Infrared authentication of ginseng species: the use of the 2-6PC rule.

The quality of herbal products is important for ensuring efficacy and consumer safety. Traditional methods of authenticating herbs like ginseng via their morphology are hardly reliable. Different chemical constituents in herbs like ginseng tend to exhibit characteristic IR fingerprints that enable their identification. We previously introduced an IR-based protocol known as the "2-6PC rule" to categorize and identify ginseng and its products, as well as distinguishing it from morphological fakes. Here, we describe the use of this rule as a rapid and effective means of analyzing the IR spectral fingerprints of the biologically active components of ginseng, as well as distinguishing among its species. Our results show that Panax ginseng, P. quinquefolius, and P. notoginseng can be differentiated from each other. Our results also indicate the presence of starch, carbohydrates, calcium oxalate, and ginsenosides Re and Rg1 in commercial ginseng roots sold in Singapore. This work effectively demonstrates the usefulness of the 2-6PC rule as a rapid screening tool in the authentication of ginseng species.