1. School of Pharmacy, Department of Pharmaceutical Chemistry, Pharmacognosy, P.O. Box 1068 Blindern, N-0316 Oslo, Norway, MATFORSK, The Norwegian Food Research Institute, Osloveien 1, N-1430 Ås, Norway, and The Norwegian Institue of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo, Norway