Vale, N.Gouveia, M.J.Botelho, M.Sripa, B.Suttiprapa, S.Rinaldi, G.Gomes, P.Brindley, P.J.Correia da Costa, J.M.2014-01-232014-01-232013-08-20Parasitol Int. 2013 Dec;62(6):535-42. doi: 10.1016/j.parint.2013.08.001. Epub 2013 Aug 20.1383-5769doi:10.1016/j.parint.2013.08.001http://hdl.handle.net/10400.18/1876Liquid chromatography in tandem mass spectrometry (LC-MS/MS) has emerged as an informative tool to investigate oxysterols (oxidized derivatives of cholesterol) in helminth parasite associated cancers. Here, we used LC-MS/MS to investigate in soluble extracts of the adult developmental stage of Opisthorchis viverrini from experimentally infected hamsters. Using comparisons with known bile acids and the metabolites of estrogens, the LC-MS data indicated the existence of novel oxysterol derivatives in O. viverrini. Most of these derivatives were ramified at C-17, in similar fashion to bile acids and their conjugated salts. Several were compatible with the presence of an estrogen core, and/or hydroxylation of the steroid aromatic ring A, hydroxylation of both C-2 and C-3 of the steroid ring and further oxidation into an estradiol-2,3-quinone.engBile AcidsFlukesOpisthorchis ViverriniOxysterolsjournal article