Dyestuff analyses were performed directly from the surface of different bluish and reddish colored historic textile samples by flowprobe™-electrospray ionization-high-resolution mass spectrometry (flowprobe™-ESI-HRMS). This real-time in situ microextraction method allowed rapid, reliable and minimal-destructive analysis without extra and time-consuming sample preparation and required only a minimum amount of valuable archaeological material. As demonstrated for indigo-type and anthraquinone dyes this technique is useful for the analysis of various types of textiles regardless of their fiber matrix, appearance or handicraft and is also suitable for investigating fragile archeological fibers. Thus, flowprobe™-ESI-HRMS is a promising analytical tool for characterizing organic colorants in objects of archaeological interest.
Organic dyes of animal and plant origin have often been used by our ancestors to create textiles with polychromic ornamental patterns, and dyestuff analyses reveal how ancient cultures used these natural colorants. Mass spectrometry can characterize ancient colorants from these textiles, but its combination with separation techniques such as liquid chromatography requires the destruction of the pattern to extract organic dyes from the fabrics. In this study we applied mass spectrometry imaging (MS imaging) on colorful patterned textiles to show the spatial distribution of indigo-type and anthraquinone-type dyes. We evaluated different sample preparation techniques for matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF)-MS imaging, e.g. the production of imprints in TLC (thin layer chromatography) aluminum sheets and the embedding of the material in Technovit7100 to produce thin sections. Our protocol enabled the detection of indigo-type dyes directly on a historic textile of more than 2,000 years old embedded in Technovit7100. This is the first-time application of MALDI-TOF-MS imaging to map different organic dyestuffs on archeological remains.
In this study, we explore the cytotoxic activity of four natural abenquines (2a-d) and fourteen synthetic analogues (2e-j and 3a-h) against a panel of six human cancer cell lines using a SRB assay. It was found that most of the compounds revealed higher levels of cytotoxic activities than naturally occurring abenquines. The analogues carrying ethylpyrrolidinyl and ethylpyrimidinyl with either an acetyl group (2h-i) or a benzoyl group (3f-g), were the most potent against all human cancer cell lines and displayed EC between a range of 0.6-3.4μM. Notably, of the compounds tested, compound 2i proved the most cytotoxic against both ovarian (A2780) and breast (MCF7) cells, showing EC=0.6 and 0.8μM respectively. Likewise, the analogues 2i, 3f and 3g showed strong activity against cell HT29 with EC=0.9μM for these compounds.
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