Abou-Hany Rahma A G, Urraca Javier L, Descalzo Ana B, Gómez-Arribas Lidia N, Moreno-Bondi María C, Orellana Guillermo
Chemical Optosensors and Applied Photochemistry Group (GSOLFA), Department of Organic Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28040 Madrid, Spain.
Chemical Optosensors and Applied Photochemistry Group (GSOLFA), Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28040 Madrid, Spain; CEI Campus Moncloa, UCM-UPM, Avda. Complutense s/n, 28040 Madrid, Spain.
J Chromatogr A. 2015 Dec 18;1425:231-9. doi: 10.1016/j.chroma.2015.11.055. Epub 2015 Nov 28.
Molecularly imprinted porous polymer microspheres have been prepared for selective binding of alternariol (AOH), a phenolic mycotoxin produced by Alternaria fungi. In order to lead the synthesis of recognition materials, four original AOH surrogates have been designed, prepared and characterized. They bear different number of phenol groups in various positions and different degree of O-methylation on the dibenzo[b,d]pyran-6-one skeleton. A comprehensive library of mixtures of basic, acidic or neutral monomers, with divinylbenzene or ethyleneglycol dimethacrylate as cross-linkers, were polymerized at a small scale in the presence of the four molecular mimics of the toxin molecule. This polymer screening has allowed selection of the optimal composition of the microbeads (N-(2-aminoethyl)methacrylamide, EAMA, and ethylene glycol dimethacrylate). The latter are able to bind AOH in water-acetonitrile (80:20, v/v) with an affinity constant of 109±10mM(-1) and a total number of binding sites of 35±2μmolg(-1), being alternariol monomethylether the only competitor species. Moreover, (1)H NMR titrations have unveiled a 1:2 surrogate-to-EAMA stoichiometry, the exact interaction sites and a binding constant of 1.5×10(4)M(-2). A molecularly imprinted solid phase extraction (MISPE) method has been optimized for selective isolation of the mycotoxin from aqueous samples upon a discriminating wash with 3mL of acetonitrile/water (20:80, v/v) followed by determination by HPLC with fluorescence detection. The method has been applied, in combination to ultrasound-assisted extraction, to the analysis of AOH in tomato samples fortified with the mycotoxin at five concentration levels (33-110μgkg(-1)), with recoveries in the range of 81-103% (RSD n=6). To the best of our knowledge, this is the first imprinted material capable of molecularly recognizing this widespread food contaminant.
已制备出分子印迹多孔聚合物微球，用于选择性结合链格孢酚（AOH），这是一种由链格孢属真菌产生的酚类霉菌毒素。为了指导识别材料的合成，设计、制备并表征了四种原始的AOH替代物。它们在二苯并[b,d]吡喃-6-酮骨架上的不同位置具有不同数量的酚基以及不同程度的O-甲基化。以二乙烯基苯或乙二醇二甲基丙烯酸酯作为交联剂，在四种毒素分子的分子模拟物存在下，小规模聚合了由碱性、酸性或中性单体组成的综合混合物库。这种聚合物筛选使得能够选择微珠的最佳组成（N-(2-氨基乙基)甲基丙烯酰胺，EAMA，和乙二醇二甲基丙烯酸酯）。后者能够在水-乙腈（80:20，v/v）中结合AOH，亲和常数为109±10 mM⁻¹，结合位点总数为35±2 μmol g⁻¹，链格孢酚单甲醚是唯一的竞争物种。此外，¹H NMR滴定揭示了替代物与EAMA的化学计量比为1:2、确切的相互作用位点以及结合常数为1.5×10⁴ M⁻²。已优化了一种分子印迹固相萃取（MISPE）方法，用于从水性样品中选择性分离霉菌毒素，先用3 mL乙腈/水（20:80，v/v）进行区分洗涤，然后通过高效液相色谱-荧光检测进行测定。该方法已与超声辅助萃取相结合，应用于分析添加了五种浓度水平（33 - 110 μg kg⁻¹）霉菌毒素的番茄样品中的AOH，回收率在81 - 103%范围内（RSD n = 6）。据我们所知，这是第一种能够分子识别这种广泛存在的食品污染物的印迹材料。
