Identification and in vitro cytotoxicity of ochratoxin a degradation products formed during coffee roasting
Identification and in vitro cytotoxicity of ochratoxin a degradation products formed during coffee roasting
复制标题
DOI：
10.1021/jf801296z
复制
发表时间：
2008-07-23
影响因子：
6.1
通讯作者：
Humpf, Hans-Ulrich
中科院分区：
文献类型：
--
作者：
Cramer, Benedikt;Koenigs, Maika;Humpf, Hans-Ulrich
在咖啡烘焙过程中，真菌毒素赭曲霉毒素A的降解率高达90%。为了研究赭曲霉毒素A的降解过程，进行了模型加热实验，并用HPI-C-DAID和HPLC-MS/MS对反应产物进行了分析。鉴定了两种赭曲霉毒素A的降解产物，确定了它们的结构和绝对构型。作为降解反应，鉴定了14-(R)-赭曲霉毒素A的异构化反应和14-脱羧-赭曲霉毒素A的脱羧反应。随后，开发了一种测定烘焙咖啡中这些化合物的分析方法。采用HPLC-MS/MS和稳定同位素稀释法进行定量分析。用这种方法对德国市场上的15个咖啡样品进行了分析，结果表明，在咖啡烘焙过程中，赭曲霉毒素A非对映体14-(R)-赭曲霉毒素A的形成量高达赭曲霉毒素A的25.6%，脱羧产物仅形成微量。为了进行毒性评估，首先用这两种新物质进行了初步的细胞培养试验。两种降解产物在体外培养的人肾上皮细胞中均表现出较高的IC50值，并在较高浓度下引起细胞凋亡。因此，这些细胞培养数据表明，降解产物的细胞毒性低于赭曲霉毒素A。
The mycotoxin ochratoxin A is degraded by up to 90% during coffee roasting. In order to investigate this degradation, model heating experiments with ochratoxin A were carried out, and the reaction products were analyzed by HPI-C-DAID and HPLC-MS/MS. Two ochratoxin A degradation products were identified, and their structure and absolute configuration were determined. As degradation reactions, the isomerization to 14-(R)-ochratoxin A and the decarboxylation to 14-decarboxy-ochratoxin A were identified. Subsequently, an analytical method for the determination of these compounds in roasted coffee was developed. Quantification was carried out by HPLC-MS/MS and the use of stable isotope dilution analysis. By using this method for the analysis of 15 coffee samples from the German market, it could be shown that, during coffee roasting, the ochratoxin A diastereomer 14-(R)-ochratoxin A was formed in amounts of up to 25.6% relative to ochratoxin A. The decarboxylation product was formed only in traces. For toxicity evaluations, first preliminary cell culture assays were performed with the two new substances. Both degradation products exhibited higher IC50 values and caused apoptotic effects with higher concentrations than ochratoxin A in cultured human kidney epithelial cells. Thus, these cell culture data suggest that the degradation products are less cytotoxic than ochratoxin A.