In recent years, research in pharmacology has made remarkable progress. However, there are still many things that we do not know about both Kampo medicines and their fragrances such as mechanisms of action, etc., even though they have existed since ancient times. Were they not studied because they were unproductive subjects for research, or were they not the subject of research because they were difficult to elucidate? In this review article, I would like to summarize the background of Kampo medicines and their fragrances, and hope to provide suggestions for future clarification of the effects of the fragrances in Kampo medicines.

Traditional Chinese medicine (TCM) places an emphasis on the human and nature relationship, it also believes that the balance of Yin and Yang which are the key aspect of the human body is fundamental to maintaining our health. TCM values individuals when treatment and preventative methods are concerned. Many commonly used Chinese herbal medicines in the TCM formulae have unique fragrances, these aromatic characters are used as part of the treatment based on the TCM theory.

Agarwood has been valued since ancient times as a noble, high-grade fragrant wood. Because of its rarity, agarwood is traded at a high price, and the number of its original plants has been drastically reduced due to a succession of overharvesting. However, an efficient agarwood cultivation method has not yet been developed. The fragrance of agarwood is mainly derived from 2-(2-phenylethyl)chromones (PECs). Recently, we identified a key enzyme that forms the PEC skeleton. This paper outlines the characteristics of the enzyme, and the biosynthetic pathway of PECs.

Some crude drugs have characteristic odor. Their fragrance constituents are defined as characteristic markers for crude drug quality control and should be quantified. Quantitative assays are commonly performed using chromatography systems ; however, they require analytical standards corresponding to the characteristic markers for generating accurate calibration curves. Nevertheless, it is impossible to accurately determine the contents of naturally occurring compounds, such as flavor components, in crude drugs without analytical standards whose purities have been precisely certified. This study introduces a quantitative method based on relative molar sensitivity, which was recently reported as a new solution to this problem.