Mapari Sameer A S, Hansen Michael E, Meyer Anne S, Thrane Ulf
Department of Systems Biology, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
J Agric Food Chem. 2008 Nov 12;56(21):9981-9. doi: 10.1021/jf801817q. Epub 2008 Oct 9.
Monascus pigments have been used as natural food colorants in Asia for centuries. They are not authorized for use in the European Union and the United States mainly due to the risk of coproduction of the mycotoxin citrinin by Monascus spp. In the present study, we screened for novel producers of Monascus-like pigments from ascomycetous filamentous fungi belonging to Penicillium subgenus Biverticillium that are not reported to produce citrinin or any other known mycotoxins. The screening was carried out using the X-hitting algorithm as a tool to quickly screen through chromatographic sample data files of 22 different Penicillium extracts with 12 Monascus pigment extracts as controls. The algorithm searched for the most similar UV-vis spectra of the metabolites (cross hits) present in the pigment extracts to those of the selected reference metabolites viz. monascin, rubropunctatin, rubropunctamine, and citrinin. The cross hits were then manually identified on the basis of their UV-vis and mass spectra. X-hitting was found to be a good tool in the rapid screening of crude pigment extracts. Monascus pigments were discovered in the extracts of two closely related species of Penicillium that were only distantly related to the genus Monascus. Monascorubrin, xanthomonasin A, and threonine derivatives of rubropunctatin were identified in the extract of Penicillium aculeatum IBT 14263, and monascorubrin was identified in the extract of Penicillium pinophilum IBT 13104. None of the tested Penicillium extracts showed the presence of citrinin. Thus, the present study brought out two novel promising sources of yellow, orange, and purple-red Monascus-like food pigments in the species of Penicillia that do not produce citrinin and opened the door to look for several more new promising sources of natural food colorants in the species of Penicillia.
红曲色素在亚洲作为天然食用色素已使用了几个世纪。它们在欧盟和美国未被批准使用，主要是由于红曲霉菌株有共同产生霉菌毒素桔霉素的风险。在本研究中，我们从青霉属双轮青霉亚属的子囊丝状真菌中筛选新型红曲样色素的产生菌，这些真菌未被报道产生桔霉素或任何其他已知霉菌毒素。筛选使用X-hitting算法作为工具，快速筛选22种不同青霉提取物的色谱样品数据文件，并以12种红曲色素提取物作为对照。该算法在色素提取物中搜索代谢物（交叉命中）与所选参考代谢物（即红曲素、红斑红曲素、红曲胺和桔霉素）最相似的紫外-可见光谱。然后根据其紫外-可见光谱和质谱对交叉命中物进行人工鉴定。发现X-hitting是快速筛选粗色素提取物的良好工具。在与红曲属关系较远的两种密切相关的青霉提取物中发现了红曲色素。在针刺青霉IBT 14263的提取物中鉴定出红曲红素、黄红红曲素A和红斑红曲素的苏氨酸衍生物，在嗜松青霉IBT 13104的提取物中鉴定出红曲红素。所测试的青霉提取物均未显示桔霉素的存在。因此，本研究在不产生桔霉素的青霉物种中发现了两种新的有前景的黄色、橙色和紫红色红曲样食用色素来源，并为在青霉物种中寻找更多新的有前景的天然食用色素来源打开了大门。
