Rhizoma Smilacis Glabrae (RSG), belonged to Liliaceae family, smilax genera, is a commonly used traditional Chinese
medicine for detoxication and diuresis. It is the principal medicine used for the
treatment of syphilis in ancient China. Besides, it is also used for skin problems,
such as psoriasis and chronic eczema. The extract of this herb is also the main
ingredient in turtle jelly, which is a functional food consumed
popularly in Hong Kong and in Southern China. However, there are many confusable
species of RSG existed in the market.
These include Rhizoma Smilacis Chinae, Rhizoma Heterosmilacis etc. In some
regions of China, these herbs have been given the
same Chinese name and are confusedly used. However,
using a counterfeit or poor quality herb will decrease the clinical effects and may even
result in life-threatening
poisoning. Hence, it is necessary to establish a reliable method for
distinguishing these confusing species from RSG.
Fig.1: Standard fingerprint of RSG generated by
means of simulation of all tested sample. The upper right hand side is a picture of RSG.
A photo of Dr HY Cheung’s Research Team
In our study, a high performance
liquid chromatographic (HPLC) chromatogram has been developed.
This chromatogram could be used as the fingerprint and
quantitative means for the quality control of RSG. It was found that
nine peaks were identified in the chromatogram of RSG using an
online diode array detector (DAD) and an electrospray ionization
tandem mass spectrometer (ESIMS/MS). These nine components
were 3-O-caffeoylshikimic acid, taxifolin, engeletin,
isoengeletin, resveratrol, astilbin and its three isomers.
With the help of this chromatogram, the content of these
nineconstitutes were quantitatively determined. Among
them, 6 constitutes were consistently found in 18 batches
samples and a standard fingerprint of RSG was generated by means of simulating
the 18 tested samples (Fig.1). Using this standard fingerprint,
RSG can be easily
distinguished from other confusing species, such as
Rhizoma Smilacis Chinae and Rhizoma
Heterosmilacis. Hence, the
fingerprint and assay method developed should have significant impact on the
quality control of RSG and its derived products. It will also be useful for the
pharmacokinetic study of the herb.
Dr Hon-yeung CHEUNG
Department of Biology & Chemistry
City University of Hong Kong