HPLC Applications for Traditional Chinese Medicines (Part I)
One of the exciting areas in drug discovery in recent times has been the discovery and acceptance of new ways to treat various illnesses with ancient medicines from countries such as China and India. These medicines are derived from natural sources--plants and animals--and, in some instances, have been in use for a couple of thousand years (for example, ginseng).
The focus is is on identifying active ingredients found in these age-old remedies for everything from influenza to malaria to cancer. For example, in the case of ginseng, while we might be familiar with the energy-boosting qualities of ginseng, Chinese clinical trials of notoginseng (called Sanqi or Tianqi in China) have demonstrated its efficacy in promoting blood circulation, removing blood stasis (including blood clotting), relieving swelling, and alleviating pain.
Here, we present several high pressure liquid chromatography (HPLC) applications designed for the analysis of traditional Chinese medicines in two blogs posts. This first post covers wild chrysanthemum, ginkgo biloba, and ginseng.
Application Note 207, Chromatographic Fingerprinting of Flos Chrysanthema Indici Using HPLC, (downloadable PDF) discusses the use of accelerated solvent extraction (ASE) and HPLC technology to determine the content of chlorogenic acid and linarin in wild chrysanthemum. It is believed to improve eyesight and cure fever, swelling, skin infections, sore throats, and headaches. The Chinese Pharmacopeia Edition 2005 (CP 2005) regulates its use as an herbal medicine and only the flower of Flos chrysanthemi indici, Dendranthema indicum L. (D. indicum) is used in medicinal preparations. The application summarizes the analysis of 20 samples from different parts of China.
This poster note titled, Determination of the Composition of Natural Products by HPLC with Charged Aerosol Detection, (downloadable PDF) discusses the measurement of analytes in ginkgo biloba (reputed to have energizing benefits) and ginseng (used for memory enhancement among many other uses) using an isocratic and gradient HPLC with Charged Aerosol Detection (CAD). The advantage of this method is that the analytes showed consistent response independent of chemical structure (typically < 10% variability between compounds).
While we are on the subject of ginkgo biloba, in case you are interested, here is a study titled, Development, optimization and validation of a fingerprint of Ginkgo biloba extracts by high-performance liquid chromatography, on the National Institute of Health website.
AN 192: Rapid Analysis of Ginseng Using Accelerated Solvent Extraction and High Performance Liquid Chromatography, (downloadable PDF) describes the use of our ASE system, which requires only 15 mins for the extraction of ginsenoside. In comparison, conventional extraction methods, such as sonication, hot reflux, soxhlet, and immersion can require 2-14 hours. In this application note, the method combines the ASE extraction with a 25 min HPLC separation for the analysis of 15 ginsenosides. This method is suitable for analyzing Asian ginseng, American ginseng, and notoginseng.
Next post on more applications for the analysis of Chinese medicines.