Extracting Information from Chromatographic Herbal Fingerprints - - Chromatography Online
Extracting Information from Chromatographic Herbal Fingerprints


LCGC Europe
Volume 21, Issue 9, pp. 438-443

Natural products have served mankind as a source of medicine since — and even before — historical records began. Herbal extracts now play an important and growing role in disease prevention and therapy, and are used extensively as drugs and food additives.

Compared with synthetic chemical drug compounds, the composition of herbal extracts is far more complex. Consequently, their quality control is becoming an increasingly important issue. For example, by the European legislation (directive 2004/24/EC concerning "traditional herbal medicinal products") a more strict control on the quality and purity of these products is required. This is also the case by the State Drug Administration of China. It involves, for example, the creation of a type of monograph as a guideline to test the identity and quality.


Figure 1
Identity and quality can be derived from fingerprint chromatograms. These fingerprints can be defined as "a chromatographic pattern of an herbal extract showing some common pharmacologically active and/or chemical characteristic compounds". An example is shown in Figure 1. The entire fingerprints are used as a source of information because by assaying only a number of compounds from the extract, the total intrinsic quality of the herb is not necessarily assessed.

Another reason for stricter quality control is to assess if other herbs/extracts are used than those expected. This can be a result of conscious adulterations where another plant is sold, to the unconscious mistaken use of "look-alikes".

Confusion can also occur due to language. For example, when translating from Chinese pin-yin terminology into western languages or when the same name is used in different regions for different parts of the plant, or even different species or genera.

An example of such a language confusion resulting in the mistaken use of a herb occurred in the beginning of the 1990s in Belgium. Stephania tetrandra, which is used in a herbal treatment against obesity, was exchanged with Aristolochia fangchi, a herb resulting in a severe nephropathy because of the presence of aristolochic acid. Confusion probably occurred because of the similarity in the pin-yin terminology of both plants: Feng Fangji vs. Guang Fangji, respectively.

The fingerprint chromatograms are also accepted by the World Health Organization (WHO) as an identification and qualification technique for medicinal herbs. There are two main phases of a fingerprint approach:

  • The development of the fingerprint.
  • The extraction of information.

Analysis and handling of the fingerprint data is, therefore, an important aspect.

Fingerprint Development

The main separation technique used in fingerprint development is high-performance liquid chromatography (HPLC) coupled to ultraviolet (UV), electric light scattering (ELS) and, occasionally, mass spectrometry (MS) detection. For fingerprint development, spectroscopic techniques, such as near infra-red (NIR), Raman, nuclear magnetic resonance spectroscopy (NMR), and other separation techniques, including thin layer chromatography (TLC) and capillary electrophoresis (CE) can also be used.


ADVERTISEMENT

blog comments powered by Disqus
LCGC E-mail Newsletters
Global E-newsletters subscribe here:




 

LCGC COLUMNISTS 2014

Sample Prep Perspectives | Ronald E. Majors:

LCGC Columnist Ron Majors, established authority on new column technologies, keeps readers up-to-date with new sample preparation trends in all branches of chromatography and reviews developments in existing technology lines.

LATEST: The Role of Selectivity in Extractions: A Case Study

History of Chromatography | Industry Veterans:

With each installment of this column, a different industry veteran covers an aspect of the evolution and continued development of the science of chromatography, from its birth to its eventual growth into the high-powered industry we see today.

LATEST: Georges Guiochon: Separation Science Innovator

MS — The Practical Art| Kate Yu:
Kate Yu is the editor of 'MS-The Practical Art' bringing her expertise in the field of mass spectrometry and hyphenated techniques to the pages of LCGC. In this column she examines the mass spectrometric side of coupled liquid and gas-phase systems. Troubleshooting-style articles provide readers with invaluable advice for getting the most from their mass spectrometers.

LATEST: Mass Spectrometry for Natural Products Research: Challenges, Pitfalls, and Opportunities


LC Troubleshooting | John Dolan:

LC Troubleshooting sets about making HPLC methods easier to master. By covering the basics of liquid chromatography separations and instrumentation, John Dolan, Vice President of LC Resources and world renowned expert on HPLC, is able to highlight common problems and provide remedies for them.

LATEST: LC Method Scaling, Part I: Isocratic Separations

More LCGC Chromatography-Related Columnists>>

LCGC North America Editorial Advisory Board>>

LCGC Europe Editorial Advisory Board>>

LCGC Editorial Team Contacts>>


Source: LCGC Europe,
Click here