Differentiation for closely related botanical species by pharmacopeial monographs

To distinguish the closely related botanical species, selective analytical procedures in the pharmacopeial monographs are used to reduce the possibility of adulteration by substitutes with potential confounders. In this work, we present the differentiations between Rhodiola crenulata Root and Rhizome and R. rosea Root and Rhizome, as well as the differentiations between Citrus reticulata Pericarp and C. maxima Pericarp based on the monographs developed for Rhodiola crenulata Root and Rhizome [1], R. rosea Root and Rhizome [2] and Citrus reticulata Pericarp [3]. Both R. crenulata Root and Rhizome and R. rosea Root and Rhizome contain salidroside and tyrosol but R. rosea Root and Rhizome also contains rosavin and rosarian. With the HPTLC method [1], no rosavin band was observed in R. crenulata Root and Rhizome while rosavin band was observed in R. rosea Root and Rhizome sample solution. With the HPLC method [2], R. rosea Root and Rhizome displayed peaks of salidroside, tyrosol, rosavin and rosarian; R. crenulata Root and Rhizome only displayed salidroside and tyrosol, no rosavin and rosarian peaks were observed. Both C. reticulata Pericarp and C. maxima Pericarp contain dihydroflavone glycosides, however, C. reticulata Pericarp mainly contain hesperidin and C. maxima Pericarp mainly contain naringin. With the HPTLC and HPLC methods [3], these two species could be distinguished due to hesperidin and naringin with different retention times and R _F values. Orthogonality between HPLC and HPTLC technics can provide greater assurances for botanical identification than the application of only one of these procedures. The combination of traditional morphological, microscopic and modern chromatographic procedures in the identification sections of the monographs can efficiently distinguish the closely related botanical species materials.

Acknowledgements: 1. State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China; 2. Department of Pharmaceutical Analysis, Shenyang Pharmaceutical University, Shenyang, China; 3. CAMAG Laboratory.

Keywords: Quality control of herbal products, USP monograph, Rhodiola crenulata root and rhizome, Rhodiola rosea root and rhizome, Citrus reticulata pericarp.

References:

[1] Rhodiola crenulata root and rhizome. Technical tips online. Available at http://hmc.usp.org

[2] Rhodiola rosea root and rhizome. Technical tips online. Available at http://hmc.usp.org

[3] Citrus reticulata pericarp. Technical tips online. Available at http://hmc.usp.org