Phytosterols are increasingly used as health supplements in functional foods and are associated with having both positive and negative effects on health.1 In contrast to the heavily promoted health benefits of dietary phytosterol supplementation, a number of groups have identified adverse health effects of phytosterols: induction of endothelial dysfunction and increased size of ischaemic stroke; inhibition of cell growth; aggressive vascular disease in sitosterolaemic patients.2,3 Given this disparity, an investigation of their full individual biological profile is imperative in order to assure food safety. Herein we describe the de novo synthesis of pure phytosterols in multigram scale and report the first synthesis of the key phytosterol Dihydrobrassicasterol and its oxides along with a comparison of routes to Campesterol.4,5 A detailed spectroscopic analysis is included with full assignment of the 13C NMR of both phytosterols, mixtures and their precursors leading to the potential use of NMR as a tool for analysis of these sterol mixtures. A comprehensive toxicological profile of these key phytosterol oxide products (POPs) identifies critical problems with the use of phytosterol mixtures as food additives.5,6,7
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- O. Kenny, Y. O'Callaghan, N.M. O'Connell, F.O. McCarthy, A.R. Maguire and N.M. O'Brien J. Agric. Food Chem., 2012, 60 (23):5952-5961.O'Callaghan Y, Kenny O, O'Connell NM, Maguire AR, McCarthy FO, O'Brien NM. Biochimie, 2013, 95(3), 496-503.