Contents of eight saccharides in unprocessed and processed Rehmannia glutinosa and content changes at different processing time points / 中草药

ABSTRACT

Objective: To analyze the contents of eight saccharides in unprocessed and processed Rehmannia glutinosa by HPLC and to investigate the impacts of processing time on saccharides in R. glutinosa. Methods: HPLC conditions were as follows Prevail Carbohydrate ES column (250 mm × 4.6 mm, 5 μm), flow rate of 0.8 mL/min, ELSD detector, acetonitrile as mobile A and water as mobile B for gradient elution. Results: Fructose, glucose, surcrose, melibiose, raffinose, manninotriose, stachyose, and verbascose were separated with good linear relationships within their corresponding concentration ranges, the r values were within 0.998 4-0.999 7; the average recovery was 97.5%-103.2%. The content analysis at different processing time points showed that surcrose, raffinose, stachyose, and verbascose exhibited decreasing trend during processing, while fructose, glucose, melibiose, and manninotriose exhibited significantly increasing trend. Conclusion: The proportions of saccharides in unprocessed and processed R. glutinosa are significantly different, and the results of this study could provide the data support for revealing the processing mechanism of R. glutinosa.