While alpha-asarone (aA) and beta-asarone (bA) are genotoxic and were shown to be carcinogenic the mechanisms underlying these effects are not understood. Major metabolites of both compounds are epoxides which are mutagenic in the Ames test. We investigated their reactivity towards nucleosides and identified epoxide-derived DNA adducts with 2′-deoxyadenosine (dA) and 2′-deoxyguanosine (dG) using UPLC-UV/VIS, LC-MS/MS and NMR spectroscopy. The adducts were characterized as N⁶-1′-hydroxy-dihydro-asarone-dA and N²-1′-hydroxy-dihydro-asarone-dG. Chemical synthesis of these adducts, isotope labeled standards and development of a sensitive and specific isotope dilution mass spectrometric method allowed the quantification of DNA adducts formed in primary rat hepatocytes incubated with aA or bA over up to 48 h. We observed a concentration-dependent, nearly linear formation of DNA adducts, which was higher for bA than for aA. In time course experiments, the amount of DNA adducts reached a maximum within the first 6 h. Over the next 42 h, the amount of DNA adducts decreased, however DNA adducts were still detectable even at the lowest substrate concentration of 10 μM. These results clearly show that aA and bA are able to form epoxide-derived DNA adducts in mammalian cells which may be responsible for their genotoxic, mutagenic and carcinogenic mode of action.

尽管α-花生醚（aA）和β-花生醚（bA）具有遗传毒性，并被证明具有致癌性，但尚不清楚这些作用的潜在机制。两种化合物的主要代谢物都是环氧化物，在Ames试验中是致突变的。我们研究了它们对核苷的反应性，并使用UPLC-UV / VIS，LC-MS / MS和NMR光谱法鉴定了2'-脱氧腺苷（dA）和2'-脱氧鸟苷（dG）的环氧化物衍生的DNA加合物。加合物的特征为N ⁶ -1'-羟基-二氢-山葵-dA和N ²-1'-羟基-二氢-山葵素-dG。这些加合物的化学合成，同位素标记的标准品以及灵敏而特异性的同位素稀释质谱法的发展，可以定量在长达48小时内与aA或bA孵育的原代大鼠肝细胞中形成的DNA加合物。我们观察到了DNA加合物的浓度依赖性，近乎线性的形成，其中bA的浓度高于aA的浓度。在时程实验中，DNA加合物的数量在前6小时内达到最大值。在接下来的42小时内，DNA加合物的数量减少，但是即使在最低底物浓度为10μM的情况下仍可检测到DNA加合物。这些结果清楚地表明，aA和bA能够在哺乳动物细胞中形成环氧化物衍生的DNA加合物，这可能是它们的遗传毒性，诱变和致癌作用方式所致。