulla
U
Institut für Pharmazeutische Wissenschaften, Karl-Franzens-Universität Graz, Schubertstrasse 1, A-8010 Graz, Austria.
Likussar
Werner
W
Michelitsch
Astrid
A
D000873:Anthracenes; D000928:Antidepressive Agents / Q000737:chemistry; D001643:Bridged Bicyclo Compounds / Q000032:analysis / Q000737:chemistry / Q000528:radiation effects; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004563:Electrochemistry / Q000379:methods*; D020902:Hypericum / Q000737:chemistry*; D008027:Light; D010569:Perylene / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000528:radiation effects; D010696:Phloroglucinol / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000528:radiation effects; D010936:Plant Extracts / Q000737:chemistry; D011208:Powders / Q000737:chemistry; D013607:Tablets / Q000737:chemistry; D013729:Terpenes / Q000032:analysis* / Q000737:chemistry / Q000528:radiation effects
D000873:Anthracenes; D000928:Antidepressive Agents; D001643:Bridged Bicyclo Compounds; D010936:Plant Extracts; D011208:Powders; D013607:Tablets; D013729:Terpenes; D010569:Perylene; C004965:hypericin; D010696:Phloroglucinol; C001654:hyperforin