Schaller K, Höller H
Int J Vitam Nutr Res. 1976;46(2):143-8.
The effects upon thiamine absorption in-vitro and in-vivo by caffeic acid (a thiamine antagonist isolated from bracken) was studied, partly using 14C-thiamine. It was again shown that caffeic acid reduced the quantity of thiochrome positive thiamine, dependant upon the concentration ratio caffeic acid/thiamine. Caffeic acid was able to pass across the intestinal wall and to exert its antithiamine effect in the serosal incubation fluid. When caffeic acid was present in the mucosal fluid the amount of thiochrome positive thiamine passed to the serosal side was diminished according to the mucosal caffeic acid concentration. In-vitro studies with 14C-thiamine revealed, however, that thiamine modified and turned into a thiochrome negative form by caffeic acid was absorbed similarly to unaffected thiamine. Active transport in-vitro of thiamine was significantly inhibited by the presence of caffeic acid.
研究了咖啡酸（从蕨菜中分离出的一种硫胺素拮抗剂）对硫胺素体外和体内吸收的影响，部分实验使用了14C-硫胺素。再次表明，咖啡酸会降低硫色素阳性硫胺素的量，这取决于咖啡酸/硫胺素的浓度比。咖啡酸能够穿过肠壁，并在浆膜培养液中发挥其抗硫胺素作用。当黏膜液中存在咖啡酸时，传递到浆膜侧的硫色素阳性硫胺素的量会根据黏膜咖啡酸浓度而减少。然而，用14C-硫胺素进行的体外研究表明，被咖啡酸修饰并转化为硫色素阴性形式的硫胺素与未受影响的硫胺素吸收情况相似。咖啡酸的存在显著抑制了硫胺素的体外主动转运。
