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Primary and Secondary Evaluation of Method SJW-15
SJW-15:
Simultaneous Determination of Total Hypericin and Hyperforin in St. John’s wort
Extracts by HPLC with Electrochemical Detection
Author(s):
Phytochem. Anal. 18: 204–208 (2007), Ulla Rückert, Werner Likussar And Astrid
Michelitsch*
S
UMMARY OF
M
ETHOD
:
G
ENERAL
C
OMMENTS
:
This method allows for simultaneous analysis of hypericin and hyperforin. The detection is accomplished
with electrochemical detector and quantification performed using external standards of hypericin and
hyperforin. St. John’s wort extract and a finished product (90 mg) are extracted with 50 mL of ethanol
and water solution (80:20 v/v) via sonication, filtered and frozen, all performed while protected from
light. Samples are thawed, placed into amber vials and exposed to 380-700 nm light for 30 minutes. The
resulting sample is diluted with methanol in a ratio of 1:10 (v/v) and analyzed by HPLC. The
chromatographic separation is achieved isocratically on a RP-18 column (125 x 4 mm i.d.; 5um) with 10%
ammonium acetate: acetic acid buffer (0.5 M: pH 3.7), methanol and acetonitrile (10:40:50 v/v/v). Flow
rate of 0.8 mL/min. Run time is 15 min.
P
ROS
/S
TRENGTHS
:
This method allows for simultaneous analysis of hypericin and hyperforin with a short run time. The
sample preparation is straight forward, although light-protection required. EC detector is relatively in
expensive.
C
ONS
/W
EAKNESSES
:
This method does not detect or quantify the flavonoids. Many SLV parameters were not evaluated.
EXPERT REVIEW PANEL VOTE
AND
RECOMMENDATION
MOTION: Not to consider this method for First Action Official Method status.
Brown, Schaneberg (Unanimous) Motion Passed
ERP PROFILE SUMMARIES
97