Abstract
The
fast developing international trade of products based on traditional
knowledge and their value chains has become an important aspect of the
ethnopharmacological debate. The structure and diversity of value chains
and their impact on the phytochemical composition of herbal medicinal
products, as well as the underlying government policies and regulations,
have been overlooked in the debate about quality problems in
transnational trade. Rhodiola species, including Rhodiola rosea L. and
Rhodiola crenulata (Hook. f. & Thomson) H. Ohba, are used as
traditional herbal medicines. Faced with resource depletion and
environment destruction, R. rosea and R. crenulata are becoming
endangered, making them more economically valuable to collectors and
middlemen, and also increasing the risk of adulteration and low quality.
Rhodiola products have been subject to adulteration and we recently
assessed 39 commercial products for their composition and quality.
However, the range of Rhodiola species potentially implicated has not
been assessed. Also, the ability of selected analytical techniques in
differentiating these species is not known yet. Using a strategy
previously developed by our group, we compare the phytochemical
differences among Rhodiola raw materials available on the market to
provide a practical method for the identification of different Rhodiola
species from Europe and Asia and the detection of potential adulterants.
Nuclear magnetic resonance spectroscopy coupled with multivariate
analysis software and high performance thin layer chromatography
techniques were used to analyse the samples. Rosavin and rosarin were
mainly present in R. rosea but also in Rosea sachalinensis Borris. 30%
of the Rhodiola samples purchased from the Chinese market were
adulterated by other Rhodiola spp. The utilization of a combined
platform based on 1H-NMR and HPTLC methods resulted in an integrated
analysis of different Rhodiola species. We identified adulteration at
the earliest stage of the value chains, i.e., during collection as a key
problem involving several species. This project also highlights the
need to further study the links between producers and consumers in
national and trans-national trade
