Planta Med 2008; 74(4): 458-463
DOI: 10.1055/s-2008-1034359
Analytical Studies
Original Paper
© Georg Thieme Verlag KG Stuttgart · New York

A Simple Method to Identify the Unprocessed Strychnos Seeds used in Herbal Medicinal Products

Quan-Bin Han1 , Song-Lin Li1 , Chun-Feng Qiao1 , Jing-Zheng Song1 , Zong-Wei Cai2 , Paul Pui-Hay But3 , Pang-Chui Shaw4 , Hong-Xi Xu1
  • 1Chinese Medicine Laboratory, Hong Kong Jockey Club Institute of Chinese Medicine, Hong Kong, P. R. China
  • 2Department of Chemistry, Hong Kong Baptist University, Hong Kong, P. R. China
  • 3Department of Biology, The Chinese University of Hong Kong, Hong Kong, P. R. China
  • 4Department of Biochemistry, The Chinese University of Hong Kong, Hong Kong, P. R. China
Further Information

Publication History

Received: December 13, 2007 Revised: January 21, 2008

Accepted: February 15, 2008

Publication Date:
26 March 2008 (online)

Abstract

The seeds of Strychnos nux-vomica are popularly used in the treatment of arthritis. Being extremely toxic, the raw seeds are forbidden and must be processed before clinical use. The quality of crude and processed Strychnos seeds can be controlled by examining the toxic alkaloids using established HPLC methods. But this procedure does not work in the case where the seeds are powdered and mixed with other medicinal materials in proprietary production. In this quality control study on Strychnos seeds, the contents of two major toxic alkaloids (strychnine and brucine) and a major non-alkaloid constituent (loganic acid) in twenty-four samples of Strychnos seeds (nine processed and fifteen unprocessed) were compared using published HPLC-UV methods. The results showed that the better the seeds were processed, the less loganic acid was found. The alkaloids and non-alkaloid components simultaneously decreased in processed seeds. The content ratio between alkaloids and loganic acid was clearly different in well-processed and crude Strychnos seeds. Based on this interesting discovery, a simple chromatographic method was established which allows a simultaneous determination of loganic acid and the alkaloids strychnine and brucine. The relative peak area (RPA) of strychnine-to-loganic acid was revealed to be a reliable key quality control parameter in order to effectively identify the processed seeds. This new method has been successfully applied to detect the insufficiently processed Strychnos material in marketed herbal medicinal products.

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Dr. Hongxi Xu

Hong Kong Jockey Club Institute of Chinese Medicine

Shatin

N.T.

Hong Kong

People’s Republic of China

Fax: +852 2603 6263

Email: xuhongxi@hkjcicm.org