Hindsø Landin H, Tareke E, Rydberg P, Olsson U, Törnqvist M
Dept of Molecular Genome Research, Stockholm University, SE 10691, Stockholm, Sweden.
Food Chem Toxicol. 2000 Nov;38(11):963-9. doi: 10.1016/s0278-6915(00)00093-4.
Studies of adducts from reactive compounds to haemoglobin (Hb) by gas chromatography-tandem mass spectrometry according to the N-alkyl Edman method reveals the occurrence of N-(2,3-dihydroxypropyl)valine (diHOPrVal) at levels of 1-2 pmol/g Hb, in persons without known exposure. The hypothesis that this background originates from glycidol or related compounds during heating of food was tested in experiments with rats. Animals fed fried animal feed for 30 or 72 days showed an increase of the diHOPrVal level by about 50% compared with controls. Several arguments, such as the formation of reactive oxiranes by heat-induced dehydration of glycol configurations in glycerol and sugars, support the idea that glycidol (or e.g. glycidyl esters) are precursors of the adduct. In Hb samples, reduced for stabilisation of aldehyde adducts, relatively high levels of adducts determined as diHOPrVal were found, although without significant relation to frying of the feed. There is thus no indication that reduction in vivo of, for example, the Schiff base from glyceraldehyde, is a pathway for formation of the diHOPrVal. The background level of diHOPrVal in humans Hb is low, and the cancer risk associated with exposure to the specific alkylator-probably glycidol-formed in cooking, is therefore presumably low. The result implies, however, that low-molecular mass mutagenic oxiranes formed during the heating of food should be studied further.
采用气相色谱 - 串联质谱法，根据N - 烷基埃德曼法对反应性化合物与血红蛋白（Hb）形成的加合物进行研究，结果显示，在无已知暴露史的人群中，N -（2,3 - 二羟丙基）缬氨酸（diHOPrVal）的含量为1 - 2 pmol/g Hb。关于这种背景加合物源于食物加热过程中缩水甘油或相关化合物的假说，在大鼠实验中得到了验证。与对照组相比，喂食油炸动物饲料30天或72天的动物，其diHOPrVal水平升高了约50%。诸如甘油和糖类中的二醇构型经热诱导脱水形成反应性环氧乙烷等多项论据，支持了缩水甘油（或如缩水甘油酯）是该加合物前体的观点。在用于稳定醛加合物而进行还原处理的Hb样本中，发现以diHOPrVal测定的加合物水平相对较高，尽管与饲料油炸并无显著关联。因此，没有迹象表明例如甘油醛席夫碱在体内的还原是形成diHOPrVal的途径。人体Hb中diHOPrVal的背景水平较低，因此，与烹饪过程中形成的特定烷基化剂（可能是缩水甘油）暴露相关的癌症风险可能较低。然而，这一结果意味着，食物加热过程中形成的低分子量诱变环氧乙烷值得进一步研究。
