1. Department of Biosciences, University of Eastern Finland, Box 1627, 70211 Kuopio, Finland
2. Department of Pharmaceutical Chemistry, Biocenter Kuopio, University of Eastern Finland, Box 1627, 70211 Kuopio, Finland
3. Natural Product Research Laboratories, University of Eastern Finland, Box 111, 80101 Joensuu, Finland
4. AgriFood Research Finland, 31600 Jokioinen, Finland