地黄炮制过程中生成一化合物，经鉴定为5－羟甲基糠醛，并用薄层层析－薄层扫描法测定了在炮制中其含量的动态变化，结果表明，地黄炮制成熟地黄后5－羟甲基糠醛含量增加20倍左右．

In the study on processing of Dihuang, a traditiollal Chinese drug composed of therhlzome of Rehmannia glutinose Libosch, attention was paid to reveal the chemioal changes occurred in the course or Processing. In order to find some clues ror the process control, changes in the TLC srecbrograms were examined and one of the component peak was found changing gradually as the processing went on.Phytochemical separation and identification revealed that the component peake features 5-hydroxy-methyl-furfurol (5-HMF ). TLCS specrometric estimation of the 5-HMF contents was developed and used to monitor the proeess.it was found That the 5-HMF content at the end of processing was 20 times higher than that he start.Biological assay indicated that 5-HMF possesses marked antiplatelet activity, which supports the use of Dihuang as a blood activating agent in traditonal Chinese medicine.