Mistletoe chronobiology: 27 years of daily metabolomic fingerprinting (dataset 1)

<p>Chronobiological aspects of mistletoe&nbsp;have been studied for decades&nbsp;<span>(Fyfe, 1969, Scheer et al., 1992, Fl&uuml;ckiger and Baumgartner, 2002, Dorka et al., 2007, Urech et al., 2009, Derbidge et al., 2013, Derbidge et al., 2016)</span>.<span> One of the pioneers of such studies was Agnes Fyfe, a researcher at Hiscia Research Institute (Society for Cancer Research, Arlesheim, Switzerland). Already in the 1950s, with the aim of identifying optimal harvesting times, she started to build up a dataset of chromatograms using a form of metabolomic fingerprinting based on pattern formation peculiar in terms of ease, rapidity and affordability. She conducted daily chromatograms of&nbsp;<em><span>Viscum album </span></em>ssp. <em><span>album</span></em> L. for nearly 30 years (from November 1958 to October 1985) creating a unique heritage.</span></p> <p><span>In 2020, half of it, namely the &ldquo;Gold Fyfe dataset&rdquo;, was digitized. A total of 27 979 chromatograms showing recurring variations of different patterns compose the Gold Fyfe dataset. </span><span>Part of the chromatograms were made with 50% mistletoe extract concentration (n= 19 109; here referred to as "dataset 1").&nbsp;</span></p> <p><span>The following information was always recorded on each chromatography paper: sample name and concentration, harvest date and a numerical identification code. Additional information can be reported concerning the sample, as extract rising time, humidity and temperature. But also reagent information such as name and concentration, reagent rising time, humidity and temperature. Moreover, additional handwritten notes can appear on the right upper corner of the chromatographic paper.</span></p> <p><span>Chromatograms were scanned in reflective mode using an Epson Perfection V600 scanner (Epson, Kloten, Switzerland). Since the chromatograms are colour pictures,<span>&nbsp; </span>colours were calibrated using: IT 8.7/2 RF target (Wolf Faust, Frankfurt, Germany) and SilverFast Ai Studio 8.8 (LaserSoft Imaging AG, Kiel, Germany) as calibration program. Images were saved in TIFF format, 300 DPI, RGB, 16 cm x 17 cm.</span></p> <p>Each TIFF file was named in the following way YYYYMMDD_50_dx. In particular:</p> <ul> <li>YYYYMMDD: refers to sample harvest date.</li> <li>50: refers to sample extract concentration (50%).</li> <li>dx: refers to duplicate number (from 1 up to 8). &nbsp;Chromatograms are considered duplicates if the harvesting date and hour is the same. The standard harvest time is 8 am and it may/not be specified on the chromatograms. Harvesting time is specified in the TIFF file name only if it is different than the standard (8 am). In that case, the name of the TIFF file is: YYYYMMDD_50/10_HHHH_dx (where HHHH stands for harvesting time).</li> </ul> <p>&nbsp;</p>