Antitrypanosomal Activity of a Novel Taccalonolide from the Tubers of Tacca leontopetaloides Vivian T. Dike, a Burbwa Vihiior, a Joel A. Bosha, b Tung Mei Yin, c Godwin Unekwuojo Ebiloma, d Harry P. de Koning, d John O. Igoli a * and Alexander I. Gray c ABSTRACT: Introduction – Several taccalonolides with various bioactivities have been isolated from Tacca species but no studies to isolate taccalonolides with anti-trypanosomal activity from Tacca leontopetaloides have been reported. Objectives – To analyse extracts of the roots of Tacca leontopetaloides, purify the extracts by column chromatography and iden- tify isolated compounds by spectroscopic methods. The compounds and fractions will be tested for antitrypanosomal activity in vitro against Trypanosoma brucei brucei. Material and methods – Dried roots or tubers of Tacca leontopetaloides, chromatographic separation and spectroscopic identification. Results – A novel taccalonolide A propanoate and some known taccalonolides were isolated and their structures were determined by NMR and mass spectrometry Conclusion – Several taccalonolides were isolated from Tacca leontopetaloides and were found to have in vitro antitrypanosomal activity against Trypanosoma brucei brucei and EC 50 values for the isolated compounds were from 0.79 μg/mL. Copyright © 2016 John Wiley & Sons, Ltd. Keywords: Taccalonolides; Tacca leontopetaloides; antitrypanosomal activity; taccalonolide A 12-propanoate Introduction Tacca leontopetaloides commonly known as Bat flower or Polyne- sian arrowroot is a wild perennial herb of the family Taccaceae. It is naturally distributed from West Africa through southeast Asia to northern Australia (Ukpabi et al., 2009). There are about 15 Tacca species worldwide. Through the ages, various parts of the plants were used in traditional medicine for treatment of gastric ulcers, tooth ache, stomach ache, high blood pressure, hepatitis, enteritis and sexual dysfunction (Peng et al., 2011). In northern Nigeria, the tubers are processed for food. The root is mashed and put topically on guinea worm infected area of the body, and is also taken as an infusion to treat hepatitis (Kay, 1987). In Plateau state of Nigeria for instance, the root preparation is used for treating snake bite and some infections (Borokini and Ayodele, 2012). Additionally, the tubers are used to treat stomach disorders, mainly diarrhoea and dysentery (Ukpabi et al., 2009). Over 134 compounds with different bioactivities have been isolated from Tacca species comprising of steroids, terpenoids, diaryheptanoids and taccalonolides (Chen et al., 1987, 1988a, 1988b; Yokosuka et al., 2002; Mühlbauer et al., 2003; Jiang et al., 2014; Ni et al., 2015). The first taccalonolide was isolated over five decades ago from the tubers of Tacca leontopetaloides when the “bitter principle” of the plant characterised as taccalin was being examined (Chen et al ., 1987). The discovery of the cytotoxic and microtubule stabilising activ- ity of taccalonolides (Peng et al., 2011; Li et al., 2012), has generated interest in this class of compounds. This activity was found to be without tubulin assembly and binding to the microtubules unlike Paclitaxel (Buey et al., 2005). Taccalonolide A (1) (Risinger and Mooberry, 2010) is claimed to be important for initiation of Paclitaxel-like microtubule bundling and thus it is regarded as the first microtubule stabilising agent isolated from a plant since identification of the mechanism of action of Paclitaxel (Tinley et al., 2003). However, more recent Taccalonolides (AJ and AF) show a different binding mode which is still unknown (Li et al., 2011). They are therefore, said to have the potential of becoming anti-cancer drugs (Tinley et al., 2003). This report describes the iso- lation and structure elucidation of a novel taccalonolide from the tubers of Tacca leontopetaloides. The in vitro anti-trypnosomal activity of the isolated taccalonolides and other taccalonolide con- taining fractions against Trypansonsoma brucei brucei was also evaluated. This is the first report of antitrypanosomal activity for this class of compounds, and based on the results, these * Correspondence to: John O. Igoli, Phytochemistry Research Group, Department of Chemistry, University of Agriculture PMB 2373, Makurdi, Benue State, Nigeria E-mail: igolij@gmail.com a Phytochemistry Research Group, Department of Chemistry, University of Agriculture PMB 2373, Makurdi, Benue State, Nigeria b Department of Veterinary Physiology, Pharmacology and Biochemistry, University of Agriculture, PMB 2373 Makurdi, Benue State, Nigeria c Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow, G4 0NR, UK d Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK Phytochem. Anal. 2016, 27, 217–221 Copyright © 2016 John Wiley & Sons, Ltd. Research Article Received: 2 February 2016, Revised: 11 March 2016, Accepted: 14 March 2016 Published online in Wiley Online Library (wileyonlinelibrary.com) DOI 10.1002/pca.2619 217