title: An HPLC method to determine sennoside A and sennoside B in Sennae fructus and Sennae folium.
abstract: BACKGROUND
  The current Ph. Eur. monographs for senna pods, senna leaf and senna leaf dry extract standardised describe a photometric assay based on the Bornträger reaction to determine hydroxyanthracene glycosides, calculated as sennoside B. The method is timeconsuming, unspecific for sennosides and the precision is not adequate for a modern assay.
  
  
  OBJECTIVE
  The photometric method shall therefore be replaced by a modern HPLC method. About 70 % of the total anthrachinone content in herbal drugs of senna species is due to sennoside A and sennoside B. These substances are therefore suitable for the standardisation of Senna products. The Japanese Pharmacopoeia (JP) already describes an HPLC method to determine sennoside A and sennoside B in the monograph for senna leaf. It uses ion-pair chromatography with tetraheptylammoniumbromide. The procedure described in the monograph has a runtime of 70 min.
  
  
  METHODS
  The adapted and validated method described here uses solid-phase extraction (SPE) which allows a selective sample preparation by using an anion exchange phase. A conventional RP C18 column Tosh TSKgel ODS-80TS (4.6 mm × 150 mm), 5 μm, was used as stationary phase and acetonitrile for chromatography R, water R, phosphoric acid R (200:800:1 V/V/V) as mobile phase. The flow rate was 1.2 mL/min, the column temperature 40 °C, the detection wavelength 380 nm, and the injection volume 20 μL. The runtime is 10 min, the chromatogram shows 2 peaks due to sennoside A/B and 2 additional smaller compounds. One of them is rhein-8-O-glucoside.
  
  
  RESULTS
  The procedure has been successfully validated according to ICH guidelines. We analysed 6 batches of Senna. The pods (Senna angustifolia) showed a total content of sennoside A and B of 1.74-2.76 % m/m and the content of senna leaves was clearly lower with 1.07-1.19 % m/m, respectively.
  
  
  CONCLUSIONS
  The suggested method is considered to be suitable to determine sennoside A and sennoside B in senna leaves and senna pods. The consideration is based on the performed validation and on the results for the analysed samples. A short run time and better resolution are clear advantages of the suggested method, compared to other methods.
authors: Zurich University of Applied Science, Institute of Biotechnology, Research Group of Phytopharmacy, Einsiedlerstrasse 31, 8820 Wädenswil, Switzerland, immanuel.rosenthal@gmail.com.
authors: Immanuel
authors: I
authors: Rosenthal
authors: Zurich University of Applied Science, Institute of Biotechnology, Research Group of Phytopharmacy, Einsiedlerstrasse 31, 8820 Wädenswil, Switzerland, wola@zhaw.ch.
authors: Evelyn
authors: E
authors: Wolfram
authors: Zurich University of Applied Science, Institute of Biotechnology, Research Group of Phytopharmacy, Einsiedlerstrasse 31, 8820 Wädenswil, Switzerland, mier@zhaw.ch.
authors: Beat
authors: B
authors: Meier
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D018515:Plant Leaves / Q000737:chemistry; D012676:Senna Extract / Q000032:analysis*; D029846:Senna Plant / Q000737:chemistry*; D000081226:Sennosides; D012680:Sensitivity and Specificity
chemical_list: D000081226:Sennosides; D012676:Senna Extract
keywords: HPLC; senna leaf; senna pods; sennoside A; sennoside B; validation