Quantitative determination of pinoresinol diglucoside in Eucommiae unloads by NIRS / 中国中药杂志

ABSTRACT

<p><b>OBJECTIVE</b>To establish a rapid determination method of pinoresinol diglucoside in Eucommiae unloads by near-infrared reflectance spectroscopy (NIRS).</p><p><b>METHOD</b>Forty-one samples of E. unloads were collected from three different producing areas and their main component, namely pinoresinol diglucoside, was determined by HPLC. Corresponding data of samples were collected from 12 000 to 4 000 cm(-1) by near-infrared reflectance spectroscopy. The spectral pretreatment was optimized by OPUS software and the calibration equations between the content of pinoresinol diglucoside and spectrum data were constructed by partial least squares regression.</p><p><b>RESULT</b>Available information could be extracted from spectra in the range from 7 502 to 4 597.6 cm(-1) after corrected by applying second derivative transformation and subtract a linear correction. Cross validation was used to prevent over-fitting. Good correlation existed between pinoresinol diglucoside content and NIR spectra ( R2 = 0.926 4, SEC = 0.029 and SEP = 0.066 2).</p><p><b>CONCLUSION</b>NIRS calibration equations developed in this study could be applied to the rapid analysis of the pinoresinol diglucoside content.</p>