Identification of medicinal plants in pharmaceutical products using ITS sequences and metabolomic fingerprinting

Quality control is a basic requirement in the manufacturing of herbal medicinal products. In the past, sequencing of the ITS (Internal Transcribed Spacer) region proved to be a promising attempt in the process of identifying plant material [1]. Additionally, metabolomic fingerprinting with NMR in combination with PCA (Principal Component Analysis) turned out to be an alternative method for assuring quality [2] and origin [3] and the discrimination between species [4]. Because of new legislation opening the European market to TCM products a part of our research is focused on plant species from this tradition-based therapeutic system.

During this study, a database consisting of ITS-sequences for a series of TCM drugs could be established. Several of them were also analysed concerning their metabolomic profiles. As case study, samples of the raw drugs and granulates of Arctii Fructus, Artemisiae annuae Herba and Asteris Radix were analysed. It was possible to clearly identify the raw drugs by means of their ITS-sequences and metabolomic fingerprints. The metabolomic fingerprints of granulates differed from those of the raw drugs because of additional substances, particularly corn starch. Indeed, it was possible to isolate DNA from the granulates, but first attempts to sequence the ITS region turned out to be challenging as it is likely that also DNA from corn starch was isolated, i.e. making cloning necessary.

Acknowledgement: We thank the Federal Institute for Drugs and Medical Devices for financial support.

References: 1. Baldwin, B.G. et al. (1995) Ann Missouri Bot Gard 82:247–277. 2. Le Gall, G. et al. (2004)J Agric Food Chem 52:692–700 3. Wang, Y. et al. (2004) Planta Med 70: 250–255. 4. Choi, Y.H. et al. (2005)J Agric Food Chem 53:1237–1245