Rapid and Non-Destructive Determination of the Echinacoside Content in Echinacea Roots by ATR-IR and NIR Spectroscopy

Abstract

NIR reflection and ATR-IR spectroscopy methods are developed to determine the echinacoside content in roots of Echinacea angustifolia and Echinacea pallida. Based on the recorded spectra and the HPLC reference data, chemometrical analyses are performed using a partial least squares (PLS) algorithm. Generally, good calibration statistics are obtained for the prediction of the echinacoside content presenting comparatively high coefficients of determination (R²) and low root mean standard errors of cross validation (RMSECV). It is demonstrated that optimal predictions are possible when using a dispersive spectrometer covering the spectral range from 1100 to 2500 nm. In contrast to the time-consuming HPLC method, the described non-destructive measurements allow us to predict the echinacoside content already after an analysis time of approx. one minute. Both spectroscopic techniques presented in this paper are shown to be useful in agricultural practice as well as in the phytopharmaceutical industry.

Echinacea - Asteraceae - echinacoside content - near-infrared spectroscopy (NIRS) - ATR-IR spectroscopy

References

• 1 Bauer R, Remiger P, Wagner H. Echinacea .  Dtsch Apoth Ztg. 1988;  128 174-80
• 2 Bauer R. Echinacea containing drugs - Effects and active constituents.  Z Ärztliche Fortbild. 1996;  90 111-5
• 3 Bauer R, Wagner H. Echinacea species as potential immunostimulatory drugs. In: Economic and Medicinal Research, Wagner H, Farnsworth NR, editors.  Academic Press Inc, San Diego, CA (USA),. 1991;  5 253-321
• 4 Mazza G, Cottrell T. Volatile components of roots, stems, leaves and flowers of Echinacea species.  J Agric Food Chem. 1999;  47 3081-5
• 5 Lienert D, Anklam E, Panne U. Gas chromatography-mass spectral analysis of roots of Echinacea species and classification by multivariate data analysis.  Phytochem Anal. 1998;  9 88-98
• 6 Facino R M, Carini M, Aldini G, Saibene L, Pietta P, Mauri P. Echinacoside and caffeoyl conjugates protect collagen from echinacea extracts in the prevention of skin photodamage.  Planta Med. 1995;  61 510-4
• 7 Anonymus Monograph-draft ”Pale coneflower root” and ”Pale coneflower herb”. Pharmeuropa 2002 14: No. 1
• 8 Hu C, Kitts D D. Studies on the antioxidant activity of Echinacea root extract.  J Agric Food Chem. 2000;  48 1466-72
• 9 Bauer R, Puhlmann J, Wagner H. Immunologische In-vivo und In-vitro-Untersuchungen mit Echinacea-Extrakten.  Arzneimittelforschung (Drug Res.). 1988;  38 276-81
• 10 Blaschek W, Schütz M, Kraus J, Franz G. In vitro production of specific polysaccharides: isolation and structure of an antitumor active β-glucan from Phytophthora parasitica .  Food Hydrocolloids. 1987;  1 371-80
• 11 Schulz H, Steuer B, Krüger H, Schütze W. Möglichkeiten und Grenzen NIR-spektroskopischer Qualitätsbestimmung pflanzlicher Drogen.  Z Arzn Gew Pfl. 2001;  6 138-42
• 12 Schulz H, Steuer B, Krüger H. Rapid near infrared spectroscopic prediction of secondary metabolites in tea drugs and spice plants.  In: Proc. 9^th Int. Conference on NIRS in Verona. Davies AMC, Giangiacomo R, editors NIR Publications Chichester, West Sussex (UK),; 2000: 447-53
• 13 Harrick N J. Internal reflection spectroscopy. Interscience Publ New York/London/Sidney,; 1967
• 14 Mirabella F M, Harrick N J. Internal Reflection Spectroscopy: Review and Supplement. Harrick Scientific Corp Ossening, New York; 1985
• 15 Coates J P, Sanders A. A universal sample handling system for FT-IR spectroscopy.  Spectroscopy Europe. 2000;  5 12-22