OBJECTIVETo analysis the changes of two chemical constituents, namely 2, 3-dihydro-3, 5- dihydroxy-6-methyl-4H-pyran-4-one (DDMP) and 5-hydryoxymethyl-furfural (5-HMF) produced in Radix Polygoni Multiflori after processing, with processing time, and to determine the contents of 5-HMF in samples of Radix Polygoni Multiflori and Radix Polygoni Multiflori preparata.

METHODAn HPLC method was applied with a Zobax SB-C18 (3.9 mm x 150 mm, 5 microm) column by a elution using methanol-water (10: 90) as the mobile phase. The detection was set at UV 280 nm.

RESULTThe contents of DDMP were increasing with the processing time until 24 hour, followed by a decrease until 60 hour process. The contents of 5-HMF were increasing gradually throughout the 60 hour steaming process. The contents of 5-HMF in 11 samples of Radix Polygoni Multiflori preparata were from 0.013% to 0.101%, and only one in 4 samples of Radix Polygoni Multiflori containing trace amount of 5-HMF.

CONCLUSIONThe chemical components in Radix Polygoni Multiflori were changed during the processing procedures. Therefore, the processing of Radix Polygoni Multiflori should be controlled and standardized.