molbank Short Note α-d-Glucopyranosyl-(1→2)-[6-O-(l-tryptophanyl)-β- d-fructofuranoside] Kwaku Kyeremeh 1, * , Samuel Kwain 1 , Gilbert Mawuli Tetevi 1 , Anil Sazak Camas 2 , Mustafa Camas 2 , Aboagye Kwarteng Dofuor 3 , Hai Deng 4 and Marcel Jaspars 4 1 Marine and Plant Research Laboratory of Ghana, Department of Chemistry, School of Physical and Mathematical Sciences, University of Ghana, P.O. Box LG 56, Legon-Accra, Ghana; kwainsamuel75@gmail.com (S.K.); gilberttet@gmail.com (G.M.T.) 2 Department of Bioengineering, Munzur University, 62000 Tunceli, Turkey; anilsazak@gmail.com (A.S.C.); mustafacamas@gmail.com (M.C.) 3 Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P. O. Box LG 54 Legon-Accra, Ghana; akdofuor@st.ug.edu.gh 4 Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Old Aberdeen, AB24 3UE Scotland, UK; h.deng@abdn.ac.uk (H.D.); m.jaspars@abdn.ac.uk (M.J.) * Correspondence: kkyeremeh@ug.edu.gh; Tel.: +2-3320-789-1320 Received: 13 May 2019; Accepted: 14 June 2019; Published: 16 June 2019   Abstract: The Mycobacterium sp. BRS2A-AR2 is an endophyte of the mangrove plant Rhizophora racemosa G. Mey., which grows along the banks of the River Butre, in the Western Region of Ghana. Chemical profiling using 1 H-NMR and HRESI-LC-MS of fermentation extracts produced by the strain led to the isolation of the new compound, α-d-Glucopyranosyl-(1→2)-[6-O-(l-tryptophanyl)-β- d–fructofuranoside] or simply tortomycoglycoside (1). Compound 1 is an aminoglycoside consisting of a tryptophan moiety esterified to a disaccharide made up of β-d-fructofuranose and α-d-glucopyranose sugars. The full structure of 1 was determined using UV, IR, 1D, 2D-NMR and HRESI-LC-MS data. When tested against Trypanosoma brucei subsp. brucei, the parasite responsible for Human African Trypanosomiasis in sub-Saharan Africa, 1 (IC 50 11.25 μM) was just as effective as Coptis japonica (Thunb.) Makino. (IC 50 8.20 μM). The extract of Coptis japonica (Thunb.) Makino. is routinely used as laboratory standard due to its powerful antitrypanosomal activity. It is possible that, compound 1 interferes with the normal uptake and metabolism of tryptophan in the T. brucei subsp. brucei parasite. Keywords: endophytes; mangroves; glycosides; trypanosomes; antiparasitics 1. Introduction Carbohydrate-based natural products constitute a very potent group of compounds with promising prospects as future drugs [1]. Currently, there are many carbohydrate natural product derived compounds that are already drugs and these include: The polysaccharides, tragacanth (diarrhea and constipation) [2], astragalus (cancer) [3], lentinan (cancer and hepatitis B) [4], tremella (cancer and chronic bronchitis) [5,6], icodextrin (peritoneal dialysis) [7] and pentosan polysulfate (interstitial cystitis) [8]; the oligosaccharides, lactulose (constipation and hepatic encephalopathy) [9], sucralfate (active duodenal ulcers) [10]; and the monosaccharides, miglitol (anti-diabetic) [11] and meglumine (excipient) [12]. Glycosylated natural products are defined as natural compounds where the carbohydrate part (glycone), either monomers or oligomers of different structures, is covalently bound to another chemical structure (aglycone). The aglycone encompasses natural product scaffolds such as terpenes, steroids, alkaloids, ribosomal and non-ribosomal peptides, modified amino acids, polyketides, macrolides, flavonoids, polyenes, coumarins, anthracyclines, iridoids and lignans [13–16]. Glycosides display Molbank 2019, 2019, M1066; doi:10.3390/M1066 www.mdpi.com/journal/molbank