Determination of chlorogenic acid in Eucommia ulmoides Oliver extracts by near-infrared spectroscopy

Eucommia ulmoides Oliver shows various medicinal functions in both in-vitro and in-vivo studies, and its chlorogenic acid component has been indicated as one of the major bioactive compounds exerting pharmacological effects. At present, the high-performance liquid chromatography technique is the conventional method used for the quantification of chlorogenic acids, but it requires expensive instrumentation and complicated operation. In the current research, near-infrared spectroscopy was employed for the quantitative analysis of chlorogenic acid in Eucommia ulmoides. The quantification model was established based on near-infrared spectroscopy spectra for analysis of chlorogenic acids in the ethanol-aqueous extract from Eucommia ulmoides leaf. A partial least squares regression was employed for the quantitative model development and test validation was adopted to validate the regression model. The optimized ranges for the quantitative model are 4381.7–4034.6 cm−1 and 6815.5–6471.6 cm−1 with the pretreatment of data using the first derivative and vector normalization of the near-infrared spectra, with the rank = 5, coefficient of determination = 0.8843, residual predictive deviation = 3.18, and root mean square error of prediction = 1.37. This work, therefore, provides an effective and convenient method for the rapid quantitative analysis of chlorogenic acid content in Eucommia leaf.