Original Research Paper Acta Chromatographica DOI: 10.1556/AChrom.28.2016.1.5 0231–2522 © 2015 Akadémiai Kiadó, Budapest TLC-DPPH • Activity-Guided Separation and LC–DAD–MS Identification of Antioxidant Compounds from Mutellina purpurea L. Herb E. SIENIAWSKA 1, *, T. BAJ 1 , J. DUDKA 2 , T. MROCZEK 1 , AND K. GŁOWNIAK 1 1 Department of Pharmacognosy with Medicinal Plant Unit, Medical University of Lublin, 1 Chodzki Str, PL-20-093 Lublin, Poland 2 Medical Biology Unit, Medical University of Lublin, 8 Jaczewskiego Str, PL-20-090 Lublin, Poland *E-mail: esieniawska@pharmacognosy.org Summary. Many phytochemical investigations have been focused recently on the anti- oxidant activity of herbal extracts which can be used in phytotherapy. The previous study revealed antioxidative properties of Mutellina purpurea extract, but the constituents responsible for this action were not described yet. The aim of this study was activity- guided separation and identification of antioxidant compounds from M. purpurea herb. Thin-layer chromatography-2,2-diphenyl-1-picrylhydrazyl (TLC-DPPH • ) assay was used to detect compounds of interest; liquid chromatography–diode array detection–mass spectrometry (LC–DAD–MS) analysis allowed to identify antioxidants. The active frac- tions analyzed with LC–DAD–MS contained as a main compound chlorogenic acid ac- companied with p-coumaric acid, ferulic acid, three dicaffeoylquinic acids, and caffe- oylferuloylquinic acid. The fast TLC-DPPH • assay with LC–DAD–MS identification en- abled the accurate identification of antioxidants in M. purpurea herb, which was done for the first time. Key Words: antioxidant, Mutellina purpurea, polyphenolic compounds, DPPH, LC– DAD–MS analysis Introduction Among methods most commonly used for antioxidant activity evaluation, the DPPH • (2,2-diphenyl-1-picrylhydrazyl) assay is characterized by excel- lent reproducibility under certain conditions and does not require any spe- cial preparation. Thin-layer chromatography (TLC)-DPPH • assay is an ef- fect-directed analysis indicating the compounds responsible for antioxidant activity and, thus, can be used for antioxidant activity-guided separation and identification of active principles. The antioxidant power described in vitro with DPPH • as an effective concentration (EC 50 ) value ranged among Apiaceae plants from 242 to 1140 μg mL −1 [1–3]. Mutellina purpurea (Apiaceae) was used in traditional medicine for the substitution of calcium and potassium [4]. As secondary metabolites, it pro- duces coumarins, phenolic acids, flavonoids, and volatile compounds