Comparative Investigation Between Raw and Stir-Frying Processed Cuscutae Semen Based on HPLC Fingerprints Coupled With Chemometric Methods

The curative effect of Cuscutae Semen (CS) could be adjusted after stir-frying, and it is difficult to distinguish between the raw CS and stir-fried processed Cuscutae Semen (SFCS) in clinical practice. The paper aims to establish the fingerprints of raw and fried Cuscutae Semen products by high-performance liquid chromatography (HPLC) so that the compounds in raw and stir-fried products could be analyzed qualitatively and quantitatively. At the same time, the chemometrics method was used to evaluate the difference between CS and SFCS to provide reference for the research of traditional Chinese medicine (TCM) CS. The raw and SFCS products' related substances were separated on a C18 column (250 mm × 4.6 mm, 5 µm) maintained at 30 °C (column temperature). The mobile phase comprised 0.1% formic acid aqueous solution (A) and acetonitrile (B), and a detection wavelength of 328 nm. The data were imported into statistical software for chemometric analysis. The developed HPLC method exhibits good linearity and has good systematic applicability. The content of these 12 compounds in the samples was further determined and the data analyzed by chemometrics. The results showed that the composition of CS changed on heating, and HCA showed that CS and SFCS could be clearly distinguished. PCA showed that six components caused differences, namely neochlorogenic acid, cryptophyllogenic acid, caffeic acid, quercetin, isorhamnetin, and kaempferol. This study unequivocally establishes a chromatographic fingerprint method intended for the extensive analysis of raw and stir-fried processed CS, which could substantially enhance the quality control of CS and the rational development and utilization of TCM resources. This method for the simultaneous quantification of multiple compounds in CS and SFCS revealed the components responsible for the differences between raw and processed products. This will provide support for quality control of this herbal medicine.