DPPH radical-scavenging compounds from dou-chi, a soybean fermented food
Chen, Y.C. (Shizuoka Univ. (Japan)) | Sugiyama, Y. | Abe, N. | Kuruto Niwa, R. | Nozawa, R. | Hirota, A.
Dou-chi, a traditional soybean food fermented with Aspergillus sp., is usually used as a seasoning in Chinese food, and has also been used as a folk medicine in China and Taiwan. As 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavengers, four phenol compounds, one isoflavanone, eight isoflavones and one 4-pyrone have been isolated from dou-chi. Among these fourteen compounds, 3'-hydroxydaidzein, dihydrodaidzein and a 4-pyrone compound have not yet been isolated from soybean miso. The structure of the novel 4-pyrone compound, 3-((E)-2-carboxyethenyl)-5-(4-hydroxyphenyl)-4-pyrone-2-carboxyiic acid was elucidated by using the same compound as that obtained from the biotrans-formation of daidzein. 3'-Hydroxydaidzein showed as high DPPH radical-scavenging activity as that of alpha-tocopherol, and 6-hydroxydaidzein had mushroom tyrosinase inhibitory activity with an IC50 value of 10 microM. The order of estrogenic activity is as follows: genistein > daidzein >> 3'-hydroxydaidzein > 8-hydroxygenistein, using a green fluorescent protein expression system. Furthermore, the contents of isoflavones in the fermentation process of dou-chi were measured.
Показать больше [+] Меньше [-]