Planta Med 2007; 73 - P_252
DOI: 10.1055/s-2007-987033

NMR studies found that a commercially supplied standard reference purported to be Withanolide D was instead Withanolide A

K Penman 1, KM Bone 2, P Hayes 3, J De Voss 3, A Agarwal 4, B Murali 4, D Mundkinajeddu 4, A Mayachari 4, R Shenoy 4, RP Lehmann 1
  • 1Mediherb Research Laboratories 3/85 Brandl St Eight Mile Plains Brisbane, 4113, Australia
  • 2School of Health Science, University of New England, Armidale, 2031 Australia
  • 3School of Molecular and Microbial Sciences, The University of Queensland, Brisbane, 4072, Australia
  • 4Natural Remedies Pty Ltd 5B Veerasandra Indl. Area 19
  • thKM Stone, Hosur Road Bangalore 560100 India

Formal and accurate identification of a number of withanolides in the HPLC-PDA traces of Withania somnifera samples was required as part of the development of a routine assay for samples of this herb.

A large number of withanolides have been isolated from Withania somnifera, many with only minor structural differences between them. Sophisicated NMR techniques provide the best approach for the discrimination of these similar compounds [1,2,3] and this approach was used to elucidate the structural differences as well as confirm the identities of commercially available reference compounds. Detection of an incorrectly assigned reference material was made. NMR data proved that the Withanolide D (structure 1) standard was in fact Withanolide A (structure 2). This work reinforces the importance of applying rigorous checks to reference materials.

References: [1] Gottlieb, H. et al. (1981) Org. Mag. Res. 16(1):20–25. [2] Gamoh, K. et al. (1984) J.Chem.Soc. Perkin Trans.1: 449–454. [3] Pelletier, S. et al. (1979) J. Nat. Prod. 42(5): 512–521.

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