Minor flavonolignans such as 2,3-dehydrosilybin, 2,3-dehydrosilychristin and 2,3-dehydrosilydianin, anhydrosilychristin, 2,3-dehydroanhydrosilychristin were isolated from Silybum marianum and/or synthesized (Pyszková 2016, Biedermann 2016, Biedermann 2019, Valentová 2019). Moreover, the importance of these compounds in silymarin has been summarized (Chambers 2017) and new HPLC method developed (Petrásková 2020).
We prepared enzymatically authentic standards of potential sulfated metabolites and validated the methods for their identification (Valentová 2017, Valentová 2018, Begines 2019). Purified (potential) metabolites were tested (see below) and are used for biological studies. The standards were also provided to the partners in the COST Action FA1403 POSITIVe in order to develop and validate methods determining their bioavailability (Koistinen 2019).