HPLC chromatogram changes with processing for roots of Radix Rehmanniae / 中草药

ABSTRACT

Object To investigate the saccharide changes of Radix Rehmanniae when being processed. Methods The fresh roots were torrefied at 65 ℃ and sampled at 0,1, and 6 d. The samples and 4 h steamed slices of those dried roots were extracted with hot water respectively. The extracts were subjected to HPLC analysis, Sugar pak 1 column at 80 ℃,with water as the mobile phase at 0 7 mL/min and detected by RID. Results There are three principal components in the fresh roots, i.e. stachyose (11%-15%), sucrose (0 30%-0 92%), and catalpol (0 27%-0 88%). In the processing of the fresh roots, the HPLC chromatorams of the extracts differed to each other remarkbly. On the chromatogram of roots torrefied for 1 d, one distinct monosaccharide peak displayed at 10 2 min, which is likely to be galactose, and it become prominent in the dried roots together with raffinose. In steamed ones, the peaks of fructose and glucose became outstanding. Conclusion According to the HPLC chromatograms, the degalacto sylation of stachyose may take place during torrifying, while defructosylation during steaming. One of the principal purposes of the processing may be for stachyose degradation for its flatulence causing character.