Hiramoto K, Li X, Makimoto M, Kato T, Kikugawa K
Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
Mutat Res. 1998 Nov 9;419(1-3):43-51. doi: 10.1016/s1383-5718(98)00123-5.
A component in instant coffee that caused DNA single strand breaks was isolated by successive ethyl acetate:ethanol extraction, silica gel column chromatography and high performance liquid chromatography using a reversed phase column. The active component was identified as hydroxyhydroquinone (HHQ). Incubation of supercoiled pBR 322 DNA with HHQ at 0.1 mM in phosphate buffer (pH 7.4) at 37 degreesC for 1 h caused single strand breaks, and reactive oxygen species, hydrogen peroxide and hydroxyl radical, were involved in DNA breaking by HHQ. Genotoxic effects of HHQ including DNA breaking activity through generation of reactive oxygen species have been well-demonstrated because the component is considered to be an important genotoxic intermediate metabolite of benzene. Occurrence of HHQ in coffee must have an important significance to consider genotoxicity of coffee.
乙醇萃取、硅胶柱色谱法以及使用反相柱的高效液相色谱法，从速溶咖啡中分离出一种导致DNA单链断裂的成分。该活性成分被鉴定为羟基对苯二酚（HHQ）。在37℃下于磷酸盐缓冲液（pH 7.4）中，将超螺旋pBR 322 DNA与0.1 mM的HHQ孵育1小时会导致单链断裂，并且活性氧、过氧化氢和羟基自由基参与了HHQ引起的DNA断裂。HHQ的遗传毒性作用，包括通过产生活性氧而产生的DNA断裂活性，已得到充分证实，因为该成分被认为是苯的一种重要的遗传毒性中间代谢产物。咖啡中HHQ的存在对于考虑咖啡的遗传毒性具有重要意义。
