Planta Med 2019; 85(18): 1457
DOI: 10.1055/s-0039-3400105
Main Congress Poster
Poster Session 1
© Georg Thieme Verlag KG Stuttgart · New York

HPTLC identity testing for Rhamni purshianae cortex and isolation of Cascarosides B, C and D as reference compounds

S Peter
1   Institute of Chemistry and Biotechnology, Zürich University of Applied Sciences,, Wädenswil, Switzerland
,
BNK Abdelmalek
1   Institute of Chemistry and Biotechnology, Zürich University of Applied Sciences,, Wädenswil, Switzerland
,
C Demuth
1   Institute of Chemistry and Biotechnology, Zürich University of Applied Sciences,, Wädenswil, Switzerland
,
B Meier
1   Institute of Chemistry and Biotechnology, Zürich University of Applied Sciences,, Wädenswil, Switzerland
,
E Wolfram
1   Institute of Chemistry and Biotechnology, Zürich University of Applied Sciences,, Wädenswil, Switzerland
› Author Affiliations
Further Information

Publication History

Publication Date:
20 December 2019 (online)

 

Rhamni purshianae cortex is the herbal drug from the bark of Frangula purshiana Cooper, which is native to the Pacific coast of North America and has been traditionally used for treatment of constipation. The characteristic constituents of this laxative herbal drug are anthraquinones, oxanthrones, anthranols and anthrones . The herbal drug should not contain less than 8% hydroxyanthracene glycosides [1], of which 60-70% are cascarosides, mixed anthrone-C- and O-glycosides [2].

The aim of this study was to develop a suitable HPTLC method for revision of identity testing in the Cascara monograph of the European Pharmacopoeia [1].

The mobile phase water:methanol:ethyl acetate:acetic acid (19:21:90:2 v/v) was found optimal among twelve test solvents on normal phase HPTLC to get sharp bands of cascarosides A, B, C and D and a System Suitability Test with 50 g/l KOH in ethanol 50% v/v as derivatizing agent. Selectivity of the method for Rhamni purshianae cortex in comparison to Frangula alnus Mill., as a closely related herbal drug is demonstrated. Adulteration is not reported as being common. Since only cascaroside A is commercially available, cascarosides B, C and D were isolated. DryLab4 software (Molnar Institute Berlin) was used to develop an UHPLC -DAD-MS method for identification of cascarosides through their UV and mass spectra by comparison with data in [3].

The study demonstrates a method, which is proposed for adoption into the Ph. Eur. and provides for separation and location of cascarosides A-D on the HPTLC fingerprint.

 
  • References

  • 1 EDQM. Cascara, Rhamni purshianae cortex. Monograph 20825. In: European Pharmacopoeia (Ph.Eur.). 9th edition.. Strasbourg: Council of Europe; 2016
  • 2 ESCOP. Rhamni purshianae cortex - Cascara. Exeter: ESCOP; 2015
  • 3 Demarque DP, Pinho DR, Callejon DR, de Oliveira GG, Silva DB, Carollo CA, Lopes NP. New cascarosides from Rhamnus purshiana and fragmentation studies of the class by IT-MS. Rapid Commun Mass Spectrom 2017; 31: 1169-1174