Metabolomics quantitative data of three foxglove species (genus Digitalis, fam. Plantaginaceae) from Central Balkan Peninsula Subject: Leaves from the flowering stems of three Digitalis species (Digitalis grandiflora, D. lanata, and D. ferruginea), originating from 28 populations from the Central Balkan Peninsula, were subjected to targeted metabolomics. Totally 16 compounds from the groups of phenolics (phenolic acids and flavonoids) and cardenolides were quantified in analyzed samples, and values are presented as mg/L of extract. Material and methods: After harvesting, leaves were immediately transferred into plastic zip-bags containing silica gel. Prior to methanol extraction, leaves were ground to a fine powder using liquid nitrogen. Approximately 50 mg of dry plant material was extracted with 1 ml of 80% methanol overnight at room temperature. The next day, samples were sonicated for 1 h and centrifuged at 10,000g for 10 min. The supernatants were filtered through 0.2-mm cellulose filters and stored at 4°C until use. Analysis: High Pressure Liquid chromatography (HPLC) coupled with Mass Spectrometry (MS) was used for the quantification of 16 targeted compounds from the groups of phenolic acids, derivatives of either hydroxycinnamic (5-O-caffeoylquinic acid, caffeic acid, p-coumaric acid, and aesculetin) or hydroxybenzoic acid (p-hydroxybenzoic acid, syringic acid, and protocatechuic acid), flavonoids belonging to flavones (luteolin, hispidulin, isoorientin), flavonols (quercetin-3-O-glucoside, isorhamnetin), and flavanones (naringin), as well as cardenolides (digoxin, lanatoside C, and deslanoside (syn. desacetyllanatoside C)). Quantification was performed adopting the external standard method, based on the calibration curves of pure compounds. Sample type: Methanol extracts of leaves from flowering stems of Digitalis grandiflora, D. lanata, and D. ferruginea. Platform: UHPLC/DAD/(-)HESI-MS2 instrument (High Pressure Liquid Chromatograph with Diode Array Detector and configured with Quantum Access Max Tripple Quadrupol, Thermo Scientific). Instrument control: XcaliburTM software (ver. 2.2, Thermo Scientific); Chromeleon™ Chromatography Data System (CDS) Software (Thermo Scientific). Data acquisition: Xcalibur software (ver. 2.2, Thermo Scientific). The selected reaction monitoring (SRM) mode of the instrument was used for the quantification of the targeted compounds in the samples. Data processing: Xcalibur software (ver. 2.2), Thermo Scientific Data analysis: Quantification was performed using the Quan Browser function of the Xcalibur software (ver. 2.2, Thermo Scientific). The compounds were quantified based on the calibration curves of commercial standards. Calibration curves revealed good linearity, with r2 values exceeding 0.99 (peak areas vs. concentration). The total amount of each compound was evaluated by calculation of the peak area and is expressed as mg/kg. The concentration of digoxin is expressed via the calibration curve of deslanoside. Statistics: Raw data are presented, not subjected to the statistical analyses. Data presentation: Presented data are raw data of 16 quantified compounds in totally 28 populations of 3 Digitalis species, and are presented as mg/kg DW (dry weight). Quantitative data are presented in 3 separate *.csv files, which are named according to the Latin names of analyzed Digitalis species: DG.csv, DL.csv, DF.csv. Rows are labeled with the species abbreviation (DA, DL, and DF) and further with the population accession codes (G1-10, M1-7, SR1-10, B1-10, MRU1-10, DABB1-10, DABZ1-10, DAJE1-10, DACC1-10, DAOS1-10, DADB1-10, DAHC1-10, DADZ1-7, DAZ1-7, DABARE1-8, LV1-8, KMB1-10, DLBAL1-10, DLS1-7, DLZAV1-10, DLJE1-7, DFDL1-10, DFDL21-10, DFDB1-8, DFZAO1-10, DFSN1-10, DFPR1-9, DFBK1-10), while columns are labeled with abbreviations of the quantified compounds (5OCA, CA, pCoA, AE, pHBA, SA, PA, LU, HI, IO, QU, IR, NA, DX, LC, DS). Highlight: High diversification between analyzed taxa was observed based on the quantitative data for 16 targeted compounds, as well as low intra-population variability. Abbreviations: DA = Digitalis grandiflora DL = Digitalis lanata DF = Digitalis ferruginea G1 = Serbia: Homolje Mt., Gornjak M = Serbia: Homolje Mt., Milanovac SR = Serbia: Pomoravlje, Senje B = Serbia: Djerdap National Park, Brnjica MRU = Serbia: Majdanpek, Majdanpek mine DABB = Serbia: Nature Park Stara planina, Balta Berilovac DABZ = Serbia: Nature Park Stara planina, Babin Zub DAJE = Serbia: Landscape of Outstanding Qualities "Vlasina", Jerma DACC = Serbia: National Park Fruska gora, Crni Cot DAOS = Serbia: National Park Fruska gora, Orlova stena DADB = Serbia: Jablanik Mt., Debelo brdo 1 DAHC = Serbia: National Park Tara, Hajducka cesma DADZ = Serbia: Zlatar Mt., Drmanovici DAZ = Bosnia and Hercegovina: Sutjeska National Park, Mostanica DABARE = Bosnia and Hercegovina: Sutjeska National Park, Donje Bare Lake LV = Serbia: Djerdap National Park, Lepenski Vir KMB = Serbia: Djerdap National Park, Kapetan Misin breg DLBAL = Serbia: Rtanj Mt., Mirovo DLS = Serbia: Knjazevac, Skrobnica DLZAV = Serbia: Nature Park Stara planina, Zavojsko jezero DLJE = Serbia: Landscape of Outstanding Qualities "Vlasina", Jerma DFDL = Serbia: Majdanpecka Domena, Debeli lug 1 DFDL2 = Serbia: Majdanpecka Domena, Debeli lug 2 DFDB = Serbia: Jablanik Mt., Debelo brdo 1 DFZAO = Serbia: National Park Tara, Zaovine Lake DFSN = Serbia: Zlatibor Mt., Senista DFPR = Bosnia and Hercegovina: Republika Srpska, Prijedjel DFBK = Serbia: Radan Mt., Beli Kamen 5OCA = 5-O-Caffeoylquinic acid CA = Caffeic acid pCoA = p-Coumaric acid AE = Aesculetin pHBA = p-Hydroxybenzoic acid SA = Syringic acid PA = Protocatechuic acid LU = Luteolin HI = Hispidulin IO = Isoorientin QG = Quercetin-3-O-glucoside IR = Isorhamnetin NA = Naringin DX = Digoxin LC = Lanatoside C DS = Deslanoside (syn. desacetyllanatoside C))