Contents lists available at ScienceDirect Phytochemistry Letters journal homepage: www.elsevier.com/locate/phytol GC-MS analysis of steroids and triterpenoids occurring in leaves and tubers of Tamus edulis Lowe Agata Rogowska a,1, ⁎ , Michał Styczyński b,1 , Cezary Pączkowski a , Anna Szakiel a , Miguel Ângelo A. Pinheiro de Carvalho c a Department of Plant Biochemistry, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096 Warszawa, Poland b Department of Bacterial Genetics, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096 Warszawa, Poland c ISOPlexis Germplasm Bank, University of Madeira, Funchal, Portugal ARTICLE INFO Keywords: Tamus edulis Dioscoreaceae GC–MS Steroids Steroid sapogenins Triterpenoids ABSTRACT Tamus edulis Lowe is an endemic perennial plant belonging to Dioscoreaceae family. The plant has long climbing stems, ovate leaves, fowers in spikes, feshy red berries and long tuberous roots. Young shoots and tuberous roots of T. edulis were used traditionally for nourishment and as a herbal medicine. Leaves and roots analyzed in the present study were collected in the northwest of Madeira island. The GC–MS analysis allowed to detect several steroids in free forms in diethyl ether extracts; and diosgenin with its isomer, yamogenin, in hydrolyzates from methanolic extracts.The obtained results reveal that Tamus edulis has some features common with other Dioscorea species, e.g., the presence of steroidal saponins with diosgenin and yamogenin as aglycones, or the phytosterol composition with predominating sitosterol. However, some other traits, like the relatively high content of free steroids (more than 1 mg/g d.w.) and their profle rich in cholesterol derivatives, can distinguish Tamus edulis from other Dioscorea species studied previously for their steroid and triterpenoid profle. 1. Introduction The Dioscoreaceae is a large plant family, that includes more than 600 species. Tamus edulis Lowe, a species belonging to this family, was described for the frst time by Lowe (1831) as a species occurring in Madeira. This perennial plant was sporadically cultivated in remote areas of this island and widely known by common name „norça” (Pinheiro de Carvalho et al., 2016). Tubers and young shoots of T. edulis were used traditionally for nourishment and as a herbal medicine. The plant has long climbing stems, ovate leaves (Fig. 1), fowers in spikes, feshy reddish berries when mature, and long brown tuberous roots with white-yellowish fesh. This species is considered as an endemic plant occurring naturally in Canary Islands and Madeira (Press and Short, 1994). Its endemicity is determined by its geographical and re- productive isolation. For a long time, Tamus has been considered as a monophyletic genus of fora of Madeira, holding T. edulis Lowe as a species with high genetic singularity (Press and Short, 1994; Borges et al., 2008). Tamus and Dioscorea genera were separated on the basis of fruit morphology: T. edulis forms a feshy berry while Dioscorea forms dry capsule, however, recent biochemical and genetic data shows their close relation (Wilkin et al., 2005). Based on the analysis of herbarium voucher material, but in the absence of other studies, T. edulis has been currently clasifed as one of numerous synonyms of Dioscorea communis (L.) Caddick and Wilkin (The Plant List, 2013). However, phylogenetic relationships between Dioscoreales used to be difcult to resolve (Chaïr et al., 2016). The confusion can be explained by high phenotypic variability of these species (Ferrer-Gallego and Boisset, 2016). Plants belonging to Dioscoreaceae family are interesting from pharmaceutical point of view due to saponin content. Saponins possess cytotoxic, cytostatic, anti-tumoral and chemo-preventive activity (Lacaille-Dubois and Wagner, 2000). They also positively afect anti- oxidative enzymes (Son et al., 2007). González et al. (1970) isolated several steroidal sapogenins from T. edulis leaves and twigs collected in Canary Islands. Besides diosgenin, tamusgenin, eduligenin and low- egenin, some others, more rare aglycons, i.e. 7-ketotamusgenin, 7-ke- todiosgenin, 25S-hydroxytamusgenin and afurigenin were also identi- fed (González et al., 1970, 1971). However, the whole profle of steroids and triterpenoids, particularly occurring in this plant in a free form, has not been investigated yet. Thus, the main aim of the present study was the qualitative and quantitative GC–MS analysis of non- https://doi.org/10.1016/j.phytol.2019.01.012 Received 15 October 2018; Received in revised form 27 December 2018; Accepted 10 January 2019 ⁎ Corresponding author. E-mail addresses: a.rogowska@biol.uw.edu.pl (A. Rogowska), mstyczynski@biol.uw.edu.pl (M. Styczyński), myhacp@biol.uw.edu.pl (C. Pączkowski), szakal@biol.uw.edu.pl (A. Szakiel), miguel.carvalho@staf.uma.pt (M.Â.A. Pinheiro de Carvalho). 1 These authors contributed equally to this paper. Phytochemistry Letters 30 (2019) 231–234 Available online 22 January 2019 1874-3900/ © 2019 Phytochemical Society of Europe. Published by Elsevier Ltd. All rights reserved. T