Identification of yellow dye plant chemical markers for applications in cultural heritage using LC-MS-based metabolomics and molecular networking

Before the advent of synthetic dyes in the mid-19th century, dye plants were one of the main resources for coloring textiles. The analysis of specific molecules present in cultural heritage objects can help to determine the plants used to dye them and thus to better understand the context in which they have been manufactured. However, finding the botanical origin of the yellow color can be challenging. Indeed, there is a wide diversity of yellow dye plants in nature and some natural yellow compounds are present in several species, which complicates the identification of the producing organism. Surprisingly, metabolomics, a powerful analytical approach for comparing large sets of molecules in complex samples and detecting specific chemical markers, has so far only rarely been used for cultural heritage purposes. In this context, an LC-MS-based metabolomics approach was developed using a panel of fourteen common yellow dye plant species. Statistical analyses then revealed chemical markers for each of them and the molecules of interest were tentatively annotated using several approaches, including molecular networking.